| UMWELT & GESUNDHEIT |
GUIDELINES FOR INDOOR AIR HYGIENE IN SCHOOL BUILDINGS
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Contact: Federal Environment AgencyPostfach 140606813 Dessau-RoßlauInternet: www.umweltbundesamt.de E-mail: [email protected] Printed on 100% recycled paper
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Published by:Federal Environment Agency (UBA)Innenraumlufthygiene-Kommission des Umweltbundesamtes
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© 2008 Umweltbundesamt Berlin
Guidelines for Indoor Air Hygiene in School Buildings
Produced by the German Federal Environment Agency’s Indoor Air Hygiene Commission
Berlin, August 2008
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Guidelines for Indoor Hygiene in School Buildings
Produced by the Federal Environment Agency’s Indoor Air
Hygiene Commission
Members:
PD Dr. Wolfgang Bischof,UniversityClinicofJena,DepartmentofIndoorClimatology
Dr. Rolf Buschmann,NorthRhine-WestphaliaConsumerCentre,Düsseldorf
Dr.Thomas Gabrio,StuttgartDistrictCommissioner’sOffice,Baden-WürttembergHealthAgency(Landesgesundheitsamt)
PD Dr. Steffen Engelhart,InstituteforHygieneandPublicHealth,Bonn
Dr. Birger Heinzow,Schleswig-HolsteinSocialServicesAgency(LandesamtfürsozialeDienste),Kiel
Prof. Dr. Olf Herbarth,FacultyofMedicine,UniversityofLeipzigandHelmholtzCentreforEnvironmentalResearch(UFZ),Leipzig
Prof. Dr. Caroline Herr,BavarianHealthandFoodSafetyAuthority,Oberschleißheim
Dr. Hermann Kruse,UniversityHospitalSchleswig-Holstein,InstituteofExperimentalToxicology,Kiel
PD Dr. Susanne Lau,BerlinFreeUniversity,DepartmentofPaediatricPneumol-ogyandImmunology
Dr. Wolfgang Lorenz,InstituteforIndoorEnvironmentDiagnostics,ToxicologyandBuildingPhysics,Düsseldorf
Dr. Inge Mangelsdorf,FraunhoferInstituteforToxicologyandExperimentalMedicine,Hanover
Prof. Dr. Volker Mersch-Sundermann,InstituteofEnvironmentalMedicineandHospitalEpidemiology,Freiburg
Dipl.-Chem. Wolfgang Misch,GermanInstituteforConstructionEngineering(DIBT),Berlin
Prof. Dr. Henning Rüden,HELIOSHospitalGroup,Berlin
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Dr. Helmut Sagunski,HamburgDepartmentofHealthandSocialServices(BehördefürSozialesundGesundheitderFreienHansestadtHamburg)
Prof. Dr. Tunga Salthammer,FraunhoferInstituteforWoodResearch,Wilhelm-Klauditz-Institut(WKI),Braunschweig
Prof. Dr. Klaus Sedlbauer,FraunhoferInstituteofBuildingPhysics,Valley
The following also contributed their expertise:
Dipl.-Ing. (FH) Torsten Fenske,FederalMinistryofTransport,BuildingandUrbanDevelopment,Berlin
Dr. Andreas Gies,FederalEnvironmentAgency,Berlin
Dipl.-Ing. Friedrich Hamp,IntegriertesPlanen-Architekten-Ingenieure,Munich
Dr. Wolfgang Heger,FederalEnvironmentAgency,Berlin
Dipl.-Ing. Hans-Dieter Hegner, FederalMinistryofTransport,BuildingandUrbanDevelopment,Berlin
Jens Küllmer,FederalMinistryfortheEnvironment,NatureConservationandNuclearSafety,Bonn
Dr. Heinz-Jörn Moriske,FederalEnvironmentAgency,Berlin
Dr. Friederike Neisel,FederalInstituteforRiskAssessment,Berlin
Dr. Wolfgang Plehn,FederalEnvironmentAgency,Berlin
Dr. Regine Szewzyk,FederalEnvironmentAgency,Berlin
Dr Birgit Wolz,FederalMinistryfortheEnvironment,NatureConservationandNuclearSafety,Bonn
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Contents
General
I Introduction, objectives................................................................................................ 7
. I-1.The.issue............................................................................................................... 7
. I-2.Purpose.and.target.groups............................................................................... 8
. I-3.Structure.of.the.guidelines............................................................................... 9
. I-4.Current.situation.in.German.schools............................................................ 10
. I-5.Parameters......................................................................................................... 12
II Terms and regulations ................................................................................................ 13
III Further reading........................................................................................................... 14
Part A Hygiene requirements in the practical running of schools
. A-1.General.hygiene.requirements..................................................................... 17
. A-2.Cleaning.procedures...................................................................................... 19
. A-3.Ventilation.requirements............................................................................... 24
. A-4.Requirements.for.and.cleaning.of.school.swimming.pools..................... 26
. A-5.Minor.building.works.and.renovations....................................................... 28
. A-6.Workshops,.laboratories.and.home.economics.practical.areas.............. 32
. A-7.Copiers,.printers.and.PCs............................................................................... 34
Part B Indoor air pollutants in schools
. B-1.Inorganic.gases................................................................................................ 35
. B-2.Volatile.organic.compounds.(VOCs)............................................................. 39
. B-3.Formaldehyde.................................................................................................. 52
. B-4.Semi-volatile.organic.compounds.(SVOCs).................................................. 54
. B-5.Dust.................................................................................................................... 60
. B-6.Fibre.dust.......................................................................................................... 63
. B-7.Biological.substances...................................................................................... 68
. B-8.Radiation.(Radon)............................................................................................ 72
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Part C Structural and indoor climate requirements
. C-1.Structural.requirements,.fixtures.and.fittings.for.indoor.areas............... 75
. C-1.1.Building.shell................................................................................................ 76
. C-1.2.Extensions.and.conversions........................................................................ 79
. C-1.3.Fixtures.and.fittings.for.indoor.areas........................................................ 84
. C-2.Building.climate.............................................................................................. 86
. C-2.1.General.physiological.requirements......................................................... 86
. C-2.2.Technical.requirements............................................................................... 88
. C-2.3.Ventilation.technology................................................................................ 92
. C-2.4.Acoustic.requirements................................................................................. 93
Part D Procedures in problem cases
. D-1.Basic.procedures.............................................................................................. 99
. D-2.Case.studies.................................................................................................... 102
. D-2.1.Mineral.fibres.from.suspended.ceiling.construction........................... 102
. D-2.2.Chloronaphthalene.in.prefabricated.school.buildings........................ 103
. D-2.3.Odour.pollution.in.classrooms.after.the.long.holidays....................... 104
.D-2.4.Persistent.indoor.air.pollution.resulting.from.the.use.of...solvent-based.cleaning.product.on.woodblock.floors......................... 106
. D-2.5.Indoor.air.pollution.from.dibasic.dimethyl.esters.(DBE)..................... 107
. D-2.6.Health.problems.in.the.new.wing.of.a.primary.school...................... 109
Part E Remediation guidelines and procedures
. E-1.Asbestos............................................................................................................111
. E-2.Polychlorinated.biphenyls............................................................................ 112
. E-3.Pentachlorophenol........................................................................................ 113
. E-4.Polycyclic.aromatic.hydrocarbons................................................................114
Appendices
Appendix 1: (Specimen) hygiene plan for schools...................................................................117
Appendix 2: Index............................................................................................................... 129
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GENERAL
I Introduction, objectives
I-1 The issue
Airpollutantsinsideschoolspresentahygieneproblem.Theindoorpol-lutionobservedinsideschoolbuildingscanbetracedbacktoavarietyofcauses,suchaspoorconstruction,failingsinventilationengineering,incorrectventilationroutines,andtheuseofparticularbuildingmaterials,fittingsorcleaningproductswhichreleasechemicalsintotheair.Microbialproblems(mouldgrowth)alsoplayasignificantpartinschoolbuildings.
Inrecentyearstherehasbeenmuchdiscussionabouthealthyandhygi-enicallyacceptableindoorairqualityinschools.Someschoolshavebeenextensivelyrenovatedinthelastfewyearsbecauseofsuspectedasbestos,PCBsandotherindoorpollutants.Neverthelesstherearestillverymanyschoolswhosebuildingsareindireneedofmodernisationonaccountofinadequatebuildingmaintenanceworkandlackoffinanceatthelocalauthority.TheintroductionoftheBuildingEnergyConservationOrdinance[Energieeinsparverordnung,EnEV]in2002(amendedin2007)placesnewdemandsonallthoseinvolvedinthemodernisationofschoolbuildings.Theoutershellandthewindowsareintentionallymadeairtightinordertomeetenergyconservationregulations.Thedisadvantagecanbeanincreaseinchemicalandbiologicalsubstancesintheairinsideifthereisinadequateventilation.Therefore,ifschoolbuildingsrequireupgradingforenergyefficiencyorotherreasons,specificregulationsmustbeobservedsothatin-doorairhygieneproblemsdonotariselater.Theseguidelinessetoutwhatshouldbetakenintoaccountfromahygieneperspectiveandshouldhelptoidentifysolutions.
Inthe2000“GuidelinesforIndoorAirHygieneinSchoolBuildings”theFederalEnvironmentAgencydrewattentiontohygieneproblemsandcleaninginschools.Newchallengessuchastheproblemsofsuspendedpar-ticulatematterandcarbondioxideandtheneedtoupgradebuildingstomeetenergyefficiencystandardshavehowevermadeupdatingnecessary.
Newchemicalsubstancestobefoundintheairinsideschoolbuildingsandtheirsignificanceforhygienearedealtwithintheguidelines,asistheproblemofsuspendedparticulatematterinschools,theemissionofultra-fineparticlesfromprinters,andtheissueofmouldgrowth.Onechapterisdevotedentirelytotheimportantsubjectofventilation.Here–inschoolsaselsewhere–aparadigmshiftmaypossiblyoccur,sinceinsomecases
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naturalventilationviawindowsisnolongeranadequatelypracticalandlastingwayofachievingacceptableindoorairquality.Thisisespeciallythecasewiththeconcentrationofcarbondioxide,whichwasrecognisedbyPettenkofermorethan150yearsagoastheindicatorof“bad”airintheindoorenvironment.Todaycarbondioxideisonceagainameasureofthequalityofindoorairinschoolbuildings.Howtotakeeffectiveremedialac-tionagainsttheCO
2probleminclassroomsissetoutintheGuidelines.
I-2 Purpose and target groups
The“new”Guidelinesareintendedasaresponsetocurrentrequirementsinschoolpractice.Therecommendationsmadehereaimtohelptoavoidmistakes–fromanindoorairqualityperspective–inmodernisingschoolbuildings,andtoprovidehygiene-specificsupportintheplanningofnewschoolbuildings.
TheGuidelinesrelateprimarilytoclassroomsandassemblyroomsinschoolsandvocationalcollegesinwhichpupilsregularlyhavelessons.Theyshouldbeappliedbyanalogytoothertypesofschoolsandcarefacilitiessuchasdaynurseries.Manyrecommendationsarealsovalidforindoorspacesinpublicbuildingsotherthanschools.Otherstatutoryregulations(OrdinanceonHazardousSubstances[Gefahrstoffverordnung],etc.)whichapplytospecialisttechnicalareasofschoolbuildings(forexample,homeeconomicspracticalareas,workshops,laboratories)willnotbeaddressedfurtherintheseGuidelines.
TherecommendationsmadeintheGuidelinesalsoapplytotemporaryschoolbuildings(“demountables”).
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I-3 Structure of the Guidelines
The Guidelines are laid out as follows:
IntheGENERALSECTIONthetargetsoftheGuidelinesandthetargetgroupsareaddressed.ThecurrentindoorhygienesituationinGermanschoolsisdescribed,followedbytheparameterswithregardtope-ripheralissueswhichwillnotbedealtwithfurther.Varioustermsareexplainedandtherearesuggestionsforfurtherreadingonthesubjectofindoorairhygiene.
PART Adealswiththehygienerequirementsinthepracticalrunningofschools.Besidesgeneralrequirementsformaintenanceandoperationtheimportantissuesofcleaningandventilationareconsidered,aswellasminorbuildingworks.
PART Bprovidesanoverviewofimportantchemicalandbiologicalcontaminantsinschools.
PART Clooksatbuildingandairconditioningrequirements.Theimportantissueofacousticrequirementsisalsoaddressed.
PART Dshowshowtodealpracticallywithproblemcasesandlistscasestudieswith“typical”procedures.
PART Eprovidesabriefoverviewofexistingrenovationguidelines
TheAPPENDIXcontainsaspecimenhygieneplanforschoolsandanindex.
TheGuidelinesareintendedontheonehandforteachers,pupilsandparentsasthosedirectlyorindirectlyaffected,andfortheschoolgovernorsandthosepeo-pleateducationauthorities,planningdepartments,departmentsofhealthandtheenvironmentwithresponsibilityforschoolsontheotherhand.InadditiontheGuidelinesprovideinformationforallprofessionalgroupsinvolvedinplan-ning,building,renovatingormodernisingschoolbuildings.
Who are the Guidelines aimed at?
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I-4 Current situation in German schools
TheconditionofschoolsinGermanyisoftenunsatisfactoryintermsofthefabricofthebuildings.Olderbuildingsexhibitproblemssuchasill-fittingwindows,leakinessandsignsofwearandtearonbrickworkandroofs,aswellasdampdamageasaresultofplumbingleaks.Thenumberofnewbuildingserectedafter1990iscomparativelysmall.
Todaytherearearound34,000mainstreamschoolsandabout10,000voca-tionalcollegesinGermany.
Amongthemain(air)contaminantsinschoolsare:
Increasedcarbondioxideresultingfrominadequateventilationandairtightwindows.
Excessivedampinthestructureofthebuildingorintheindoorair,resultinginmicrobialgrowth.
Emissionsfrombuildingmaterials,fixturesandfittings.
Diverseodoursinthecaseofinadequateventilation.
Emissionsfromcleaningmaterials.
Possiblereleaseofdustandfumesintechnologyandsciencelessons.
Particulatematterarisingfromdischargesfromoutdoorandindoorsources.
Amongtheproblemsmentionedbypupils,parentsandteachers inrelationtobeinginschoolaregeneraldisorderssuchasheadaches,fatigueandpoorcon-centration.Furthermore,symptomssuchas irritationsof theupperrespiratorytractsandeyes,sinusinfectionsandtheoccurrenceofallergicsymptomscanalsobetracedbacktotimespentinschools.
What sort of health problems are reported after spending time in schools?
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Manyschoolbuildingsareclearlyinneedofrenovationonaccountoftheirgreatageandmanyyearsofintensiveuse.Inrecentyearsthefireandhealthandsafetyregulationshavealsobecomeevermorestringent.TheBuildingEnergyConservationOrdinancedemands,amongstotherthings,thatinnew-buildsandcomprehensiverenovationsofexistingbuildingstheoutershellismadeairtighttominimisetheuseofprimaryenergy.Thedis-advantagewhenthereisinadequateventilationcanbeapossibleaccumu-lationofthechemicalandbiologicalsubstancesreleasedindoors.
Unfortunately,manylocalauthoritieslackthemoneyforcomprehensiveandspecialistrenovations.Theconsequenceisdamppenetrationthroughgapsinwalls,roofsandpipework.Ill-fittingwindowsareactuallyarealadvantagefromahygieneperspective,astheyhelptoallowaminimumofaircirculationinclassroomsevenifthewindowsanddoorsareclosed.However,ill-fittingwindowsleadtoenergylossandmayexposepupilsandteacherstodraughtsduringlessons.
Theremediationnecessary,i.e.theextentoftherepairs,modernisationandrenovationofschoolbuildings,dependsontheactualconditionofthebuildingineachcase–oldandnewbuildingsareequallyaffected.Becauseofthedemandsontheuseofschoolbuildings,particularlytheclassrooms,regularmaintenanceandrepairsareextremelyimportantinordertoavoidstructurallyrelatedhygieneproblemslater.
Ifextensiverenovationworkisduetotakeplace,acomprehensiveair-con-ditioningschemeshouldbeincludedintherenovationplans,inordertoimprovetheventilationsituationduringlateruse.Thiscaninvolveair-con-ditioningsolutions,butcouldalsobeadesignforanimprovedventilationregime.Sensor-operatedsolutions(openingthewindowswhenthereistoomuchcarbondioxideintheair)areequallypossible.
Noisecontrolcanbeanotherprobleminschoolbuildings.Manyclassroomssufferfromundesirablereverberation.Therecanthenbesubstantialinter-ferencetocommunicationandauralcomprehensionbetweenteachersandpupils.
Justasimportantasgoodacousticsisadequateandevenlighting.Windowsofadequatesizeareinanycasecompulsory.However,ifthesefaceexclu-sivelywestandeast,itcancauseexcessiveheattobuildupintheroomsinsummer.South-facingwindowsaregenerallylessofaprobleminthisre-spect,contrarytolong-standingopinion,becausethesunisrelativelyhighintheskyatmidday,makingiteasiertoemployshadingatthewindows.
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Theneedtotakeprecautionsagainstoverheatingofroomsinsummerwillincreaseinthecourseoffutureclimatechanges.
I-5 Parameters
Oneindoorhygieneproblemofthelastdecadehasrecentlybeencon-signedtothepast–tobaccosmoke.OwingtothelawsprotectingagainstthedangersofpassivesmokingwhichhavenowcomeintoforceinalmostallGermanLänder,ageneralbanonsmokinginschoolsandschoolplay-groundsappliesthroughoutGermany.Smokingroomsarenotpermittedinschools.
Under Länder building regulations, it is strictly prohibited to use windowlessroomsforlongperiodsofoccupation,andthereforealsoasclassroomsinschools.
Is it permitted to use windowless rooms as classrooms?
Tobacco smoke: thenegativehealtheffectsof tobacco smokearewell enoughknown. There is an absolute ban on smoking in school buildings and on thewholeschoolpremises.
What is not covered in these guidelines?
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II Terms and regulations
AccordingtoarecentstudyaspartoftheFederalEnvironmentAgency’s2007NationalHealthSurveyofChildrenandAdolescents,childrenagedbetween3and14spend90%ofthedayindoorsinwinter.Eveninsummeradolescentsspendpartofthedayinenclosedspaces.Theindoorenviron-mentincludesthehome,school,nurseryschools,theatres,cinemas,librar-ies,sportshalls,departmentstores,discothequesandtransport.Thus,fromahygieneperspective,thestudyandreductionofindooraircontaminantsisofcentralimportanceforhealthandwell-being.
Anadhocworkinggroup,madeupofmembersoftheFederalEnviron-mentAgency’sIndoorAirHygieneCommission(IRK)andtheWorkingGroupoftheSupremeHealthAuthoritiesoftheFederalStates(AOLG),aredevisingguidelineindoorairvaluesforsinglesubstancesbasedonaproceduralmodelpublishedin1996(cf.SectionB-2).Accordingtothis,twoguidelinevaluesaregenerallyestablishedforindooraircontaminants.ValueII(RWII)isderivedonahygiene/toxicologybasis,takingintoac-countbothpopulationgroupswithsensitivereactionsandchildren,andrepresentstheconcentrationofasubstancewhich,ifreachedorexceeded,requiresimmediateaction,sincethisconcentrationislikelytoendangerhealth,especiallyinpeoplewithsensitivities,iftheyspendalongtimeintherooms.Theneedforactionshouldbeunderstoodastheneedforimmediateinspection,e.g.withaviewtodecidingonremedialmeasurestoreduceexposure.ValueI(RWI)iscalculatedfromRWII,takingintoaccountaconventionallyestablishedsafetyfactor(generallyof10),andcanserveasthetargetremediationvalue.IfavalueisbelowRWIwhenasinglesubstanceisexamined,accordingtocurrentknowledgenodamagetohealthistobeexpected,eveninthecaseoflifelongexposuretothesub-stanceconcerned.ForprecautionaryreasonsactionalsoneedstobetakenintheregionbetweenRWIandRWII,forinstance,toincreaseventilation.
Ingeneral,pollutionintheairinaclassroomshouldbetreatedandassessedinthesamewayaspollutioninthehome.Healthandsafetyatworkregulations,whichapplytoindividualareasoftheschool(workshops,etc.),donotprecludethis.Airpollutionlimitvaluesapplicabletoworkplacescontaminatedbyindus-trialproductionprocessescannotbeappliedtotheinsideofschools.
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Anoverviewoftheindoorairguidelinevaluesderivedonthebasisofthismodel,whichalsoappliestoindoorareasinschools,canbefoundonlineatthefollowinglink:http://www.umweltbundesamt.de/gesundheit/innenraumhygiene/richtwerte-irluft.htm.
III Further reading
The following collection includes a range of literature intended to provide the reader with further information on indoor air hygiene.
AmtderNiederösterreichischenLandesregierung,AbteilungUmwelthygiene:LeitfadenfürdieInnenraumlufthygienebetreffendVorbeugung,Untersuchung,BewertungundSanierungvonSchim-melpilzbelastungeninWohngebäuden[LowerAustrianstategovern-ment,DepartmentofEnvironmentalHealth:Guidelinesforindoorairhygienewithregardtotheprevention,investigation,assessmentandremediationofmouldcontaminationinresidentialbuildings].St.Pölten2007.http://www.noe.gv.at/bilder/d25/Schimmelpilzleitfaden.pdf
BayerischesLandesamtfürGesundheitundLebensmittelsicherheit:LuftqualitätinöffentlichenInnenräumen–FrischeLuftanbayerischenSchulen[BavarianHealthandFoodSafetyAuthority:Airqualityinpublicindoorspaces–freshairinBavarianschools].http://www.lgl.bayern.de/gesundheit/umweltmedizin/projekt_luft.htm
BerufsgenossenschaftderBauwirtschaft(BGBAU):Gesundheitsgefähr-dungendurchbiologischeArbeitsstoffebeiderGebäudesanierung(BGI858).HandlungsanleitungzurGefährdungsbeurteilungnachBiostoffverordnung[Buildingtradeassociation(BGBAU):Healthhaz-ardsfrombiologicalmaterialsusedinbuildingrenovation(BGI858).InstructionsforriskassessmentinaccordancewiththeOrdinanceonBiologicalAgents].(2006)http://www.bgbau-medien.de/site/asp/dms.asp?url=/zh/bgi858/titel.htm
FreieundHansestadtHamburg:FrischerWindinSchulen.Informa-tionsbroschüre.Hamburg,BehördefürWissenschaftundGesundheit[FreeandHanseaticcityofHamburg:Abreathoffreshairinschools.Informationleaflet.HamburgMinistryofScienceandHealth].(2005)
InstitutfürangewandteHygiene:ÖsterreichischeSchulen–Hygiene-plan[InstituteofAppliedHygiene:Austrianschools–hygieneplan].Graz(2007)www.schule.at/gesundheit/hygieneplan2007.pdf
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LandesgesundheitsamtBaden-Württemberg:SchimmelpilzeinInnen-räumen–Nachweis,Bewertung,Qualitätsmanagement.LGA-Berichte,[Baden-WürttembergHealthAgency:Mouldinindoorenvironments–detection,evaluation,qualitymanagement.HealthAgencyreports]Stuttgart(2001)(revised2004)
LandesgesundheitsamtBaden-Württemberg:HandlungsempfehlungfürdieSanierungvonmitSchimmelpilzenbefallenenInnenräumen[Baden-WürttembergHealthAgency:Recommendedprocedurefortheremediationofindoorareasattackedbymould],2ndrevisededition,Stuttgart(2006)
LandesgesundheitsamtBaden-Württemberg:MusterhygieneplanfürSchulenundähnlicheGemeinschaftseinrichtungen[Baden-Württem-bergHealthAgency:Specimenhygieneplanforschoolsandsimilarcommunityinstitutions].LGA,Stuttgart(2005)
NiedersächsischesLandesgesundheitsamt(NLGA):LüftungsempfehlungfürArbeitsräume(Büro-undUnterrichtsräume)[GovernmentalInsti-tuteofPublicHealthofLowerSaxony:Recommendedventilationforindoorworkplaces(officesandclassrooms)].NLGA,Hanover(2004)
NiedersächsischesLandesgesundheitsamt(NLGA):„AufatmeninSchulen“–LuftqualitätundRaumklimainUnterrichtsräumen[Govern-mentalInstituteofPublicHealthofLowerSaxony:„Breathedeeplyinschools”–airqualityandindoorclimateinclassrooms].NLGA,Han-over(2005)
NiedersächsischesLandesgesundheitsamt(NLGA):Rahmenhygienep-lanfürSchulen(Entwurf)[GovernmentalInstituteofPublicHealthofLowerSaxony:Frameworkhygieneplanforschools(draft)],Hanover(2007)
Rahmen-HygieneplanfürSchulenundsonstigeAusbildungseinrichtun-gengemäߧ36Infektionsschutzgesetz.Länder-ArbeitskreiszurErstel-lungvonHygieneplänennach§36IfSchG[FrameworkhygieneplanforschoolsandothereducationalestablishmentsinaccordancewithArticle36ProtectionagainstInfectionsAct.Federalstates’workinggroupforthecreationofhygieneplansinaccordancewithArticle36ProtectionagainstInfectionsAct],Potsdam(2003)
Umweltbundesamt:LeitfadenzurVorbeugung,Untersuchung,Bew-ertungundSanierungbeiSchimmelpilzwachstuminInnenräumen(Schimmelpilz-Leitfaden)[FederalEnvironmentAgency:Guidelinesontheprevention,investigation,assessmentandremediationofmouldgrowthinindoorareas],Berlin/Dessau2002
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Umweltbundesamt:LeitfadenzurUrsachensucheundSanierungbeiSchimmelpilzwachstuminInnenräumen(Schimmelpilz-Sani-erungsleitfaden)[FederalEnvironmentAgency:Guidelinesoniden-tifyingthecauseandontreatingmouldgrowthinindoorspaces].Berlin/Dessau2005
Umweltbundesamt:Bauprodukte:SchadstoffeundGerüchebestimmenundvermeiden[FederalEnvironmentAgency:Buildingmaterials:Iden-tifyingandavoidinghazardoussubstancesandodours].Dessau2006
UnfallkassedesLandesNordrhein-Westfalen(2008):UmsetzungderGe-fahrstoffverordnunganSchulenTeil1und2[NorthRhine-WestphalianAccidentInsurance(2008):ImplementationoftheHazardousSub-stancesOrdinanceinschoolsparts1and2]:availableat<http://www.unfallkasse-nrw.de/index.php?id=4&no_cache=1>linktodownloadthedocu-ments“PräventioninNRW3und4-UmsetzungderGefahrstoffverord-nunganSchulenTeil1und2”[PreventioninNorthRhine-Westphalia3and4-ImplementationoftheHazardousSubstancesOrdinanceinschoolsparts1and2]
UnitedKingdom:DepartmentforCommunitiesandLocalGovernment:TheBuildingRegulationDocuments.BuildingBulletin101,VentilationofSchoolBuildings.London(2006)
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PART A: Hygiene requirements in the practical running of schools
A-1 Generalhygienerequirements
Theseguidelinesrelatetoairhygienequestionsinschoolbuildings.How-ever,inthepracticalrunningofschoolsthereareoftenaspectsoverandaboveairhygienetoconsider.
Justasinotherbuildings,specificfundamentalhygienerequirements,orrathergeneralhygienerequirements,mustbemetinschools,inorderforittobepossibletospendtimeinthebuildingwithoutexperiencinghealth-relatedproblems.
Includedinthegeneralhygienerequirements(someofthepointslistedcanonlybeimplementedwhenplanningnew-builds)are:
Theschoolsiteshouldbelocatedfavourablywithrespecttoairbornepollut-antsinthesurroundingair,i.e.thereshouldbeaslittlepollutionbyhazard-oussubstancesaspossibleinthevicinity.Thereshouldbelowtrafficandindustrialnoiselevelsandasaferoutetoschoolforpupils.Converselythenoiseemissionsfromtheschoolitselfshouldasfaraspossiblenotcreateanysignificantnuisancetotheneighbourhood.
Theclassroomsshouldbeofsufficientsizeandbearrangedpracticallyinrelationtothewaythesunmovesround.Wheretheproportionofglassinthefaçadeexceeds50%,asisusualinschoolconstruction,allfaçades,withtheexceptionofwindowsfacingduenorth,requireshading.Thismusthavevariablecontrols.
Adequatelightfromdaylightand–tosupplementit–fromartificiallightingshouldbeprovidedatalltimesofdayandthroughouttheyear.Consequentlythedepthoftheroomshouldnotexceedtwotothreetimesitsheight.Thelightreflectanceofthecomponentsurfacesshouldbeashighaspossible(canbeachievedbymeansonlightcoloursonwallsandceilings).
Effectivestructuralnoiseinsulationshouldpreventnoisetransfertoneigh-bouringrooms,corridors,etc.Theclassroomsshouldhavelowreverbera-tiontimesforbetterspeechintelligibility(DIN[GermanInstituteforStand-ardisation]180412004/2005;Acousticalqualityinsmallandmedium-sizedrooms).
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Windowsorotherventilationoptionsshouldpermit,throughnaturalventi-lation,thereductionoftheconcentrationofairpollutantsbeingproducedintheroom.Allwindowsshouldbeeasytoopen.
Inareasinwhichworkingwithhazardoussubstancesisarequirement,suchasinlaboratories,mechanicalventilationisabsolutelyessential.Inthecaseofextremelypollutedoutsideairconditionstheinstallationofair-con-ditioningsystemsshouldbeconsidered.
Allareasoftheschoolbuildingshouldbeequippedwithadequateheating,wherebytheradiatorsshouldbeofadequatedimensions,ifpossibleshouldberunatlowtemperatures,andshouldbeeasytoclean.
Thefurnishingsandequipmentintheroomsshouldbeasfreeaspossibleofemissionshazardoustohealth.Whenpurchasingnewfurnitureattentionshouldbepaidtoenvironmentalqualitylabels(cf.SectionA-5).
Propercloakroomsshouldbeavailableinsufficientnumberssothatwetclothingcandryandair.Forfiresafetyreasonslockersandcoatpegsareoftennotlocatedincorridorsnowadays,butintheclassrooms.Thismakesadequateventilationanddehumidificationintheseareasallthemoreim-portant.
Asufficientnumberoftoiletsequippedwithwashbasinsshouldbeavailableforpupilsandteachers.Thefacilitiesmustbecleanedandservicedregularly.
Playgroundsandindoorrecreationroomsofsufficientsizeshouldbeavail-ableforuseatbreaktimes.
Allareasofthebuildingshouldbeeasytoclean.
Regulations in individual Länder, in accordance with which windows havebeenstructurallyormanuallyalteredforsafetyreasonssothattheycannotbeopened–forexample,topreventsomeonefallingoutofthewindow–areunac-ceptableintheopinionoftheIndoorAirHygieneCommission.Accidentsmustbepreventedthroughothermeasures(includingallpupilsleavingtheclassroomduringbreaks,theclassroomsbeinglockedduringbreaks).
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A-2 Cleaning procedures
Cleaningproceduresmustbecarriedoutregularlyandproperlyinschoolsonaccountoftheintensiveuse,includingbyvulnerableusergroups.TheminimumrequirementsforcleaningschoolbuildingsandsportsfacilitiesbelongingtothemaresetoutinDIN77400“Cleaningservices–schoolbuildings–requirementsforcleaning”.Thisappliesregardlessofwhetherthecleaningisundertakenbytheschool’sownemployeesorbycleaningagencies.
IntheintroductiontotheaforementionedDINstandarditisnotedthatcleanlinessandhygieneareofparticularimportanceinschoolbuildingsandthattheenvironmentinwhichchildrenandyoungpeopleareedu-catedinfluencestheirhealthaswellastheirownperceptionofhygieneandtheirhabitsinthatrespect.Furthermore,itstatesthatparticularimpor-tancemustbeattachedtoschoolcleaningrequirements,regardlessoftheprevailingbudgetsituationwithinthelocalauthorities,andtothecleaningintervalsresultingfromit.
AccordingtoDIN77400oneofthegeneralrequirementsforhygieniccleaningofschoolbuildingsisthatthedustconcentrationiskeptwithinacceptablelimitsthroughsuitablecleaningmethods(e.g.washing).Whenselectingthecleaningmethodsandsystemsthelatesttechnologyshouldbeused,takingintoaccountenvironmentalconsiderations.
Whenestablishingcleaningintervalsinindividualschoolbuildingslocalconditionsmustbegivenparticularconsideration.Factorstobearinmindincludelocation,use(andalsoextracurricularuse),schoollayout,frequencyofuse,buildingfabric,natureoftheexternalgrounds(withunsurfacedar-easconsiderablymoredirtcanbeexpectedtobebroughtin)andseasonalinfluences.
Besides hygienically impeccable structural conditions, good accessibility to allroomsandareas,especiallywithregardtomakingcleaningeasy,theprovisionoflow-emissionequipment,andregularheatingandventilationarethebestprereq-uisitesforahygienicallysafesituationinschools.
What general hygiene considerations should be taken into account in the practical running of a school?
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ThecleaningintervalssetoutinDIN77400areminimum cleaning frequencies.InDIN77400itisemphasisedthat,dependingonlocalconditionsandthefactorsmentionedabove,morefrequentcleaningthanspecifiedinDIN77400maybenecessary.
Thefollowingcleaningproceduresarebasedontheseminimum cleaning frequenciesandshouldthereforenotbeappliedprescriptivelytoalllocalsituationsandseasonalconditionsequally.
Corridorsandstairwellstogetherwithclassroomsandteachingareasarethemostfrequentlyusedspacesinaschool.Theseareasbecomedirtyquickly.Theentrancearea,thetrafficareasofthegroundfloorandthestairstothefirstfloorshouldbecleaneddaily,evenseveraltimesdailyifnecessaryinwinter,whenmoremudisbroughtinfromoutside.Theothercorridorsandstaircasesshouldbecleanedatleasteveryotherdayinsummer,andmoreofteninwinterifnecessary.
Fromahygieneviewpointwashing,havingfirstremovedloose,coarsedirt,offersthebestoptionforeliminatingthevariouscontaminantsbroughtin-side.Dependingonthenatureandcompositionofthefloorstobecleaneditmaybesufficienttoaddeithersurfactantstothewashingwater,orelsespecialistcleaners(forflexiblefloor-covering)mustbeused.Morepreciseinstructionsinthisregardshouldbestipulatedineachindividualcaseafterconsultationwiththecleaningcontractorsorthefloormanufacturer.
Onlyinexceptionalcaseswillitbenecessarytocarryoutdisinfectantclean-ingorsurfacedisinfectionoffloorsincorridorsandstairwells.Forexample,thismaybethecaseifthereareincreasedoccurrencesofnotifiableinfec-tiousillnessesintheschool,whentherelevanthealthagencywillarrangeforappropriatemeasurestobetaken.Thisespeciallyincludesdisinfectinghandrails.Incasesofcontaminationwithblood,faecesandvomitdisinfect-ingcanalsobenecessary;however,thisshouldonlybecarriedoutbydes-ignatedstaffandunderstrictobservanceoftheschool’sexistinghygiene,ventilationandcleaningplan(seeAppendix1).
Inordertofacilitateregularwetcleaning(washing)ofcorridorsandstair-wellsinschoolsitisnecessaryfortheseareastobefittedwithsuitablefloor-ing.
Carpetsandcarpetingshouldthereforenotbeusedintheseareas(seepara-graphonCarpeting).
Classroomsandteachingareasshouldbecleanedregularly.Studieshaveshownthatperfectlyhygienicconditionscanbeachievedinclassroomsbywashingthefloorproperlyandwipingtabletopswithadampclotheveryotherday,ifexternalconditions(stateofthebuilding,localcircumstances)
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aregood.Especiallyinthewintermonthsandwithunsurfacedoutsideareas,andifthereisadditionaluse(e.g.after-schoolclubs)cleaningshouldbecarriedoutdaily.
Carpeting,whichislaidinsomeschoolsforreasonsofnoisecontrol,shouldalsobeproperlyvacuumedatleasteveryotherday,ifpossiblewithavac-uumcleanerfittedwithaHEPAfilterorwithacentralvacuumcleaningsystem(VDI[guidelinesfromtheGermanAssociationofEngineers]4709).Themanufacturer’sinstructionsshouldalsobeobserved.Inthiscase,too,morefrequentcleaningshouldbeassumedifincreaseddirtisbroughtinorthereisadditionaluse.Carpetinginclassroomsandteachingareascanposeahygieneproblem,asitismoredifficulttocleanthanhard,washablefloors.Forthisreasonlayingcarpetinginnewschoolbuildingsisnotrec-ommended.Ifcarpetshavetoberenewed,e.g.becauseofwearandtear,theyshouldifpossiblebereplacedwithhard,washableflooring.
“Cosy corners”presentaparticularhygieneprobleminschools.Theissuehereisoftensecond-hand,sometimesthreadbareupholsteredfurniture,whichisoftenpiledupwithcuddlytoyanimals,toys,cushionsandblan-kets.Iftheschoolacceptsthese“cosycorners”,whichhavefrequentlybeensetupwiththesupportoftheparents,theymustdefinitelybeincludedinthecleaningplanandcleanedthoroughlyaswellonaregularbasis,e.g.byvacuumingthematleastonceaweek.Itemskeptinthesecornersmustalsobesubjecttothecleaningprocedures.
Linoleumhasenvironmentaladvantagesowingtoitsnaturalconstituents–linseedoil,woodflour,limestoneandjute–andisoftenusedinpublicbuildings,althoughitrequiresregularspecialcarebecauseofitscomposi-tion.Whencleaningandcaringforlinoleumthereisadistinctionbetweencleaningafterinstallation,orinitialcleaning,maintenancecleaningbywashing,wipingwithadampmoporusingafloorcleaneranddeepclean-ingfollowedbyreplenishingtheprotectivefinish.Whenselectingcleaningandmaintenanceproductsforlinoleumabsolutecaremustbetakento
Areductioninpollutioninclassroomscannotbeguaranteedthroughcleaningalone.Cleaningisimportant,butthereductionofexistingsourcesofemissionsandregularventilationareequallyimportant.Throughventilationthecarbondi-oxideconcentrations(aclassicindicatorofinadequatefreshairsupply),increasedhumidityintheindoorairandpollutionbyhazardouschemicalsandparticulatematterarereduced.
Can cleaning alone improve the air quality in classrooms?
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useonlythosewithapHvaluebelowpH9,asproductsthataretooaggres-sivelyalkalineattackthenaturalmaterialsinlinoleumandcandestroythesurface.Forthisreasonsoftsoapmaynotbeusedeither.Itisrecommendedthatthecleaningstaffshouldbeobligedtoabidebythemanufacturers’relevantcareinstructions.
Sanitary areasandwashroomsincludingchanging roomsinschoolbuildingsareofparticularimportanceintermsofhygiene.Herethoroughcleaningmustbeundertakenatleastonceadayandfloorsscrubbedregularly(toremovesurfaceandground-indirt,havingfirstremovedcoarsegrit).Tiledwallsandfloorsareidealforthis.Surfacedisinfectantscanbeappropriateifnotifiableinfectiousdiseasesoccur.Inthiscasethehealthagencywillorganisesuitablemeasures.Cleaningproceduresinvolvingdisinfectantsarenotnecessaryinsanitaryareastopreventinfection,butcanbeappropriateintheeventofcontaminationofsurfacesbyfaeces,vomit,etc.
Staffrooms,school offices,administrative areas,offices and meetings roomsshouldbecleanedtwiceaweek,whilesiderooms(forlessonpreparation,teachingmaterials,etc.)shouldbecleanedatleastonceaweekandstoreroomsatleastonceamonth.
Gyms(usedonlybytheschool)andareaswithsimilarfunctions)mustbeproperlycleanedonadailybasis.Herethetypeofcleaningdependsonthefloorconstructionandthenatureofthefloorsurface.Withadditionalusebysportsclubsintheeveningandatweekendssuitablyexpandedcleaningprogrammesarenecessary.
Wheretherearekitchens and food distribution points,theprovisionsofRegula-tion(EC)No.852/2004onfoodhygieneshouldbeobserved.Thisappliesalsotoschoolmealskitchensandbythesametokenalsotohome economics kitchens.Inadditiontherelevanthygieneregulationsshouldalsobecom-pliedwithindining rooms.Thefloors,sinksandfittings,walltilesandstorageunits,tabletopsandkitchenappliances(cookers,etc.)andwashbasinsmustbecleanedoneachdayused(removingsurfaceandground-indirt,havingfirstremovedlargerdebris).
Asmoreandmoreschoolsgoovertoall-dayschooling,theyshouldensurethatasufficientnumberofwashbasinsisavailableintheschool.
Overandabovethemaintenancecleaning,deepcleaning,specialcleaningandcleaningofglassaswellascareprogrammesshouldbecarriedouttoensureadequatehygienestandardsandminimisedeterioration.Afterdeepcleaningadditionalprotectivecaremeasuresmayberequired,dependingonthetype,compositionandconditionofthesurfaces.Inparticular,pro-tectivefilmsonflooringmustbekeptingoodconditionthroughregular
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careprocedures.Athoroughcleaningandcareprogrammeinaccordancewiththecareinstructionsshouldbecarriedoutinallareasoftheschoolatleastonceayear.Thisinvolvesnotonlycleaningthefloors,butalsothefurnitureandotheritemsofequipment.
Forboththeroutinecleaningandthethoroughcleaningandcareonlycleaningproductswhichposenorisktohealthshouldbeused.Ifseveraldifferentcleaningproductsareused,acheckshouldbemadetoensurethattheproductsdonotneutraliseeachother’seffectandthatnosubstancesharmfultohealthareproducedbymixingthemtogether.Therecommen-dationsforuseshouldbefollowed.Safetyinstructionsandrisksposedbytheproductcanbeobtainedfromthesafetydatasheets.
Somesurfacedisinfectantscontainaldehyde(inrecentyearsaldehydessuchasglyoxalorglutardialdehydehavebeenusedincreasingly),quaternaryammoniumcompounds(QUATS),biguanideandamines.Somedisinfect-ants,ifusedincorrectly(toohighadoseoftheactivesubstancesinthesolu-tionemployed,inadequateorincorrectventilationmeasuresduringuse),canleadtoresiduesoftheiractiveagentsevaporatingintotheairbuildingoccupantsbreathe,resultinginharmtohumanhealth.
Forsanitaryareasapropercleanonceadayisessential;ifnecessarytheyshouldbecleanedmorefrequently.
Theentranceareauptothefirstfloorshouldbecleaneddaily,whiletheothercorridorsandstaircasesshouldbecleanedat leasteveryotherday.Classroomsandtabletopsshouldbecleanedthoroughlyatleasteveryotherday.Sportshallsandsimilarareasrequiredailycleaning.
Inotherareasoftheschoolcleaningprogrammesshouldbecarriedoutasneeded.
Theuseofaddeddisinfectantsisonlynecessaryinspecialcases(diseasesnotifi-ableundertheGermanProtectionagainstInfectionsAct[Infektionsschutzgesetz]orinthecaseofcontaminationwithblood,faecesorvomit).Disinfectantclean-ingshouldnotbeundertakeninanyareaoftheschoolwithoutspecificcause,i.e.justtopreventinfectionsingeneral.
Sanitaryareasandwashroomsshouldbefittedoutsothatsufficientnumbersofwashbasinsareavailable.Soapdispensersandpapertowelsystemsshouldprefer-ablybeinstalledbythewashbasins.
Theproductionanduseofcleaningplansistoberecommended.Inrelationtotheseitisadvisabletosetoutthecleaning,ventilationandotherhygieneproce-durestobefollowedina„ComprehensiveHygienePlan”.
What must be cleaned in school buildings, and how often?
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A-3 Ventilation requirements
Themostimportantfunctionofventilationistorenewtheindoorairbyextractingimpuritiesintheformofgasanddustandthemetabolicprod-uctsfromhumans(odours,carbondioxide,watervapour)andtosupplyfreshairfromoutside.Inadditiontherearephysiologicalrequirements:achievingthemostcomfortablepossibleairtemperatureandhumidityintheroom,andachievingthermalbalance.
Untilnow,becauseoftheprevailingclimateinGermany,schoolbuildingshavegenerallybeendesignedandbuiltinsuchawaythatnaturalor“freshair”ventilationthroughwindowsshouldsuffice.However,inunfavour-ablelocations(e.g.considerablenoisepollutionfromthevicinityorhighairpollution)theinstallationofventilationsystemsmaybecomenecessary.Inadditionspecialextractionsystemsarerequiredforlaboratorieswhereexperimentsproducinghighlevelsofsmokearecarriedout.
Whenusingventilationviawindowsorairventsinexternalwallsitisim-portanttoreducetheimpactofpossiblehighnoiselevelsfromoutside(e.g.trafficnoise,aircraftnoise)onclassrooms.Theinstallationofhighlysound-absorbentventilatingwindowsorsound-insulatedventilationductscanbenecessaryinthiscase.
Topreventtheroomsfromoverheatingthroughsolarirradiance,windows,fixedglazingandskylightsshouldallnotbelargerthannecessaryforap-propriatedaylightingwithoutglare.Wheretheproportionofglassinthefaçadeexceeds50%,asisusualinschoolconstruction,allfaçades,withtheexceptionofthosefacingduenorth,requiresunshading.Fixedsunshadingdeviceshavethedisadvantageofreducingincomingdaylight.Southerlyas-pectsare,however,easiertofitwitheffectivesun-protectiondevices.Thesedevicesmustnotimpairthewindowventilationandshouldnotencouragetheinflowofwarmairrisinguptheoutsidewall.
Thecriterionfortherenewalofairinaroomistheair-changenumber.Thisisthequotientfromthevolumeofthesupplyofexchangedairintotheroomandthevolumeoftheroom.Itisdefinedasadimensionlesssizeperunittime(mostlyonehour).Anair-changenumberof1/h(“oneperhour”)meansthat(arithmetically)theentirevolumeofairinaroomiscompletelyreplacedinonehour.Adistinctionismadebetweennaturalairexchange,whichoccursasaresultofwindpressuredifferenceandthermallift,andmechanicalairexchangebymeansofventilationdevices.Withnaturalven-tilationthroughwide-openwindowstheair-changerateisaround10–20/h.
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Themorepollutedtheindoorairiswithcarbondioxide(CO2)andother
substances(cf.SectionsB-1toB-4),thegreaterbecomestheairexchangerequired.Withnormalclasssizesseveralchangesofairperhourarere-quiredfortheclassroom,inordertoextractenoughofthecarbondioxideproducedbythepupilsexhalingfromtheairintheroom.Thenecessaryairexchangeofaround25to30m3/hperpersoncannotbeachievedthroughnaturalventilationwithclosedwindows(knownaswindowgapventila-tion),butonlybyregularlyopeningthewindowswideforshortperiods(“intensiveventilation”foratleast5,preferablyupto10minutes).Evenmoreeffective(ifpossible)iscross-ventilationviawindowsoppositeeachother.Thereforetheroommustreallybeairedineverybreakbetweenlessonsand–withdoublelessonsorlargeclasses–duringlessonsaswell.(Ifthisisnecessary,thepupilsshouldleavetheroomsforsafetyreasonsdur-ingthistime.)Itisalsorecommendedthatintensiveventilationbecarriedoutbrieflyonceortwiceduringthelesson.
Basicallyusingthewindows.Todothisallwindowsinteachingareasshouldbeopenedwide(intensiveventilation,cross-ventilation)beforeschoolstartsandatleastduringeverybreak(specificallyincludingthefiveminutebreaks,whenthepupilsnormallystayintheroom!)forthewholedurationofthebreak.Ventila-tionbytiltingthewindowsislargelyineffective,ashardlyanyairisreplacedinthisway.
In the winter months heat inevitably escapes during ventilation. To minimiseenergy loss theradiatorvents shouldbeclosedduringventilation.Alternative-lyautomaticventswithwindowcontact switchescanbe installed.Thereserve capacityoftheheatgenerationshouldpermitswiftreheating.
The reservecapacityof theheating systemmustallow the rooms towarmupagainquicklyafterventilation–asotherwiseventilationwouldnotreallybecon-sideredacceptablebytheusersofrooms.
Ifmanualventilationwithwindowsisnotadequatetocreateormaintainhygieni-callyidealairqualityduringlessonsaswell,mechanicalventilationoptionscanbeinstalledtoensuresufficientairreplacementevenwiththewindowsclosed.Highlevelsofnoiseandotheremissionsoutsidecanalsomakemechanicalven-tilationsystemsnecessary.Ifsystemsofthissortareinstalled,regularservicingmustbeguaranteedonhygienegrounds.
How should the rooms be aired?
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A-4 Requirements for and cleaning of school swimming pools
Swimmingisextremelyvaluableinpromotinggoodhealth.Itisalsopar-ticularlyimportantinP.E.lessons.Someschoolshavetheirownswimmingpools.Swimmingishealthy,butcanalsocausehygieneproblems.Everyswimmerreleasesonaverage2.3to2.6billiongerms,possiblyincludingpathogenicmicro-organismssuchasstaphylococcus aureus,streptococcus pyogenes, salmonella spec.aswellaspathogenicviruses,intothewater.
Thereforeitisessentialtoensurethatnohealthrisksareposedbythewa-terinswimmingandbathingpools.TheProtectionagainstInfectionsAct(Article37)providesthelegalfoundationforthis:“Waterincommercially-runswimmingorbathingpools,publicbathsandothernotexclusivelypri-vatelyusedfacilitiesmustbesuchthatinusingitthereshouldbenoneedforconcernsoverharmtohumanhealth,especiallythroughpathogens”.
Inordereffectivelytopreventthetransferenceofpathogens,disinfectionofthewaterinthepoolisessential.Chlorinehasforalongtimeprovedvaluableasaneffectivedisinfectantonaccountofitsrapidandlong-lastingmicrobiocidalaction.Chlorinegasorhypochloritecompounds(DIN19643)areused.Insomepoolsbromineisalsoemployed,againbecauseofitsmicrobiocidaleffect.However,itismoredifficultforpooloperatorsandhealthagenciestomonitorthistypeofdisinfectionproperly,sincewiththeDPDmethodnormallyusedformonitoringitisimpossibletodistinguishbetweenfreeandboundbromine.ForthatreasonbromineisnotincludedasadisinfectantintheFederalEnvironmentAgency’srecommendation“Hygienerequirementsatpoolsandtheirsupervision”(Bundesgesundheits-bl-Gesundheitsforsch-Gesundheitsschutz9,2006).Itshouldbenotedwhenusingchlorineandbrominethatbothsubstancescauseirritation.Further-more,becauseofthereactionofchlorineorbrominewithwaterborneorganicsubstances,whicharemainlybroughtintothepoolwaterbyswim-mers(e.g.organiccompoundsfromurine,sweat,mucus,hair,flakesofskin,cosmetics),butwhicharealsotosomeextentalreadypresentinthewaterused(e.g.humicsubstances)hazardousdisinfectionby-products(DBPs)canbeproduced.ThebestknownoftheorganicDBPsarethetrihalogenmethanes(THMs).Theyhaveanindicatorfunctioninrelationtothehealthevaluationofpollutioninswimmingpoolwater.THMsalsoentertheairinindoorpoolsfromthespray.AirpollutionbyTHMscanbereducedbyeffec-tiveventilation.
RegardingtheassessmentoforganicDBPs,thereistodateinthefieldofswimmingpoolwateronlyacumulativevalueof0.02mg/lforTHMsinDIN
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19643,whichisbasedontechnologicalfeasibility.Inevaluatinghealthrisksarisingfromswimmingandbathingpoolwateritshouldbenotedthattworisksshouldbeweighedupagainsteachother,beingthemicrobiologicalandthetoxicological,wherebythemicrobiologicalshouldbeclassifiedasmorerelevantoverall.
Centraltoswimmingpoolwatertreatmentistheflocculation,filtrationandthechlorinationofthewater(DIN19643).Sometimesactivatedcarbonad-sorptionorozoningprecedesorfollowsflocculation.ExperiencesshowthatitistheflocculationandfiltrationprocessesthatarecarriedoutincorrectlyandthattherequirementsofDIN19643arenotmet.Thisalsoappliespar-ticularlytotheregularcleaningoffiltersthatisnecessary.
Incorrectwatertreatmentcanleadtopollutionofthepoolwaterwithpseudomonas aeruginosa (especiallyfollowingfiltercontamination)andtolegionella.Thereisanespeciallyhighriskofinfectioniftheshowersarecontaminatedwithlegionellabecausethehotwatersystemsaresetatalowtemperature.Schoolswhichoperateaswimmingpoolshouldincludetheservicingandcleaningofthepoolintheoverallhygieneplan.Inac-cordancewithDIN19643,specificmeasurestobeundertakeninthepoolregardingpoolwatertreatment,showersandcleaninganddisinfectionproceduresshouldbelaiddowninthehygieneplan.Theschoolshouldensurethatthestaffresponsibleforthepoolmachinerytakepartinregulartraininganddevelopmentinthisfield.TherecommendationsoftheFed-eralEnvironmentAgency’sSwimmingPoolWaterCommission(seeBun-desgesundheitsbl-Gesundheitsforsch-Gesundheitsschutz9,2006)andfurtherhygienerecommendations(e.g.poolhygieneplans)shouldalsobetakenintoaccounthere.
InafurtherrecommendationfromtheSwimmingPoolWaterCommission(Bundesgesundheitsbl1997)specialinstructionsforpreventingthecontrac-tionofwartsaftervisitingswimmingpoolsarebeingissued.Wartsarecausedbyviruses.Moreover,therearevarioustypesofwarts,whichcanoccurmostcommonlyonthebacksandpalmsofthehands,thefingers,andonthesolesofthefeet(verrucas).Molluscumcontagiosum(MC)causeslumpsfrompinhead-sizetothesizeofapea,withasmoothandoften
Thetreatmentofswimmingpoolwaterisatechnicallycomplexprocedurethatrequiresahighlevelofexpertiseinpooltechnologyonthepartoftherelevantoperators. In the case of school-run swimming pools this is often only barelyachievable,astheyhavenospecialiststaff.Thetechnicaloperationofthesepoolsisundertakenbytheschoolcaretakersorbylocalauthorityemployees,whomustbeexperiencedindealingwithmaintenanceandpoolmachinery.
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shinysurface,whichsometimeshasadipinthemiddle.Theycanoccuranywhereonthebody.MCistransmittedthroughdirecthumancontact(whenplaying,takingpartinsport,etc.),whereasnormalwartsaremainlytransmittedindirectly,throughcontactwithmaterialorobjectscontainingthevirus.
Infectiondoesnottakeplaceviathewater.
ChildrenandyoungpeopleshouldbeinformedaboutthecontagiousnessofwartsbyP.E.teachersorotherresponsiblepeople.Indoingthis,thefol-lowingpointsshouldbeemphasised:
Youshouldavoidsharingtheuseoftowels,massageoil,skinlotions,etc.amongseveralpeople.
Youshouldrefrainfromgoingbarefootinswimmingpoolsifyoualreadyhavewartsorverrucas.
Avisittothedoctorisrecommendedifyouhavewarts.
Whenuseoftheswimmingpoolisover,thesurfaceswalkedonwithbarefeetshouldbedisinfectedwithanactivevirucideinaccordancewiththelistofdisinfectantsfromtheGermanAssociationforHygieneandMicrobiologyortheRobertKochInstitute.Thescrubbingandwashingprocedureshouldbeusedforthis.Sprayingwithdisinfectantisnotsufficient,asflakesofskinarenotremovedeffectivelybythis.
A-5 Minor building works and renovations
Afterminorbuildingworks,maintenanceandrenovationstherearealwayscomplaintsfromteachers,pupilsandparentsaboutpoorindoorairquality.Problemswithindooraircanbelargelyavoidedwhenminorbuildingandrenovationprojectsarecarriedoutcorrectly.
Therearefouraspectstobeconsideredinrelationtoairhygienepriortobuildingandrenovationwork,inordertominimiselateremissions:
Choiceofmaterials
Quantityofmaterials
Monitoringoftheprogressandcompletionofthework
Coordinatingandmonitoringthetimeframe.
Buildingproductsandothermaterialsreleasevolatileorganiccompounds(VOCs)intotheairintheroom(cf.SectionB-2).Thiscanhavenegativeimpactsontheusersoftheroom.Theextentofthesedetrimentaleffects
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dependsonthetypeandintensityaswellasthedurationoftheVOCemis-sions.Particularlythosematerialstobeusedoverlargeareasintherooms,suchassurfacecoatings,bondings,andfloorcoveringsshouldbechosensothattheminimumofemissionsareproducedafterinstallationandduringlateruse.
InthecontextoftheseGuidelinesitisnotpossibletogivealistofbuildingproductsanddecoratingmaterialstoberecommendedonahygienebasis,asthereisavastarrayofproductsonthemarket,whichissubjecttore-gionalvariationandwillchangeovertime.IntheSafetyDataSheetsfortheproductsthemanufacturersandsuppliersmustlist,amongstotherthings,substancessubjecttolabellingregulations.InstructionsforuseandfurtherproductinformationcanbefoundintheTechnicalDataSheets.Forthemostpartthereisinsufficientinformationonemissionsbehaviourinthesedatasheets.TheIndoorAirHygieneCommissionrecommendsgivingprior-itytomanufacturersandsuppliersofbuildingproductsandothermaterialswhorespondtoconsumerdemandformoredetailedinformation.
ProductsmarkedwiththeBlueAngelecolabel“lowinemissions”or“lowinhazardoussubstances”producelowlevelsofemissionsandshouldprefer-ablybeused.Theleaflet“UmweltzeichenfürBauprodukte.Bauproduktegezieltauswählen”[Ecolabelsforbuildingproducts.Howtochoosetherightbuildingproducts]offersadviceonproductselection.Thisisavail-ableatwww.apug.nrw.de/pdf/Bauprodukte.pdf.Unfortunately,productsbearingtheBlueAngelandotherenvironmentallabelsarenotyetavailableforallareasofapplication.
Odourspresentamajorprobleminthechoiceofbuildingmaterials.Manybuildingproductsarenotodour-free,especiallywhentheyaredeliveredfreshfromthefactory.Theseodourscanthenpersistinthefirstfewmonthsafterinstallationandleadtounpleasanteffectsfortheusersofthespace.Atpresentitisnotpossibletogaugehowmuchodourpollutionarisesfrom
Beforestartingminorbuildingworks,maintenanceandrenovationsanoverviewof the type and amount of substances contained in materials needed for thebuildingandrenovationworkshouldbeavailabletotheappropriateoffice.Ini-tialinformationonthiscanbefoundintheTechnicalDataSheetsandtheSafetyDataSheets.Furtherdetailscanbeobtainedfromthemanufacturerorsupplier.Somemanufacturershavecommissionedstudiesintotheemissionsbehaviouroftheirproductsandcanprovideinformationonit.ProductswiththeBlueAngelecolabelshouldpreferablybeused.
What should be considered when choosing materials?
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products,evenbyonlychoosingthebestmaterials,forexamplethosetestedinaccordancewiththeAgBB[CommitteefortheHealthEvaluationofBuild-ingProducts]scheme(fortheAgBBschemeseeSectionC-1)andapprovedbytheDeutschesInstitutfürBautechnik[GermanInstituteforConstructionEngineering].Thetestconditionscurrentlyonlyincludeananalysisofvola-tileorganiccompounds(VOCs,seeSectionB-2)andsemi-volatilecompounds(SVOCs,cf.SectionB-4).Variousstudieshaveshownthatthereisnocor-relationbetweenVOCemissionsandodouremissions.Infutureodoursarealsotobeincludedinevaluationsbasedonthescheme.Therehavebeeninitialexperimentswithaprocessfortheodourevaluationofconstructionproductsonthebasisofmeasurementstakenintestchambersformeasur-ingemissions(cf.Furtherreading“Bauprodukte:SchadstoffeundGerüchebestimmenundvermeiden”[Buildingmaterials:identifyingandavoidinghazardoussubstancesandodours]inSectionIII).Thisprocess,whichisbasedontheevaluationofodourintensitybyatrainedpanel(agroupofpeoplespeciallytrainedtorecogniseodours)withtheaidofastandardofcompari-son,hasproveditssuitabilityandgoodreproducibilityinaroundrobintest.Asithasnowgainedgeneralacceptancethisprocessiscurrentlyundergo-inginternationalstandardisation(ISOTC146/SC6).
Theproductsandmaterialsselectedandusedshouldnotonlybelowinemissions,butshouldalsobeasdurableaspossible.Everyextensionintheperiodofusepostponesmorebuildingorrenovationworkwiththepoten-tialtoreduceindoorairquality.
Theselectionanduseoflow-emissionconstructionproductsisonecriterionforavoidinghazardousemissions,whiletheotherison-sitemonitoringwhethertheseproductsareindeedbeinginstalledintheschoolbuildingintheproperway.Propersupervisionoftheworkbyaprojectmanagerorcomparableexpertfamiliarwiththeindoorairhygienerequirementsisthereforetobestronglyadvised.
Inthecaseoflayeredconstructionoffloorsandotherlargesurfacescareshouldbetakentocarryouttheseparatestagesinsuchawaythatthesolventsandotherauxiliaryvolatilematerialsusedevaporateasfullyaspossiblebeforethenextlayerisapplied(seemanufacturer’sinstructions).Particularlyinthecaseofabsorbentproductsandproductscoveringlargeareas,orthecorrespondingsubsurfaces,itisessentialtoensurethatnooronlysmallquantitiesofvolatileorganiccompoundsareingested(e.g.byapplyingasuitablebarrierlayer)fromsubsequentstagesofworkandduringlatercleaningprocedures.
Theformationofsubstancedepositsbetweenlayersshouldbeavoidedifpossible.Forthesamereasonproductscontainingvolatilesubstancesshouldnotbeallowedtopenetrategaps,cracksandcavitiesinlargequantities.
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Careshouldalsobetakenduringrenovationstoensurethattheexistingsubsurfaceandresiduesofoldmaterialonitdonotreacttothenewprod-uctsinawaythatcouldforexampleleadtoodourpollution.Theapplica-tionofasuitablebarrierlayercanpreventreactions.
TheemissionofVOCsandSVOCsfromconstructionproductsanddecoratingmaterialscanbeconsiderablyrestricted,butnotcompletelyavoided.IndoorairisalmostalwaysadditionallycontaminatedbyVOCs(lessbySVOCs,whichreleasegasmoreslowly)immediatelyafterbuildingandrenovationwork.Forthisreasonacertainlengthoftimeshouldbefactoredin(thiscantakefromonetoseveralweeks,dependingontheextentandtypeofreno-vationwork)fortheVOCstoescapebeforeusingtheroomsagain.Inschoolsitisagoodideaforminorbuildingworksandrenovationstobescheduledforthebeginningoftheschoolholidays,sothatmostofthecomponentshavealreadybeenreleasedfromthematerialsbeforetheroomisusedagain.Whiletheoffgassingofthesubstancesistakingplacetheremustbeintensiveventilation.
Ifhotwaterpipesandradiatorshavebeennewlypainted,itisstronglyrecommendedtoruntheheatingsystembrieflywhenthepaintisdrywithnobodyintheroom.Thiswillallowcompoundsthatonlyoccurinthepaintlayerathighertemperaturesandoftengenerateunpleasantodoursandirritationstobereleasedfromthepaintlayerasfaraspossibleingoodtimebeforethelaterusephase.
Oncetheconstructionandrenovationworkiscompletetheentirebuildingshouldbeintensivelycleaned.Cleaningwithwaterandthemostthoroughpossibleremovalofalldustdeposits,whichmaylateractas“long-termstor-age”forsemi-volatileorganiccompounds(cf.SectionB-4)emittedduringtherenovation,isstronglyadvised.
Check whether the products selected are actually used in the project. Ifnecessary, checkwhether thematerialsdeliveredcomplywithallqualityrequirements(includingemissionsbehaviour).
Checkwhetherthematerialsselectedareunloadedproperlyandinsuffi-cienttime,ifthisisspecifiedinthechoiceofmaterial.
Checkwhethertheworkinginstructionsandadvicefromthemanufacturerarebeingfollowed.
Checkwhetheradequateventilationandevaporationtimeisbeingallowedwhenlayingandfixingmaterials.
What hygiene implications can and should an on-site project manager consider during renovation work?
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A-6 Workshops, laboratories and home economics practical areas
Workshops,laboratoriesandhomeeconomicspracticalareascountasspecialteachingareasusedonlyforthesepurposes.Therecanbeparticu-larproblemshere,forexamplewhencarryingoutexperimentsinvolvingsmokeproduction,whichdonotoccurinnormalclassrooms,oratanyratenotinthisform.Extensiveregulationsexistfortheseareas,includingintheOrdinanceonHazardousSubstancesandtheGermanFoodLaw,whichwillnotbediscussedfurtherintheseGuidelines.Inthefollowingsectionpos-siblepollutionsourcesandexistingregulationswillbereferredtobriefly.
Workshops
Ventilationrequirementsforschoolworkshopsarelaiddowninthe“RegelnfürSicherheitundGesundheitsschutzbeimUmgangmitGefahrstoffenimUnterricht”[Healthandsafetyrulesfordealingwithhazardoussubstancesinlessons](GUV19.16edition.January1998,clause5.2).Inaccordancewiththeseadequateventilationmeasuresarerequired,amongstotherthings,whenworkingintechnicalsubjectsandinartlessons,ifhazardoussub-stancesarebeingusedorcouldbereleasedintotheairintheroomduringthelesson.Whenweldingistakingplaceair-conditioningmeasuresarenec-essary,whilefornormalsolderingnaturalventilationisgenerallysufficient.Inthecaseofwoodworklow-dustworkingconditionsmustbecreatedintheworkshops.Thiscanbebestachievedbyensuringthat:
thedailyexposureremainsbelowhalfanhourperschooldayandthewoodworkmachineryisonlyusedforafewdaysayear.
thesawdustfromstandardwoodworkingmachineryisvacuumedupatthepointofproduction.
thewoodworkingmachineryisfittedwithdustcollectingunitsandcertifieddustextractors.
Laboratories
Areasusedforsciencelessons,suchaschemistrylaboratories,mustbeequippedwithatleastonefumecupboardinaccordancewithGUV19.16.Thefumecupboardsmustensurethatgases,vapours,smoke,fumesanddustparticlescannotescapeintotheclassroomfrominsidethecupboardinhazardousconcentrationsorquantities.Adangerousexplosiveatmospheremustnotbecreatedinsidethefumecupboard.Aslidingfrontpanelmustbeclosedtoprotectpeople,incasehazardoussubstancessplashorglassshatters.
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Home economics practical areas
KitchenscomeundertheBerufsgenossenschaftlicheRegel[professionalassociationrule](BGR111;previouslyZH1/37)“RegelnfürSicherheitundGesundheitsschutzbeiderArbeitinKüchen”[Healthandsafetyrulesforworkinginkitchens].Homeeconomicsteachingroomsarealsolistedasareastowhichitapplies,buttherulesshouldbeappliedinsenseonly,bearinginmindtheschoolsituation.Accordingtotherules,duringwork-ingtimesairandroomtemperatureconducivetohealthmustbeprovided,takingintoaccounttheworkbeingundertakenandthephysicaldemandsoftheworkers.Forequipmentlikelytoproduceincreasedvapourandcook-ingfumes,e.g.kettles,tiltingfryingpans,anddeep-fatfryers,anextractorhoodisrequired.Duringboiling,fryingandbakingtinyparticlescanbereleased;todatetherehasbeenlittleornoresearchintotheirhygienicimportance.Tobeonthesafeside,cookingprocessesofthissortshouldbecarriedoutundertheextractorhood.Largequantitiesofnitrousoxidecanarisethroughtheuseofgasstovesforcooking.Insuchcasesgoodventila-tionshouldbeprovidedinadditiontotheextractorhood.
Blowcleaningandsweepingraisessawdustresiduesandisabsolutelyprohibited.Sawdustmustalwaysbevacuumedupbymachine.
Whenworkinginspecialisedteachingareasparticularcareisneededforthepro-tectionofpupilsandteachers.Thecurrentregulationsmustalwaysbeobserved.Fumecupboardsshouldbeinstalledinsufficientnumbersandmustfunctionper-fectly.Regularmaintenanceandinspectionsofthecupboardsisessential.Whenusinghazardoussubstanceschecksmustbemadetoseewhetheralternativesub-stances,preparationsorproductswithalowerorpreferablynohealthriskcanbesubstituted.Contactwithcarcinogenic, suspectedcarcinogenic,mutagenicandreprotoxicsubstances(CMRsubstances)shouldnottakeplaceinanyschoolsub-ject.Theexceptionsareonlyteachingexperimentsinwhichtheintentionistostudythereactionofsomesubstanceswithothers.Thissortofexperimentmayonlybeconductedbytrainedteachingstaff(asademonstrationexperiment)andmusttakeplaceinthefumecupboard.Dependingontheexperimentadditionalindividualsafetymeasuresmayneedtobetaken(thewearingoffacemasks,pro-tectiveglassesandgloves,labcoats).
What should generally be taken into account when working in workshops, laboratories and home economics kitchens?
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A-7 Copiers, printers and PCs
Recentlytherehasbeenanincreaseinpressreportsthatindoorairpol-lutionfromvolatileorganiccompounds(styrene,benzeneetc.)aswellasfromsuspendedparticulatematterandultra-fineparticlescanbereleasedbycopiersandprinters.
TheFederalEnvironmentAgencyandtheUniversityofGiessenalsoestab-lishedina2007studythatultra-fineandfineparticlesareemittedwhenlaserprintersareused.Theresultsareavailableat:http://www.umweltdaten.de/publikationen/fpdf-l/3016.pdf andathttp://www.bfr.bund.de/cd/8644). VOCs are also released.
Theexactcompositionoftheparticlesreleasedbyprintersduringoperationisasyetunclear.ThelatestresearchattheUniversityofGiessenandotherinstitutionshasshownthattonerparticlesmakeuponlyasmallfractionoftheparticleemissions.Furtherstudiesareneededforclarification.
Owingtotheelectrophotographicprocess,ozonecanbeproducedduringtheoperationofcopiersandlaserprinters.Theamountsofozonereleasedaredependentonthetechnicalpropertiesofthemachine,thelengthofoperationandtheconditionofthemachines,aswellasthesizeoftheroominwhichtheyareinstalled.However,significantconcentrationsofozonehardlyoccuranylongerwithmodernmachines.Newermachines(sinceabout1992)arefittedwitheffectiveozoneadsorbers.
Thereisoftendiscussioninthepublicdomain,inrelationtoofficemachin-ery,abouttheuseandpossibleemissionfromfireretardants.Forfiresafetyreasonsplasticsusedinelectronicsforcasings,circuitboardsandcableinsulationaretreatedwithfireretardants(particularlyhalogenatedorganiccompounds).Halogenatedfireretardantsmaynotbepresentinmachinerywithanecolabel.
CopiersandlaserprinterscanemitsmallquantitiesofVOCsandparticlesduringoperation.Thereisapossibilityofbrieflycontaminatingtheairintheroomwhenthetonercartridgesarechanged.Forthisreasontonercartridgesshouldonlybechangedbydesignatedstaffandwithgreatcare.Larger,frequentlyusedprinters(“centralprinters”)andcopiersshouldbehousedinseparateroomswiththeirownventilationsystem.Whenpurchasingaprinteronlymachineswith theecolabel(RAL-UZ122)shouldbeconsidered.AdviceonpurchasingandoperatingprintersisalsocontainedintheFederalInstituteforOccupationalSafetyandHealth’srecom-mendations (available at: www.baua.de/nn_5846/de/Publikationen/Faltblaetter/F44.html?__nnn=true)
Are concentrations of substances harmful to health emitted by copiers, laser printers and other electronic equipment?
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PART B: Contaminants in the indoor air in schools
Inthefollowingsectionsthesourcesofindooraircontaminationwillfirstbeexaminedandtheirhygienicimportanceinsideschoolssubsequentlydescribed.
B-1 Inorganic gases Table1givesanoverviewofimportantsourcesofinorganicgasesinindoor
air.Withtheexceptionofozonetheseinorganicgasesareproducedbyburningfossilfuels.Carbondioxideisalsoreleasedthroughbreathing.
Carbon dioxide(CO2)arisesthroughburningorganicmaterialsandisreleased
throughbreathing.Thecompoundisofparticularimportanceinschoolclassrooms,ashere–asinotherenclosedareasthataredenselyoccupied–alargenumberofpeoplecometogetherinarestrictedspace.Aslongas150yearsagothehygienistMaxvonPettenkoferdrewattentiontothefactsof“bad”airwhenalongtimewasspentinlivingspacesandeducationalestablishmentsandidentifiedcarbondioxideasanimportantindicatorinassessingindoorairquality.ForalongtimethePettenkoferNumber0.1volumepercent(=1000partspermillion(ppm))wasregardedastheevaluationyardstickinindoorspaces.BycomparisontheCO
2contentof
outsideairisaround350ppm(intownsinsomeplacesevenuptoaround500ppm).
TheadhocworkinggroupoftheIndoorAirHygieneCommissionandtheWorkingGroupoftheSupremeHealthAuthoritiesoftheFederalStates(IRK/AOLGadhocworkinggroup)hasproducedanevaluationforcarbondioxideinindoorair(Table2)(Ad-hocAGIRK/AOLG,2008:Gesundheitli-cheBewertungvonKohlendioxidinderInnenraumluft[Healthevaluation
Table 1: Sources of relevant inorganic gases inside schools
Compound Source
Carbon dioxide (CO2) People,nakedflames
Carbon monoxide (CO)Experiments with incomplete combustion of organicmaterials,homeeconomicskitchens,outsideair
Nitrogen dioxide (NO2)
Homeeconomicskitchens (gascooker),Bunsenburn-ers,outsideair
Ozone (O3) Outsideair(summer),copiers,laserprinters
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ofcarbondioxideinindoorair],Bundesgesundheitsbl-Gesundheitsforsch-Gesundheitsschutz(inpress)).Accordingtothis,guidevaluesforcarbondioxideconcentrationsinindoorairarelaiddown,whicharetobeseenassnapshotvaluespertainingtotheconcentrationatagivenmomentintime.Itisdividedinto“hygienicallyinsignificant”(CO
2<1000ppm),
“hygienicallyevident”(CO21000–2000)and“hygienicallyunacceptable”
(CO2>2000ppm).IfaCO
2valueof1000ppmisexceededtheroomshould
beaired,andif2000ppmisexceededitmustbeaired.Inbothcasestheaimshouldbetoremainbelow1000ppm.Ifthesituationcannotbeim-provedinthelongtermbyairingalone,air-conditioningmeasuresshouldbeemployedorthenumberofpupilsintheclassroomshouldbereduced.
Table 2. Guide values for carbon dioxide concentration in indoor air (Ad hoc working group 2008)
Co2 concentration [ ppm] Hygiene rating Recommendation
<1000Hygienicallyinsignificant
Nofurthermeasures
1000–2000Hygienicallyevident
Intensifyventilationmeasures(increasevolumeofairflowfromoutsideorairexchange).
Checkandimproveventilationprocedures
>2000Hygienicallyunacceptable
Checkventilationpossibilitiesandifnecessarycheckexten-sivemeasures
Theconcentrationofcarbondioxideinindoorairdependsonthenumber,lengthoftimespentandactivityofthepeoplepresentaswellasontheconstructiondetails(volumeoftheroom,airexchangenumber,etc.).Al-thoughtheproblemofcarbondioxideinroomscontainingalargenumberofpeoplehaslongbeenknown,todatenoconvincingsolutionshavebeenfoundforschools.Atthesametimetherearenoclearregulationsregard-ingresponsibility,especiallyinthewintermonths,abouthow,whenandbywhomtheclassroomwindowsshouldbeopened.Asistobeexpected,thisresultsinhightoveryhighCO
2values(3000ppmandabove),butalsoin
anincreaseinotherindoorpollutantsandwatervapour.ThereisanurgentneedtodevelopideasformeetingtheguidevaluesgiveninTable2.
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Toassistschoolsonecouldenvisageasensor-driventrafficlightwhichchangesfromgreentoambertoredifspecificCO
2valuesareexceededand
indicatestheneedforactioninaccordancewithTable2.Themeasuringin-tervalforthesensor-operatedsystemshouldalsobeverycarefullyselected,inordertopreventthereadingfromchangingconstantlyfromonetoanotherduringoperationandthusmakingtheactiontobetakenunwork-able.Ameasuringintervalofatleast2minutesisrecommended.
Ifnaturalairexchangeviaopenwindowsisimpossible,air-conditioningmeasuresmustbeintroducedinordertokeeptheCO
2concentrationsata
lowlevel.
Until2005aCO2valueof0.15vol.-%(=1500ppm)inaccordancewith
DIN1946Part2appliedastheguidelinehygienevalueinGermanyinschoolswithair-conditioninginstallations.InJuly2005DIN1946-2wasreplacedbyEN13779,whichwasamendedinSeptember2007.ThisENcontainsrecommendationsforplanningandinstallingair-conditioningsystemsinallnon-residentialbuildingsintendedforhumanoccupation.Indoorairissubdividedintofourqualitylevels(IndoorAir1to4).Differ-entventilationratesperpersonorperm2floorareaarederivedfromthesequalitylevels
Wearenowundoubtedlyonthethresholdofacertainparadigmshiftinthoughtand action. The current situation in many schools shows that in many placestheCO
2problemcannolongerbebroughtundercontrolthroughrequestsfor
regularandintensiveventilationalone.Air-conditioningmeasuresthenbecomeessential in order to achievepermanenthighquality airwith a lowCO2 con-centrationwithoutdependingonhumanintervention.Regularservicingandin-spectionsofthesystemarenecessary,sothatthisdoesnotitselfleadtohygieneproblems.
Fresh air through windows or ventilaion systems in schools?
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Carbon monoxide(CO)isreleasedduringtheincompletecombustionoffossilfuels.Onbusyroads,especiallyinconurbations,italsopenetratesindoorspaceswiththeoutsideairduringventilation.Tobaccosmokerepresentsanotherconsiderablesourceofemissions.Preventingtheoccurrenceofcarbonmonoxideisyetanotherreasontoemphasisethegeneralsmok-ingbaninschools.COcanalsoentertheindoorairthroughusinggasforcookinginhomeeconomicskitchens–however,onlywhereairextractionisinadequate.Carbonmonoxideimpairsthetransportofoxygenwithhae-moglobin.However,theconcentrationsnecessaryforthisarenotnormallytobeexpectedinschools.
Nitrogen oxides(NOx=sumofnitricoxide(NO)andnitrogendioxide(NO2))
enterindoorairmainlythroughburninggas(Bunsenburnersinlaborato-ries,gascookersinhomeeconomicsrooms),apartfromcominginfromoutside.Thiscanbelargelyavoidedbysuitableairextractionwhencookingwithgasinhomeeconomicsrooms.Short-livedraisedconcentrationsofNO
2inindooraircanalsoarisefromtheuseofoilinlampsorlargernum-
bersofcandles.Withprolongedhighlevelsofexposure,nitrogendioxidepromotestheonsetofdiseasesoftherespiratorytracts.
Table 3. Classification of indoor air quality in accordance with DIN EN 13779: 2007-09. The table contains the regulations from DIN EN 13779 in columns 1 to 3. Column 3 shows the relation of the CO
2 concentration in indoor air to the total CO
2 concentration. Column 4 indicates the absolute CO
2
concentrations in indoor air for an outside air CO2 concentration of for example 400 ppm.
Category Description Increase in CO2
concentration compared with out-side air [ppm]
Absolute CO2
concentration in indoor air [ppm]
Ventilation rate/ outside air flow volume [l/s/person] ([m3/h/person])
IDA 1Highindoorairquality
≤400 ≤800>15(>54)
IDA 2Mediumairquality
>400–600 >800–1000>10–15(>36–54)
IDA 3Moderateindoorairquality
>600–1000 >1000–1400>6–10(>22–36)
IDA 4Poorindoorairquality
>1000 >1400<6(<22)
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Ozone(O3)canbeemittedintoindoorairinschoolsthroughtheuseofcopi-
ersandlaserprinters,oringeneralfrommachineswhichhavesourcesofUVrays(cf.SectionA-7).Modernofficeequipmentgivesoffsolittleozonethateveninsensitivepeoplebreathingdifficultiesandimpairmentsinlungfunctiondonotoccur.
Inhighsummerweatherconditionsozoneformedintheairoutsidealsoentersindoorspacesthroughventilation.Ingeneralozoneisquicklybro-kendownintheindoorenvironment.
B-2 Volatile organic compounds (VOCs)
Volatileorganiccompounds(VOCs)representagroupofairpollutantsubstancesthatpracticallyalwaysoccurinindoorair.VOCsarecharacter-isedasagroupofverydiversesubstancesbytheirboilingpointanddis-tinguishedfromtheveryvolatile,semi-volatileandnon-volatileorganiccompounds.Accordingtoconventionorganochemicalcompoundswithaboilingpointof50–100oCto240–260oCaredescribedasvolatileorganiccompounds(VOCs)(WHO1989).Inanalyticalpracticeorganiccompoundswhichcanbedeterminedintheelutionrangebetweenn-hexaneandn-hexadecanearedescribedasVOCs.Thesumofthevolatileorganiccompoundselutedbetweenn-hexaneandn-hexadecanearedesignatedTVOCs(totalvolatileorganiccompounds).Semi-volatileorganiccompounds(SVOCs)areorganiccompoundsthatlieintheretentionrangeaboven-hexadecaneuptoC
22,andveryvolatileorganiccompounds(VVOCs)those
thatappearbelown-hexane.Table4givesanoverviewofVOCsoftenrecordedinindoorspacesandtheirsources.
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Inparticular,thefollowingVOCsareimportantforindoorareasinschools:
Alkanes and alkenes
Alkanesarestraight-chainsaturatedcompounds(aliphates)whicharedistinguishedbythenumberofcarbonandhydrogenatomsinthemol-ecule.Afterrenovations,butalsoaftercleaningofclassrooms,thegroupofnonanetotetradecane(9and14carbonatomsrespectivelyinthemolecule;C-9andC-14,respectively)isfoundespeciallyfrequentlyintheindoorair.Inunfavourablecircumstanceslightheatingoiltankscanbecomesourcesofalkanesinthegroupbetweentetradecane(C-14)andoctadecane(C-18).Thisgroupofalkaneswithboilingpointstoover300oCissometimesalso
Table 4: VOCs often recorded in indoor spaces and their sources; 1) except formaldehyde, which belongs to the VVOC group
VOCs and VOC groups Sources
Alkanes, alkenes and cycloalkenes
Outdoorair,motorisedtraffic,fuels,solvents(solventnaphta)invarnishes,resinsandstainremovers
Aromatic compoundsVehicleemissions,cigarettesmoke,solvents,carpetbackside(e.g.Phenylcyclohexene),foamproducts
TerpenesWood,solvents,“odourimprovers”,fragranceadditivesz
NaphthalenesBitumentiles,taradhesives,tarredfelts,mothrepellent
AlcoholsCleaningproducts,solvents,sub-productsfrome.g.plasticizers
Aldehydes 1)
Kitchenvapour,disinfectants,alkydresinpaints,oilpaints,linoleumby-products,corkflooring,woodproducts
Ketonessolvents(e.g.Methylethylketone),metabolites,sealcoatedsurfaces
EstersSolvents,softeners,heatingcostsdistributor(methylbenzonate)
Glycol ethersSolventsinwatersolublepaintsandvarnishes,cleaningproducts
Halogenated compoundsDegreasing,solvents,drycleaning(tetrachloro-ethene),Tippex(1.1.1-trichloroethane),toiletblocks(p-dichlorobenzol)
Other compoundsBondingagents(phenol),disinfectants(cresols),sealingcompounds(butanonoxime)
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usedassolventsand,sincestrictlyspeakingitdoesnotbelongtotheVOCgroup,isonlymentionedforthesakeofcompleteness.Thisapplieslikewisetotheveryvolatilen-alkanes,suchasmethane(C-1)andbutane(C-4),whichareconstituentsofnaturalgasandarenotgenerallymeasuredwiththeusualindoorairanalysismethods.
Alkenes(olefins)areunsaturatedhydrocarboncompounds.Longstraight-chainolefincompoundsrepresentreagentsandby-products.Saturatedcy-clichydrocarbonssuchascyclohexaneandmethylcyclohexaneareusedassolventsinvarnishes,resinsandstainremoversintheindoorenvironment.
Aromatic compounds
Aromaticcompounds(arenes)arehydrocarboncompoundswithaclosedringstructure,inwhich,incontrasttosimplecycliccompounds,particularbondingpropertiesexistbetweenthecarbonatomsinthering.Inschoolspracticallytheonlysourceofbenzene,thebasicsubstanceinthearomaticgroupwith6carbonatoms,whichistoxicologicallyparticularlysignificantbecauseofitscarcinogeniceffect,istraffic-pollutedoutsideair(upto1%benzeneispermittedinfuel).
Inthepasttoluenewasfrequentlyusedasasolvent.Nowadayshigheraromaticcompoundswith8carbonatomsandmore(calledalkylarenes)areusedinplaceoftoluene.Theseoftenalsohaveanobviousodour.Thisisalsothecasewithstyrene,whichishoweverrarelyencounteredinschools.Polynucleararomatichydrocarbons(e.g.naphthalene,indenes)arealsogenerallyoflittlesignificanceintheindoorairinschools,exceptthatbitu-menandcoaltarproductswereusedinflooringconstruction,forexample(moisturestop,woodblockflooradhesive);compoundsofthatkindarethenreleasedintoindoorair.
Terpenes
TerpenesrepresentanimportantgroupofVOCs.Themonoterpeneslimonene,α-andβ-pineneandδ-3-carenearefrequentlyandincreasinglytobefoundinindoorspaces.Naturallyoccurringgasesfromwoodproducts,additionasfragranceanduseasa“natural”solventforvariousproducts(includingpaints,varnishesandwoodtreatments)aresubstantialroutesofentryintoindoorair.Terpenesarealsofoundincomparativelyhighconcentrationsinpreciselythosebuildingsandroomsconstructedorfittedaccordingtoenvironmentalprinciples,especiallyifwallsandceilingsarecladextensivelyinsolidpine.Variousterpenealcoholsandterpeneketones(e.g.geraniol,camphor)areintroducedintotheindoorairwithfragrances.
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Alcohols
Apartfromethanol(alsocalledethylalcohol),colloquiallyknownas“alco-hol”,thereareothercompoundsbelongingtothechemicalclassofalcoholswhicharetobefoundinindoorair.Lowalcoholssuchasethanolorpro-panol,isopropanolundisobutanoloccurinverymanyhouseholdproducts(e.g.cleaningagents,solvents,disinfectantsandcosmetics).Asaresultofhydrolyticcleavageamongstotherthings2-ethylhexanol,analcoholwhichoccasionallycontributestoodourproblemsinindoorspaces,canentertheindoorairfromsoftenersandplastics.
Glycols
Glycolethersaretechnicalsolventsinfrequentuse,especiallyinvarnishes,dyesandprintinginks,stampingink,wallpaints,water-basedenamelsandballpointpenpastes,andareregularlydetectedinindoorair,sincetheyareusedassubstitutesfortheclassicaliphaticandaromaticsolventsmentionedabove.EvenenamelsdisplayingtheBlueAngellabelmaycontainupto10%glycolcompounds,andglycolcompoundswithboilingpointsabove200oCareusedinso-calledsolvent-freecarpetadhesives.Glycolsandglycolethers(suchas2-buthoxyethanol,phenoxyethanolanddiethyleneglycolmonoethylether)arepolarcompoundswithboilingpointsabove120oC.Onaccountoftheirrelativelyhighboilingpointtheycanbeemittedfromsurfacesoverlongperiods(months).
Aldehydes
Incontrasttothehigheraldehydes,thesimplestrepresentativeofthissub-stancegroup,formaldehyde,doesnotbelongtotheVOCgroup,buttotheVVOCs,onaccountofitslowboilingpoint.Becauseofitswidedistributionanditsimportancewithregardtohygieneaseparatesectionisdevotedtoit(seeSectionB-3).
Ofthestraight-chainaldehydesn-hexanalinparticularoftenoccursinindoorair.Importantsourcesarealkydresinpaintsandvarnishes.
Inthecourseofdrying,interlacingandalsotheoxidativedegradationoftheoil-basedbinders,thealdehydesaresplitoffandreleased.Sincelino-leumalsocontainsoil-basedbinders,aldehydescanbegivenoffintothesurroundingairfrompoorlymaintainedlinoleumfloors(cf.SectionA-2).Benzaldehydeisfoundasafragrance(likebitteralmonds)inperfumeditems.
Furfuralisanaldehydewitharing-shaped(cyclic)molecularstructure,whichcanentertheindoorairifusedinpressedcorkproducts(e.g.floor
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tiles).Propanal(acrolein)isoneoftheunsaturatedaldehydeswithaparticu-larlypungentodour.Onewayinwhichthecompoundisproducedisinthethermaldecompositionoffats(cookingvapour).
Ketones
Butanone(methylethylketone–MEK)andhexanone(methylisobutylketone–MIBK)aresolventswithvarioususes,e.g.inall-purposeadhe-sives,andcanenterindoorairasthegluedriesout.Cyclohexanoneandacetophenoneareoccasionallygivenoffintotheindoorairfromsurfacecoatings.
Esters
Estersarefrequentlyusedsolvents:ethylacetate,butylacetateandisobutylacetatecanoccurinindoorair,particularlyafteralterationsandrenovationwork.Texanolisusedasanadditiveforvarnishes,woodfloorsealantsanddispersionpaints(latexpaints),andink-jetprinterinks,toimprovethefilmformation.Mixturesofestersandalcoholsarecomingontothemarketinincreasingquantities.Water-basedpaintscancontainsuchmixturesandgiveoffthecorrespondingcompoundsintotheindoorair.EsterTXIB(texa-nolisobutyrate)isnowusedasasubstituteforsofteners(cf.SectionB-4).
Halogenated organic compounds
Overthelasttenyears,concentrationsofpracticallyallhalogenatedorganiccompoundsinindoorairhavebeenfalling.Halogenatedorganiccompoundssuchas1.1.1-trichlorethaneusedtobefoundinthingssuchas“Tipp-Ex”fluids(useprohibitedsince1991).Othersubstancesandareasofusearep-dichlorobenzenefromtoiletdeodorantblocksandmothrepel-lents,strong-smellingmono-totrichloronaphthalenesfromwood-basedmaterialstreatedwithfungicides,andchloranisolsasdecompositionprod-uctsofwoodpreservatives.Ofsignificancewithregardtohygienearethehalogen-containingorganictrihalomethanesandchloramines,whichariseinindoorswimmingpoolsasreactionproductsfrompoolwaterchlorina-tion(cf.SectionA-4).
Siloxanes
Alsofindingincreasinguseassolventsinenamelsarevolatilesiliconcom-pounds,knownassiloxanes,suchasmethylpolysiloxanes(e.g.cyclopentasi-loxane),whichareoftendetectedintheindoorair.
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Nitrogen and sulphur-containing organic compounds
Manyamines,anilinesandotherbasicorganiccompoundsareusedasproductauxiliaryagents.Theyareveryseldomdetectableinindoorairandmostlyhaveanoticeableodour.Dimethylformamidecanbegivenoffinsmallquantitiesintoindoorairfromacrylicfabric,andalsopossiblyfrommouldedlaminatedplasticparts.Sulphur-containingorganiccompoundsareusedforexampleasanodouradditive(sothatescapinggasissmelt)intownandnaturalgas.
Microbial volatile organic compounds (MVOCs)
Whenmouldgrowthoccursasaresultofdampdamageinindoorspaces(cf.SectionB-7)volatilemetabolicproductsofmicro-organisms,e.g.variousalcohol,aldehydeandketonecompoundscanenterindoorair.Someofthesemicrobiallyproducedvolatilesubstancesarelargelyspecifictomicro-organisms,whileotherscanalsoarisefromvariousothersources,suchassometerpenesoraromatichydrocarbons,liketoluene,forexample.ThesubstanceswhichshouldbeassignedmainlytomicrobialsourcesarecalledMicrobialVolatileOrganicCompounds(MVOCs).MVOCscanbemeasuredinindoorairbyspecialmethodsandusedasindicatorsforthepresenceofmicrobialdamage.IngeneralMVOCsarepresentinindoorspacesinsignificantlylowerconcentrations(lessthan1μg/m3)thanVOCs.However,owingtotheirlowodourthreshold,theycanproducenoticeableodours(seefollowingparagraph).Especiallyinthecaseofmouldgrowththatisnotimmediatelyvisibletothenakedeye,MVOCreadingscanbehelpfulinidentifyingthedamage(cf.SectionB-7).
RiskstohealthcannotbededucedfromcontaminationwithMVOCs.TheindicatoreffectofMVOCsisthesignificantpoint,andunusualreadingsshouldbeseensolelyasgroundsforacarefulsearchforhiddenmicrobialsources.
Odour active volatile organic compounds (OVOCs)
Mostvolatileorganiccompoundsdonotproducenoticeableodoursinnormallowindoorairconcentrations.Odouractivesubstances,whichexudeanoticeableodoureveninverylowconcentrationsandasaresultpossiblyalsooverafairlylongperiod,areknownasodouractivevolatileorganiccompounds(OVOCs).Theyhaveamolecularweightbelow300g/mol,arelativelylowboilingpointandeasilyenterthegasphase.Theyoftencontainpolarfunctionalgroupssuchashydroxylorcarbonylgroups,orheteroatomssuchassulphurornitrogen.Referencehasalreadybeenmadeinthepreviousparagraphstosomeexamplesofodouractivevolatile
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organiccompounds,suchasterpenes,2-ethylhexanol,aldehydes,ketones,esters,halogen,nitrogenorsulphur-containingorganiccompoundsandafewMVOCs.Acompoundofanewertypeisbutanonoxim,whichcanbegivenoffintotheindoorair,forexampleduringthehardeningofsealants.OVOCspresentamajoranalyticalchallenge,astheycanalreadyreleaseanoticeableodourinconcentrationswellbelowthenormalrequiredlimitof1μg/m3,andOVOCsareoftennotdetectedwithroutineVOCmonitoring.
BecauseofthemanydifferentVOCsitisparticularlydifficulttocarryoutacomprehensivehealthevaluationforthissubstancegroup.ManyVOCscancausenervedamageintheveryhighconcentrationsthatoccurincommer-cialworkplaces,althoughnotinschools.SomeVOCscantriggerinflam-mationoftherespiratorytract,asirritantby-productsareformedinthemetabolismofthenasalmucousmembrane.
Whetherasensitisationcanariseisamatterfordebate.SomeVOCsexhibitverylowodourthresholdsandcanthereforebesmeltintheindoorair.Insomecasestheodourthresholdsaresolowthatthesubstancescanbesmelt,andyetcannotberegisteredwithcertaintyusingtechnicalmeasur-ingmethods(seecommentsabove).
Furthermore,thetoxicpropertiesdescribedintheliteraturerelateasaruletoindividualsubstancesandtohighconcentrationsthatcouldgenerallyonlyoccuratspecificworkplaces.However,intherangeofconcentrationsthatalsoarisein“normal”indoorenvironments,non-specificcomplaintsandsymptomsareoftenassociatedwithexposuretoVOCs.Theseincludeirritationsoftheskin,eyes,mucousmembranesandrespiratorytracts,headaches,fatigue,poorconcentrationandmajorproblemswithunpleas-antodours.
TheevaluationofVOCconcentrationsinindoorairdependstoalargeextentontheaccuracyofthemeasuringcarriedoutpreviously.Beforemeasuringisundertakentheaimofthemeasurementmustbedefined.
EspeciallyafterbuildingandrenovationworkincreasedamountsofVOCsenterindoorairforashortperiod(fromdaystoseveralweeks).Raisedconcentrationscanbereducedbytheselectionofappropriatebuildingmaterialsandproducts,andthroughintensiveventilationduringandoncompletionofthework.VOCemissionscannotbeavoidedentirely.OwingtotheirdiversefieldsofuseVOCscanpracticallyalwaysbefoundinindoorair.Regularventilationistheprincipalmeansofloweringconcentrations.
How can the release of volatile organic compounds into indoor air be avoided?
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Checkingthataguidelinevalueisbeingadheredtorequiresthemeasuringtotakeplaceunderoperatingconditions.Inschoolsparticularattentionshouldbepaidtotheventilationconditions.Theresultofanindoorairmeasurementdependslargelyontheframeworkandmeasuringcondi-tions.Itisthereforeessentialtoensurethattherelevantrecommendationsareobserved(FederalEnvironmentAgencypublication.BeurteilungvonInnenraumluftkontaminationenmittelsReferenz-undRichtwerten–eineHandreichung[Assessmentofindooraircontaminationusingreferenceandguidelinevalues–sometips].Bundesgesundhbl-Gesundheitsfosch-Gesundheitsschutz50:2007,pp.990–1005;VDIGuidelinesseries4300).Onlylaboratorieswithadocumentedqualityassurancesystemwhoparticipatesuccessfullyinexternalgroupexperimentsand/orcomparativelaboratoryresearchprogrammesshouldbegiventhemeasuringcontract..
IndoorguidelinevaluesforindividualVOCsarededucedbytheadhocworkinggroup,composedofmembersoftheIndoorAirHygieneCommis-sion(IRK)andtheWorkingGroupoftheSupremeHealthAuthoritiesoftheFederalStates(IRK/AOLGadhocworkinggroup),inaccordancewithaproceduralscheme.Itisrecommendedthatthesevaluesarealsoadheredtoinsideschools(seeTable5).
Guideline value II (RW II) is a proven value relating to impacts, which is based on current toxicological and epidemiological knowledge of the impact threshold of a substance when uncertainty factors are introduced. It represents the con-centration of a substance which, when reached or exceeded, requires immediate action, since this concentration is likely to pose a health hazard, especially to sensitive individuals spending long periods in the rooms.
A reading in excess of RW II should be combined immediately with a control measurement under normal conditions of use and – as far as possible and rea-sonable – with an assessment of the internal exposure of the users of the room.
Guideline value I (RW I) is the concentration of a substance in the indoor air at which, within the context of a study of an individual substance, on the basis of current knowledge, no damage to health is to be expected, even with lifelong exposure. A value exceeding this is linked with hygienically undesirable con-tamination outside the normal range. RW I can serve as a remediation target. It should not, however, be an “end in itself”; if possible a lower value should be achieved.
AvaluehigherthanGuidelinevalueIindicatesincreasedexposureunac-ceptablefromahygieneperspective.Fromarealisticpointofviewnostruc-turalorotheralterationsrelatingtothesourceshouldbecarriedoutinthefirstinstance,butaboveallventilationand,dependingontheindividualcase,cleaningshouldbesteppedup.
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Table 5: IRK/AOLG ad hoc working group guideline values for indoor air (as at 2008): as well as VOCs this contains SVOCs (cf. Section B4) and a guideline value for mercury-containing vapours
Compound RW II (mg/m3) RW I (mg/m3) Year set
Toluene 3 0.3 1996
Dichloromethane 2(24h) 0.2 1997
Carbon monoxide 60(1/2h) 6(1/2h) 1997
15(8h) 1.5(8h)
Pentachlorophenol 1μg/m3 0.1μg/m3 1997
Nitrogen dioxide 0.35(1/2h) – 1998
0.06(1week) –
Styrol 0.3 0.03 1998
Mercury (as metallic vapour)
0.35μg/m3 0.035μg/m3 1999
Tris(2-chloroethyl) phosphate
0.05 0.005 2002
Bicyclic terpenes (lead substance α-pinen)
2 0.2 2003
Naphthalene 0.02 0.002 2004
Non-aromatic hydrocarbon mixtures (C9-C14))
2 0.2 2005
Atanytimethecurrentlistincludingfurtherinformationisdefinitive.Thisisavailableonlineat:http://www.umweltbundesamt.de/gesundheit/innenraumhygiene/irk.htm#4
TheIRK/AOLGadhocworkinggrouphasalsodrawnuprecommendationsonlimitsofindoorairconcentrationsforTotalVolatileOrganicCompounds(TVOCs).TheTVOCvalueisnottoxicologicallybased,owingtothedifferentcompositionofthemixtureofsubstancesoccurringinindoorair,butrepre-sentsatotalhygieneevaluationforVOCs.
TheTVOCevaluationisdividedinto5levels(seeTable6);therecommenda-tionsmadeatthepreviouslevelalsoapply–asfarasisreasonable–atthenextlevelup.TheprerequisiteforusingtheTVOCschemeisthattoxicologi-callybasedguidelinevaluesofindividualsubstancesarenotexceededindoingso.Aseparateassessmentisafundamentalrequirementifsubstanceswithlowodourthresholdsareinvolved,asthesecancauseproblemseveninlowconcentrationsbecauseoftheirodouractivity,orifabnormallyhighconcentrationsofindividualsubstancesoccur.
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Level 1
TVOCvaluesbelow0.3mg/m3arehygienicallyinsignificant,providedthatindividualsubstanceguidelinevaluesarenotexceeded.Theyaredesig-nated“targetvalues”(hygienicprecautionrange)andtheaimshouldbetomeetorifpossiblegobelowtheminindoorspaceswithinanadequateperiodaftercompletinganew-buildorrenovationwork.
Level 2
TVOCvaluesbetween>0.3and1mg/m3canbeclassifiedasstillhygieni-callyinsignificant,providedthatindividualsubstanceguidelinevaluesarenotexceeded.Thisconcentrationrangeindicatesforexamplethatsolventemissionsarenotyetcompletelyexpelledandpointstotheneedformoreintensiveventilation.
Level 3
TVOCvaluesbetween>1and3mg/m3shouldbeassessedasabnormalandapplyforalimitedtime(<12months)asupperlimitsforspacesintendedforlengthyoccupation.Inresidential,schoolorofficespacesinnormaluse,whererenovationorrefurnishinghasnotrecentlytakenplace,aTVOCconcentrationof1mg/m3undernormalconditionsofuseshouldnotbeexceededinthelongterm,asthiswouldbejudgedtobeanindicationofanadditionalandpossiblyharmfulVOCemission.Thehealthimplicationsofunusualinstancesofreferencevaluesbeingexceededshouldbeexam-ined.Anindividualtoxicologicalassessment,atleastofthesubstanceswiththehighestconcentrations,isrecommended.Thefollow-upmeasurementtotesttheindoorairqualityiscarriedoutundernormalconditionsofuse.
Level 4
SpaceswithTVOCvaluesbetween>3and10mg/m3areassessedashygi-enicallysignificantandshouldonlybeusedtemporarily(foramaximumof1month),ifnoalternativeisavailable,andwiththeimplementationofmoreintensiveregularventilationprocedures.Anindividualtoxicologi-calsubstanceevaluationorsubstancegroupevaluationshouldbecarriedout.Thefollow-upmeasurementtotesttheindoorairqualityiscarriedoutundernormalconditionsofuse.
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Level 5
TVOCvaluesbetween>10and25mg/m3areclassifiedashygienicallyunac-ceptable.Useoftheroomshouldasarulebeavoided;atthemostonlyshortperiodsshouldreasonablybespentthere(lessthanonehourperday),andmoreintensiveregularventilationproceduresimplemented.Atvalues>25mg/m3theroomshouldnotgenerallybeused.Thefollow-upmeasure-menttotesttheindoorairqualityiscarriedoutundernormalconditionsofuse.
AswellastheguidelinevaluesandTVOCclassificationsreferencevalues,whicharedeterminedfromthestudyofalargenumberofindoorspaces,canalsobeusedinmakingapreliminaryassessmentofVOCconcentra-tions.ThelatestreferencevaluescanbefoundinapublicationfromtheFederalEnvironmentAgency(Bundesgesundheitsbl-Gesundheitsforsch-Gesundheitsschutz50:2007,pp.990–1005).Ameasuringlaboratoryshouldspecifythesourceofthereferencevaluesusedandmustonnoaccountlinkanyhealthstatementstotheexceedingofareferencevalue(alsooftencalledanorientationvalue).
Table 6: Hygienic evaluation of TVOC values and resulting recommendations for action (Federal Environment Agency 2007)
Level / Concentration range / Questions requiring clarification / Recommendations
1
Hygienicallyinsignificant.Noproblemsasarule.
Areguidelinevaluesbeingexceeded?
Nofurthermeasures.
2
Stillhygienicallyinsignificant,providedthatnovaluesareexceededforindividualsubstancesorsubstancegroups.
Isolatedcasesofhealthproblemsorodourperceptions,e.g.afterminorrenovationworkornewfurnishingsinrecentweeks.
Areguidelinevaluesbeingexceeded?Arevaluessignificantlyabovereferencevalues?
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Aretheindoorclimateconditions(airexchange,temperature,humidity)perfect?
Adequateairing,especiallyafterrenovationwork.
IdentifyVOCsources(e.g.inspectionofthespace).
Checkuseofcleaningandpolishingproducts.
Follow-upreadingstomonitorvaluesexceedingtheguidelinevalueundernormaluse(seeChapter9).
3
Hygienicallysignificant.
Useofroomsthatareoccupiedregularlyonlyacceptableforalimitedperiod(<12months).
Within6monthsTVOCconcentrationsshouldfallsignificantlybelowtheTVOCvaluerecordedatthestart.
Incidentsofhealthproblemsorodourperceptions,e.g.aftermajorrenovationwork.
Areguidelinevaluesbeingexceeded?
Arevaluessignificantlyabovereferencevalues?
Aretheindoorclimateconditions(airexchange,temperature,humidity)perfect?
Checkvaluesexceedingtheguidelinevalueimmediatelybyfollow-upreadingsundernormaluseconditionsandbearinmindadviceinChapter4whenmakingtheevaluation.
Testvaluessignificantlyabovereferencevaluesforrelevancetohealth.
Inallcases:carryoutsearchforsourceandcheckventilationroutines:implementintensiveventilationandifnecessaryestablishconditionsforuseandventilation.
Controlreadingorfollow-upreadingrecommendedafterapprox.1month(undernormaluse).
Ifafter12months,despitetheeffortsdescribed,theTVOCconcentra-tionremainsabove1mg/m3,adequateremediationmeasuresshouldbeincorporatedinfurtherplanning.
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4
Hygienicallysignificant
Useofroomsthatareusedregularlyonlyacceptableforalimitedperiod(<1month).
TVOCconcentrationsshouldfallbelow3mg/m3within1month.
Incidentsofincreasingnumbersofhealthproblemsorodourpercep-tions,e.g.aftermajorrenovationwork.
Areguidelinevaluesbeingexceeded?
Arevaluessignificantlyabovereferencevalues?
Aretheindoorclimateconditions(airexchange,temperature,humidity)perfect?
Checkvaluesexceedingtheguidelinevalueimmediatelybyfollow-upreadingsundernormaluseconditionsandbearinmindadviceinChapter4whenmakingtheevaluation.
Testvaluessignificantlyabovereferencevaluesforrelevancetohealth.Toxicologicalevaluationofindividualsubstancesorsubstancegroupsrequired.
Inallcases:carryoutsearchforsourceandimplementintensiveven-tilation;ifnecessaryestablishconditionsforuseandventilation,andarrangeappropriateminimisationmeasures.Iftheroommustbeused,thentolerableonlywithatimelimitperdayforamaximumperiodtobestipulatedbythehealthagency(perday/numberofhours/limitedperiod).
Controlreadingorfollow-upreadingrecommendedafterapprox.1month(undernormaluse).
Ifafter1month,despitetheeffortsdescribed,theTVOCconcentrationremainsabove3mg/m3,adequateremediationmeasuresshouldbeincorporatedinfurtherplanning.
5
Hygienicallyunacceptable.
Avoidusingroomifpossible.Atmost,usepermittedforalimitednumbersofhoursoverarestrictedperiod.
Atvaluesabove25mg/m3theroomshouldnotbeused.
TVOCconcentrationsshouldfallbelow3mg/m3within3months.
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Healthproblemsandodourperceptionsusual,e.g.afterfaultyapplicationoraccidents.
Arevaluessignificantlyabovereferencevalues?
Areguidelinevaluesbeingexceeded?
Aretheindoorclimateconditions(airexchange,temperature,humidity)perfect?
Monitorvaluesexceedingtheguidelinevalueimmediatelybyfollow-upreadingsundernormaluseconditionsandbearinmindadviceinChapter4whenmakingtheevaluation.
Testvaluessignificantlyabovereferencevaluesforrelevancetohealth.Tox-icologicalevaluationofindividualsubstancesorsubstancegroupsrequired.
Inallcases:carryoutsearchforsourceandimplementintensiveventila-tion;establishconditionsforuseandventilation,andarrangeappropriateminimisationmeasures.Iftheroommustbeused,thentolerableonlywithatimelimitperdayforamaximumperiodtobestipulatedbythehealthagency(perday/numberofhours/limitedperiod).
Controlreadingorfollow-upreadingwithin1month(undernormaluse).
Ifbyimplementingminimisationmeasuresavaluebelow10mg/m3isachievedwithinthetimeframeunderconsideration,butaconcentrationof3mg/m3stillexceeded,therecommendationsinLevel4apply.Ifafter1month,despitetheeffortsdescribed,theTVOCconcentrationremainsabove10mg/m3,theroommustnotbeusedandadequateremediationmeasuresshouldbearranged.
B-3 Formaldehyde
Formaldehyde(chemicalname:methanal–CH2O)isoneofthebestknown
andbestresearchedairpollutantsinindoorspaces.Asaresultofitsdiverseindustrialusesinthemanufactureofsheetandinsulationmaterials,paints,cleaningagentsandcosmeticsthesubstancecanusuallybedetectedinin-doorair.Wood-basedmaterials(particleboard,coatedparticleboard,woodcoreplywood,veneers,fibreboard)andarticlesproducedfromwood-basedmaterialssuchasfurniture,doorsandpanellingarestillthemostimportantsourcesofformaldehydeinindoorareas.
Formaldehydeisanimportantconstituentofadhesivesinthesheetmate-rialindustry.Amongstthoseusedareureaformaldehydeadhesiveresins(UFglues),phenol-formaldehydeadhesiveresins(PFglues),melaminefor-
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maldehydeadhesiveresins(MFglues)andmelamine-urea-formaldehydead-hesiveresins(MUFglues).Aftercompositewoodmaterialsmanufacturedinthiswaywereusedforlargesurfacesandinstallationstherewereincreasedemissionsofformaldehydeintheindoorairinschoolbuildingsinthepast,andeventodaytherestillarestilloccasionalinstances.
Sincethebeginningofthe1980sformaldehydeemissionsfromwood-basedmaterialshavebeenregulatedinGermany.TheChemicalsProhibitionOrdi-nance(Chemikalien-Verbotsverordnung)stipulatesthatonlythosecompositewoodmaterialswhichareprovennottoexceedanaverageconcentrationof0.1ppmunderdefinedtestconditions(“emissionclassE1”)maybeputonthemarket.Exceptionstothisarewood-basedmaterialstobelaminated,forinstanceformakingfurniture,whichisstillpermittedtoemitsignificantlymoreformaldehydenowadays.Asanexample,E1wood-basedmaterialsforuseasflooringarenowstandard.Sheetmaterialproductsthatareparticular-lylowinformaldehyde(averageconcentrationinatestchamber<0.05ppmunderdefinedconditions)canbeidentifiedbytheBlueAngel.Theamountofformaldehydegivenofffromcompositewoodmaterialsisalsoinfluencedbytheclimaticconditionsintheroom.Thushigherindoorairtemperaturesandhigherrelativehumidityleadtoanincreaseinemissionsrates.
Somemanufacturershavestoppedaddingformaldehydetotheirwood-basedmaterialsandinsteadusepolyurethanegluesforadhesion.Althoughthediisocyanatesinthesearelikewisenottoxicologicallyinsignificantduringthemanufacturingprocess,theydohoweverremainboundupinthewood-basedmaterialsafterwardsandthereforedonotentertheindoorair.
Intermsofhealthimpactsthroughexposuretoformaldehydeinindoorenvi-ronmentsirritationofthemucousmembranesisthemostsignificant.Withlong-lastinghighformaldehydepollution,whichoccurredatsomeworkplac-esinpreviousdecades,theirritationcanleadtochronicinflammationofthenasalmucousmembrane,fromwhichcancercandevelop.In2004formalde-hydewasclassifiedas“carcinogenictohumans”bytheInternationalAgencyforResearchonCancer(IARC).
Formaldehydehasapungentodour.TheWHOestimatesthatsomepeopleperceivetheodourofformaldehydeevenat0.03mg/m3.Aslongagoas1977theGermanFederalMinistryofHealth(BGA)recommendedaguidelinevalueof0.1ppm(=0.12mg/m3)offormaldehydeinindoorair,regardlessoftheactualindoorairtemperaturesandhumidity.Inviewofthere-evalu-ationofthecarcinogeniceffectofformaldehydethisvaluewasre-examinedandconfirmedbytheFederalInstituteforRiskAssessment(BfR)in2006.TheIndoorAirHygieneCommission’sadhocworkinggroupendorsedthisproposal.Intheviewofthesecommitteestheriskofcancerbelow0.1ppmofformaldehydeisnegligible.
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B-4 Semi-volatile organic compounds (SVOCs)
Thegroupofsemi-volatileorganiccompounds(SVOCs)includessubstancesandsubstancegroupswhoseboilingrangeliesabovethatofVOCs(seedefinitioninSectionB-2).FormostSVOCsingestionfromfoodsofanimaloriginrepresentsthemainexposurepath.However,SVOCscanalsobeabsorbedviaindoorair.IntheindoorenvironmentthevastmajorityofSVOCspresentareboundtosuspendeddustparticlesortosurfacesintheroom.AmongthemostfamiliarSVOCspresentinsignificantquantitiesarethefireretardantsandsoftenersusedinplasticproducts.Theseandothercompounds,whoseappearanceinrecentdecadeshasbeenthesubjectofparticularlyintensivediscussions,includinginschools,namelypolychlorin-atedbiphenyls(PCBs),agentsinwoodpreservativesandpolycyclicaromatichydrocarbons(PAHs)willbedealtwithinmoredetailbelow.
Fire retardants
Fireretardantsaredesignedtomakeplastics,woodandcompositewoodmaterials,insulatingmaterialsandtextilesnon-flammable.Thefireretard-antsareintheformofanadditivemixedintotheproducttobeprotectedorareboundupreactivelyinthematerial.Thesubstancesappliedasadditivesinparticularcanbereleasedintotheenvironmentagainlater.Variousinorganicand/ororganicsubstancegroupsareusedasfireretard-ants,inEuropebeingmainlyaluminiumoxides,boronoxides,magnesiumoxidesandantimonyoxides,chlorinatedparaffins,variousbrominatedcompoundssuchaspolybrominateddiphenylethers,andhalogenatedandnon-halogenatedorganophosphateesters(OPEs).Fire-retardantagentsinplasticsoftenalsoperformthefunctionofasofteneratthesametime(e.g.polybrominateddiphenylethers).
Todatethereleaseoffireretardantsintotheindoorenvironmentundernormallivingconditionsorduringnormalusehasbeenpoorlyunderstood.Researchintotheoccurrenceofphosphoricacidestersinindoorairwasonlycarriedoutinthe1990s.Phosphoricacidestersweredetectedeveninreadingsfromhousedust.
Aswellastheirtoxicpropertiesthedurability(persistence)andabilitytoincreaseinthebody(bioaccumulation)offireretardantsalsoplayapart.Aparticularlynegativeexampleofthisisthepolychlorinatedbiphenyls,whichhoweverhavenotbeenusedasfire-retardantagentsforsometime(seefollowingsectiononPCBs).TheorganobrominatedcompoundsandOPEsarealsocriticalinthisrespect.TheIRK/AOLGadhocworkinggrouphasproposedasumguidelinevalueforindoorair(RWI)of0.005mg/m3
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fortris(2-chloroethyl)phosphate(TCEP),tris(2-chloroisopropyl)phosphate(TCPP),tri-n-butylphosphate(TBP),tris(2-butoxyethyl)phosphate(TBEP),tris(2-ethylhexyl)phosphate(TEHP)andtriphenylphosphate(TPP)(cf.guide-linevaluesinSectionB-2).
Softeners, phthalic acid esters
Phthalicacidesters(phthalates)areaddedtoplasticsassoftenersinlargequantities(mostlymorethan10%).Forthisreasontheyaresomeofthesubstanceswhicharefoundinrelativelyhighconcentrationsinmostenvi-ronmentalmediaandespeciallyinfoodaswell.Owingtotheirlowvolatil-itysoftenersarefoundinindoorenvironmentslessintheairthanindustdepositsandonsurfaces.Potentialemissionsourcesofphthalicacidestersinindoorareasarewallcoverings,wallpaints,floorcoveringsandelec-tronicequipment.Buildingmaterialsforwallsandfloorscanbearelevantsourceofphthalicacidestersbecauseoftheconsiderableproportionofsurfaceareainaroom.ThePVCusedbypreferenceinwallandfloorcover-ingscanforexamplehaveaphthalicacidestercontentofmorethan30%.Untiltheendofthe1990sthismainlyinvolveddi-n-butyl-phthalate(DBP),diisobutylphthalate(DiBP)anddi(2-ethylhexyl)phthalate(DEHP).Nowadaystheuseofdi-iso-nonylphthalate(DINP)ispreferred.Thediacidesterssuchasadipateswhicharealsousedassoftenershaveasyetseldombeendetectedinindoorenvironments.Phthalicacidestersaresuspectedofencouragingthephenomenonof“blackhomes”(thefoggingphenomenon).
Polychlorinated biphenyls
Polychlorinatedbiphenyls(PCBs)wereproducedindustriallyfrom1929tothebeginningofthe1980s.Theyareamixtureofvariouschlorinatedsinglecompounds(amaximumof209differentcompoundtypes[conge-ners]).Inthepasttheywerewidelyusedasinsulators,fireretardantsandsofteners.TheirsaleandusehasbeenprohibitedinGermanysince1989onaccountoftheirpersistence,theaccumulationintheenvironmentandespeciallyinthefoodchain,andtheirtoxicity.Sincethenconcentrationsintheenvironmentandalsointhefattytissueofthehumanbodyhavebeenfallingslowly.
AttentionwasfirstdrawntotheoccurrenceofPCBsinindoorenvironmentsinthemid-1980sbyPCBsleakingfromcondensersforfluorescenttubes.Inthemeantimethesehavebeenreplacedanddisposedof,assince1.1.2000condenserswithaPCBcontentofover50mg/kgmaynolongerbeused.PCBswerealsousedonalargescaleassoftenersinjointingcompounds(onapolysulphiderubberbase)andinflame-retardantorsound-absorbingcoatingsforacousticceilings(seesectiononfire-retardants).Withthese
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“open”applicationsPCBcouldenterthesurroundingairdirectly.InthecourseoftimeevenstructuralcomponentsanditemsoffurnitureintheseroomsthatwerefreeofPCBscouldbecontaminatedbythem,andtheninturncontributetoindoorairpollution(so-calledsecondarysources,e.g.floorandwallcoverings).Inthemainthisaffectedschoolbuildingserectedinthe1960sand1970s.
Owingtothehighcostoftakingreadings,notallpossiblePCBcongenersinindoorairaremeasured.Insteadmeasurementsarerestrictedtothe“in-dicatorPCBs”.TheseincludePCBs28,52,101,138,153and180.AssomePCBcongenersalsoexhibitadioxin-likeeffect,theFederalEnvironmentAgency’sadhocguidelinesworkinggrouphasrecommendedincludingPCB118,astheleadsubstanceinthissubstancegroup,since2007(Bund-esgesundheitsbl-Gesundheitsforsch-Gesundheitsschutz50:2007,pp.1455-1465),especiallywhenitisascertainedbyinvestigationsormeasurementsthatmainlyhighlychlorinatedclophenshavebeenused(perhapsinceilingboardsorcoatings).
Twocasesshouldthereforebedistinguished:
a)IfjointsealantscontainingPCBswithachlorinationgradelowerthanClophenA60aredefinitelypresent,thetotalPCBs,basedon6in-dicatorPCBs(excludingPCB118),serveasanassessmentcriterion.Measurestoreduceexposureshouldbeexaminedforindoorairconcentrationsabove3μgpercubicmetrefortotalPCBs.Atlowercon-centrationsventilationroutinesshouldbeinvestigatedandimprovedifnecessary.
b)ForceilingboardsandcoatingscontainingClophenA50orClophenA60andPCBsourcesthatcannotbeidentifiedwithcertaintythetotalPCBcontentcanlikewisebeusedtomakeanevaluation.Uptoaconcentrationof1μgtotalPCBs/m3willcertainlybebelowaTEQ(toxicequivalentquantity)valueof5pg/m3.AthighertotalPCBcontents(>1μg/m3)theconcentrationofPCB118shouldbeusedforassessment.Forindoorairconcentrationsabove0.01μgPCB118/m3measurestoreduceexposureshouldbeinvestigated.Atconcentrationsbelowthisventilationroutinesshouldbeinvestigatedandimprovedifnecessary.
AtpresentthereareconsiderabledifferencesbetweentheLänderwithregardtothehealthevaluationofPCBsinindoorairandtotheextentofnecessaryremediationmeasures.InmanyoftheLändersubstantialpartsoftheGermanInstituteforConstructionEngineering’s“GuidelinesfortheassessmentandremediationofPCB-contaminatedbuildingmaterialsandcomponents(PCBGuidelines)”havebeenintroducedastheacknowl-
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edgedtechnicalrulesforworks,whileinotherLändertheyonlyapplywithsubstantialamendments.InordertofacilitateaprocedureforthewholeofGermany,theadhocworkinggrouprecommendsinits2007statementthatthehealthevaluationofPCBsiscarriedoutdependentonthetypeofPCBsource(sealants,ceilingboards,etc.).
TherearealsodifferentregulationsintheLänderwithregardtohealthandsafety.Thehealthandsafetyrecommendationsapplicableineachcaseshouldbeobserved.
Asabasisfororderingfurtheractiontobetakenacontrolmeasurementunderdefinedventilationconditionsshouldbeundertaken:inindoorspac-eswithventilationregulationssuchasschoolsnormallong-termmeasuringforPCBsshouldbecarriedoutduringseveralcyclesofuse,whileadheringtotheprescribedventilationwiththeroomsinnormaluse,withventila-tionduringbreaktimestakingplaceasprescribed.Themeasuringbeginsafterthefirsttimethewindowsareclosedandendsbeforethelasttimethewindowsareopened(includingseveralcyclesofuse).Themeasure-mentsshouldpreferablybecarriedoutwhiletheroomisinuse.Ifpossible,measuringshouldtakeplacethroughoutatleastonecompleteschoolday,inordertoregistertheinfluenceoftemperatureinthecourseoftheday.
ThefundamentalaimofPCBremediationshouldbetoremovetheprimarysourcesandminimisethesecondarysourcesasfaraspossible.Duringreme-diationworktheARGEBAU(ConferenceoftheLänderMinistersandSena-torsresponsibleforurbandevelopment,constructionandhousing)guide-linesfortheevaluationandremediationofPCB-contaminatedconstructionmaterialsandcomponentsinbuildingsshouldalwaysbeobservedintheversionapplicabletotheappropriateLand(cf.PartE).
Pentachlorophenol
Untilwellintothe1970stimberandtimbercladdinginindoorenviron-mentswasoftentreatedwithwoodpreservativescontainingpentachlo-rphenol(PCP),withpolychlorinateddibenzodioxinsanddibenzofuransascontaminants.Becauseoftheirlonghalf-lifeintreatedwoodPCP,dioxinsandfuranscanstillbedetectedintheseindoorareastoday,althoughtheuseofPCPhasbeenprohibitedinGermanysince1989.SomeofthePCPreleasedfromthewoodistakenupbythedustintheroomandbyfurni-ture,curtainsorcarpets.PCPuseshouldalwaysbeassumedifvaluesabove0.1μg/m3ofindoorair,morethan5μgPCP/ginaccumulateddust(olddust)andmorethan1μg/gin“freshdust”(dustthathasnotlainforlongerthanoneweekbeforethesampleistaken)aredetected.
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Iftheindoorairconcentrationtobeexpectedinthemiddleoftheyearisabove1μg/m3,remediationisrequired.Afterremediationtheaimshouldbetoachievelong-termindoorairvaluesbelow0.1μgPCP/m3ofair.RegulationsondeterminingtheneedforremediationinPCP-contaminatedspacesandsuggestionsforsuitableremediationaresetoutintheARGEBAUguidelinesontheevaluationandremediationofconstructionmaterialsandcomponentsinbuildingscontaminatedwithpentachlorophenol(PCP)(“PCPguidelines”)–seePartE.
Ifchemicaltreatmentagainstinsectswasneededatallforwood,dichloflua-nidwasthefirstsubstituteforPCPavailable,followedbytebuconazole,propiconazoleandotheragents.
Lindane
Lindane(gamma-hexachlorocyclohexane;γ-HCH)wasusedasaninsecticideinagricultureandforestry,woodpreservationandveterinaryandhumanmedicinefromaround1945.Foralongwhilelindanewasparticularlyim-portantincontrollingwood-destroyinginsectsandinpestcontrolmeasuresaspartoftheGermanFederalCommunicableDiseasesControlAct(Bundes-seuchengesetz).
Atthattimelindanewasusuallypresentin“WestGerman”woodpreserva-tivesincombinationwithpentachlorophenolinaratioofaround1partlindaneto10partsPCP.InEastGermanyacombinationoftheagentsDDTandlindanewaspreferred.Sincelindanewasgenerallyusedasanagentinwoodpreservativestogetherwithpentachlorophenol,itisprimarilythePCPcontaminationthatisinevidenceinaffectedschoolrooms.Therefore,bycarryingoutPCPremediationinaccordancewiththePCPguidelines,lindanecontaminationwillgenerallybereducedatthesametime.
It isnotnecessary tousechemicalwoodpreservativeswithbiocidalagents inindoorenvironments.Inthecaseofpestinfestationalternativewoodtreatments(e.g.thermalconditioning)canbeusedifneeded.
Chemicalwoodpreservativesshouldnotbeusedinconstructioncomponentsandfittingsthatarevisibleandaccessibletotheroom.
Is the use of chemical wood preservatives still permitted nowadays?
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Chloronaphthalenes
Untilwellintothe1970schloronaphthaleneswereusedaswoodpreserva-tivesinthemanufactureofbondedwood-basedmaterials,especiallyparticleboards.Thesewereusedasflooringsheetsandtoasmallextentaswallandceilingliningsaswellasindemountablebuildingswherechildren’sdaynurseriesandpre-schoolplaygroupswerehoused.Themixturesconsistedpredominantlyofmono-anddichloronaphthalenes.Chloronaphthalenescouldberecognisedbytheirtypicalmustysmell(cf.SectionD-2.2).
AguidelinevalueI(RWI)of20μg/m3andaguidancevaIueIIof200μg/m3fortheevaluationofchloronaphthaleneswereproposedbytheFederalMin-istryofHealthofthetime.Whenmakingahygieneevaluationofindoorenvironmentscontaminatedwithchloronaphthalenestheunpleasantodouremittedbythesubstancemustalsobeconsidered.Odourthresholdvaluesintherange4–10μg/m3arespecifiedforthemonochloronaphthalenes.
Polycyclic aromatic hydrocarbons
Polycyclicaromatichydrocarbons(PAHs)arisefromtheincompletecombus-tionoffossilfuelsorotherorganicmaterials.Morethan200ofthesecom-poundsexhibitingthreeormorebenzeneringsaretobefoundinoutsideair,especiallyinconurbations.InindoorenvironmentsPAHscanentertheairfrom,forexample,tobaccosmoke,leakingfluesfromcoalstovesandfromusingpoorlyfunctioningfireplaces.
TarandtarproductsalsocontainPAHs.Untilthe1950sand1960star-basedadhesives(ormixturesoftarandbitumen)weresometimesusedinlayingwoodfloorsandoccasionallyalsoinlayinglinoleumfloorcoverings,mainlyinhousesandflats.However,onlyafewcaseswhereadhesivesofthiskindwereusedinschoolshavesofarcometolight.Inindoorenvironmentswheretar-basedadhesivematerialshavebeenused,anincreasedPAHcon-tentinthegluecanalsocausehousedusttobecontaminatedbyPAHs.
ManyPAHsareclassifiedascarcinogenic,includingbenzo(a)pyrene(BaP),theleadsubstanceinthePAHs.In1998acommissionofexpertsattheFed-eralEnvironmentAgencyissuedrecommendedvaluesforbenzo(a)pyrene(BaP)asthePAHleadsubstanceforadhesivesandhousedustcontent.Thesewerealsoadoptedbytheconstructionauthority(ARGEBAU).Inaccordancewiththese,measurementsofhousedustconcentrationsaretobecarriedoutwhenconcentrationsinadhesivesexceed10mg/kgBaP,takingintoconsid-erationtheconditionoftheparquet.IftheBaPcontentexceeds100mg/kgofdust(dustdepositsnomorethanaweekoldatthetimeofsampling)measurestoreduceexposureshouldbeundertakeninschools(GermanInstituteforConstructionEngineering,“AdviceonPAHs”,June2000).
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B-5 Dust
Dustisthecollectivetermforsolidparticlesthatremaindistributedthroughtheairoverafairlylongperiod(suspended)orsettleonthefloorandonsurfaceswithinashorttime(sedimentary).Dustparticlescanvaryconsiderablyinsize.Particlessmallerthan100nmaretermedultra-fineparticulatematter,particlesupto2.5μmparticulatematterandparticleslargerthan2.5μmascoarserparticulatematter.Allparticlesuptoadiam-eterofaround30μmaresuspendeddust(TSPs–TotalSuspendedParticu-lates).Dependingonthesizeanddensityofthedustparticlestheseremainsuspendedforacertaintime.Particlesof10μmandmoreareoftendepos-itedwithinafewminutes.Finerparticlesof,forexample,1μm,canremainsuspendedforseveraldays.Veryfineparticlesof,forexample,10nm,reactwitheachotherintheairandformlargerparticles,oraretakenupbylargerparticles.
Thesmallerparticlesare,thefurthertheycanpenetrateintotherespiratorytracts.Particlesmorethan10μminsizewillbarelygetbeyondthelarynx,andonlyasmallminorityofthemcanreachthebronchialtubesandthepulmonaryalveoli.Ultra-fineparticlescanenterthebloodstreamviathepulmonaryalveoliandspreadthroughthebodyviatheblood.
Itisnotonlythesizeoftheparticleswhichiscrucialforthehealthim-pactofdusts,butalsotheirchemicalandbiologicalcompositionandtheirmorphologicalstructureandform.Aswithparticlesize,thecomposition,structureandformarecharacterisedbythetypeofsourcefromwhichtheyemanate.
Withregardtotheclassificationofdustsadistinctionshouldbemadebe-tweenparticulatesinoutsideandindoorair.Itcanbeassumedthatoutsidetheconcentrationofparticlesintheairisveryquicklydiluted.Theparticleconcentrationsandcompositionsareoftensimilar,exceptduringspecialweathersituationsandinspeciallocalconditions.
Thesituationinindoorenvironmentsisquitedifferent;herethedistribu-tionareasareconsiderablysmaller.Dilutioneffectsarenotasusefulasintheairoutsideandinthiscaseareparticularlydependentonventilationmethodsandaircirculationinthebuilding.Furthermore,inindoorareasitmustbetakenintoaccountthatparticleswillreactmorevigorouslywitheachotherorwillbegivenoffbywallsurfaces.Electrostaticprocessesintheairalsoinfluencethedistributionandemissionofparticles.Thesourcesintheindoorenvironmentvaryandaredependentonindividualuse.Sedimentaryparticlescanbereturnedtemporarilytothesuspendedstatethroughmechanicaldisturbance.Asthishappensthestructureandproper-
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tiesoftheparticlescanalter.Theprocessesmentionedarelargelydepend-entontheexistingstructuralconditionsatthesite.Thisallleadstoawidevariationinthelevelofpollutionanditscompositionintheindoorenvi-ronment,andtoitbeingheavilycharacterisedbytheprevailingindividualcircumstances.
Avarietyofsourcesofparticulatematteroccurinsideschools.Herewearemainlyconcernedwithcoarserparticulatematter.Sourcesofthisare:
Outsideair
Dustbroughtinonshoesandclothes
Particlesreleasedfromskinandhair
Particlesreleasedduringcookingandbakinginhomeeconomicspracticalareas(somecoarserparticles)
Workintechnologylessons,especiallysandingandsawing.
Inadditionsmallerparticlesalsooccur.Sourcesoftheseare:
Outsideair
UseofBunsenburners,andburningcandles
Smokeproductionfromchemistryandphysicsexperiments
Particlesreleasedduringcookingandbakinginhomeeconomicspracticalareas(somesmallerparticles)
Copiersandlaserprinters.Inthiscaseultra-fineparticlesplayapar-ticularlyimportantpart,asthemostrecentresearch,includingattheFederalEnvironmentAgency,shows.(Theresultsofthestudyareavail-ableat:http://www.umweltdaten.de/publikationen/fpdf-l/3016.pdf)
Outsideairconcentrationsofsuspendedparticulatematteralsohaveaconsiderableinfluenceontheconcentrationsoffinerparticlesinschools,whilethecoarserparticulatematterelementmostlycomesfromindoorsources(seeabove).Inareasoftheschoolusedregularlytheparticulatematterconcentrationinsidecanbemarkedlyhigherthanintheoutsideair.Thisappliesespeciallytothecoarserelementoftheparticulatematter.Thedustconcentrationinsideschoolsdependsamongstotherthingsonthefrequencyofuse(numberofpupils,howoftentheroomisused),thesizeoftheroomandthetypeofuse(classroomsfortheoreticalsubjects,laborato-riesforphysics,biologyandchemistryexperiments,craftrooms,etc.).
Intechnologylessonsdustiscreatedbysandingandsawing.InchemistryandphysicslaboratoriesdustiscreatedbyexperimentsproducingsmokeandbyusingBunsenburners(cf.SectionA6).Incidentsofdustpollution
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duringscienceexperimentsandcraftworkcanbeminimisedbyintensiveventilation,usingextractorsduringparticularsandingproceduresand–ifnecessary–wearingasimpleprotectivefacemask(e.g.fromtheDIYstore).
Besideschemicalsubstances,biologicalsubstances,suchasmicro-organ-isms,bacteriaandtheirmetabolicproductsandcellcomponents,pollenanditscomponents,aswellasallergensgivenoffbyanimals,arealsoboundtodustinschools.
Inthecaseofbiologicaldusts(cf.SectionB-7),weareconcernedpredomi-nantlywithcoarserdusts,whichcanproducesomeveryspecificimpacts,especiallyinpeoplewithcorrespondingpredispositions(e.g.thosewithallergies).Cellcomponentswhichcantriggerallergenicortoxiceffectscanalsomakeupanelementoffineorultra-fineparticulatematter.
Duringcombustionprocessesmainlyfineparticulatematterandalsosomeultra-fineparticulatematteraregivenoffintotheindoorair.Toasmallextentfineandultra-fineparticlesarealsoreleasedwhilelaserprintersandcopiersareinuse(cf.SectionA-7).However,thesedimentaryparticlesstirredupagainbymechanicalactivities,e.g.duringlessonsintheclass-room,arepredominantlycoarserparticles,whennotonlydustlyingonthefloororthedesksisraisedagain,butalsothatwhichisfoundontheskin,hair,clothes,etc.Itshouldalsoberememberedthatsomeofthisdustisbroughtinfromoutside,onshoes,forexample.
Ahealthevaluationofsuspendedparticulatematterinindoorenviron-mentsisdifficult,aspopulation-relatedstudiesoftheimpactofparticulatematterrelytoalargeextentondataonparticulatematterpollutionoftheoutsideair.Convincinglinkswerefoundbetweenthesuspendedparticulatematterconcentrationintheoutsideairandeffectsonhealth–eventhoughthepeoplewherethestudieswerecarriedoutspentthebulkoftheirtimeindoors.Fromthatcanbeconcludedthatevenindoorstheparticulatematterfromtheoutsideairmakesasignificantcontributiontotheeffectsobserved.Itisnotyetclearwhatfurthercontributionismadebyindoorsources.
IntheirlateststatementtheIRK/AOLGadhocworkinggroupalsocomestotheconclusionthatthehealthimplicationsofdustsinindoorenvironmentsaredifficulttoevaluateatpresent(IRK/AOLGadhocworkinggroup,2008:GesundheitlicheBedeutungvonFeinstaubinderInnenraumluft[Signifi-cancetohealthofsuspendedparticulatematterinindoorair],Bundesge-sundhbl-Gesundheitsforsch-Gesundheitsschutz,inpress).Theassessmentcriteria(limitvalues)usedtoassessparticlesinoutsideairarenotapplica-bletoschools,onaccountofthedifferentsourcesituationandcompositionofparticulatematter.
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Lateststudieshavethereforedetectedmainlycoarserparticulatematterparticlesinclassrooms.However,accordingtocurrentknowledgeitisinfactthesmallerparticles(especiallyPM2.5andevensmallerparticles)thatareparticularlyimportantfromahealthperspective.Biologicalparticlesrepresentonepossibleexceptiontothis.
Despitetheuncertaintiessurroundingthehealthevaluationofparticulatematterintheindoorenvironmentitseemsadvisable,bearinginmindthepossiblerelationship,tominimisethedustconcentrationinthesespaces.VariousstudiesinGermanyhaveshownthatareductionindustpollutioninschoolscanonlybeexpectedwithregularintensiveventilationandstrictadherencetocleaningrecommendations(cf.Appendix1).
B-6 Fibre dusts
Thetermfibredustsdenotesparticleswithafibrousorneedle-likestructure.Importantfromahygieneperspectivearefibreslongerthan5μm,withadi-ameterlessthan3μm,whichexceedalengthtodiameterratioof3:1.Thesefibresareknownascriticalfibres.Theycanpenetratethelungtissueduringinhalation.
Therearenaturalfibresandsyntheticallyproducedfibres.Thesetwocatego-riescanbefurthersubdividedintoinorganicandorganicfibres.
Amongthenaturalinorganicfibresareasbestos,talcumandgypsum,whilethenaturalorganicfibresincludesheep’swool,animalhairandcellulosefi-bres.Importantsyntheticallyproducedinorganicfibres–alsocalledsynthet-icmineralfibres(SMFs)–areglass(amorphous)fibressuchasmineralwool(glasswool,rockwool,slagwool),ceramicfibres,continuousglassfilamentsandcrystallinefibres/single-crystalfibres.Inadditiontherearesyntheticorganicfibres(fibresproducedfromnaturalorsyntheticpolymers).
Effectiveventilationiskeytoreducingconcentrationsofparticulatematter,espe-ciallycoarserparticulatematter,inindoorairinschools.Aslongasthereisnosmoking,theparticulatematterconcentrationinindoorspacesdependsmainlyonthequalityoftheairoutside.
Measures to reduce the entry of particulate matter from the outside air, suchasinstallingmechanicalventilationsystemswithfiltersforincomingair,shouldonlybeconsideredinsituationswithextremelypollutedoutsideair.Thesesystemsshouldbeservicedregularly(changingfilters,checkingthatventilationshaftsarecleananddonotleak).
How can particulate matter pollution in schools be reduced as quickly as possible?
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Asbestos
Buildingproductscontainingasbestoswerestillusedinschoolbuildingsintothe1980s,andadistinctionismadebetweenmaterialsmadeofasbes-toscement(withanasbestoscontentofapprox.15%byweight)andlooselyboundasbestosproducts(e.g.asbestosspray,withanasbestoscontentofmorethan60%byweight).Asbestoscementproductswereusedasroofandfaçadepanels,windowsillsorwindowboxes,drainpipesandforparti-tionwalls(lightweightwalls).Asbestosspraywaspreferredinair-condition-ingandshaftsystemsforfiresafetyreasons.
Asaresultofageingprocessesandyearsofusethesebuildingshavegradu-allybeguntoreleasefibres.Especiallywhereventilationshaftsystemshadbeenspray-coatedwithasbestos,fibresreleasedbythiscouldenteradjoin-ingroomsdirectlywiththeairflow.
Do asbestos and SMF fibres have the same importance for health?
Thestructureis importantforthereleaseoffibresofthecriticalsize.Asbestosfibresarecrystalline fibres,whereasSMFsaregenerallyamorphous.The latterexhibitasignificantly lowertendencyto formdust.Unlikeasbestos theybreakacross thegrainandhavea lowerbiopersistence.Theyarealsoboundbysyn-theticresinandotheradditives.Thesefactorsrestrictthereleaseoffibredust.
Is asbestos still a problem in schools today?
Buildingmaterialscontainingasbestosarenolongerusedinschools.Ingeneraltheasbestosfibresintheasbestoscementproductsinstalledinthepastarefirmlyboundinthebuildingproduct.However,ifanyworkisdoneontheseproducts(e.g. drilling, sanding or cutting), large numbers of asbestos fibres can be re-leased.Forthisreasonworkofthiskindisnotpermitted.Inthecaseofasbestosspray,whichwasfrequentlyusedinair-conditioningshafts,forsealingcavities,etc.,thefibresarelessfirmlyboundthaninasbestoscementproducts,sothatthereleaseoffibresasaresultofageingistobeexpected.
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Asbestosisclassedasaknowncarcinogenicforhumans.Theinhalationofasbestosparticulatemattercancausethreemaindiseases:
1. Asbestosis:hardeningofpartsofthelungtissue.
2. Lungcancer,oftenincombinationwithasbestosis,latencyperiod(timeuntilthediseaseemerges)20–30years.Smokersareespeciallyaffected.
3. Pleural/peritonealcancer(mesothelioma),latencyperiod30–40years.
Theseasbestos-relateddiseasesoccurredespeciallyamongemployeesintheasbestosindustry,inwhoseworkplacesupto100millionasbestosfibresm3ofairweremeasured.
Theevaluationofanddecisiononremediationforlooselyboundasbestosproductsinbuildingsmustnotbemadeonthebasisofairmeasurements,butusingtheasbestosguidelinesintroducedintobuildingregulationsin1996,inwhichtheneedforremediationandtheurgencyforitareestab-lishedaccordingtoapointssystem.Fibremeasurementsfromtheairareonlyrequiredtocheckthesuccessofthemeasurestaken.
Synthetic mineral fibres (SMFs)
Syntheticmineralfibresarefrequentlyfoundinschools.Incontrasttoasbes-tosfibresthesedonotoccurnaturally,butareproducedindustriallyfromvariousinorganicsourcematerials(glass,rockssuchasbasalt,oxideceram-ics).Theyareusedmainlyforthermalandsoundinsulation.ThusSMFshaveacompletelydifferentrangeofusesfrompreviousasbestosproducts.
SMFsareusedtomakemineralwool(e.g.glasswool,rockwool)forfelts,matsorboardsaswellasforloosewool.Syntheticmineralfibreproductsdisplayexcellentheatresistanceandgoodinsulatingproperties,andarerelativelyeasytoworkwith.Aswithallmineralfibreproducts,thosemadeofmineralwoolgiveofffibredusts,onaccountoftheparticularpropertiesofthemate-rial(seenotesinbox),althoughfarlessthanasbestosproducts,forexample,whichinanycasewereemployedinareasotherthanheatinsulation,asdescribedabove.
Sincethe1980s,andstillmoresincethe1995ThermalInsulationOrdinance[Wärmeschutzverordnung]andtheBuildingEnergyConservationOrdinanceof2002,severalmillioncubicmetresofmineralwoolproductshavebeenusedinbuildings.
MineralfibresbuiltintosuspendedceilingconstructionsforsoundinsulationpurposesorintheformofacousticceilingboardshaveprovokeddiscussionaboutthepossiblereleaseoffibresfromSMFproductsintoindoorair,since,toprovideeffectivenoisecontrol,theceilingconstructionsmustbeperfo-ratedontheroomside,withthemineralwooljustlyinglooselyontop.
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Extensivemeasurementscarriedoutinavarietyofbuildingsatthebegin-ningofthe1990sshowedthatingeneral,wheremineralfibreinsulationhadbeenusedasdirected,noconcentrationsofSMFsexceedingthenormalbackgroundconcentrationsintheairoutsidewererecorded.
Inthenormalusephaseofbuildings,theconcentrationsthereinofSMFfibresofcriticalsize,whichcanbeclearlyassociatedwiththeproductused,are:
usuallynot raisedbyfibreemissions,ifheatinsulationhasbeencarriedoutproperly(insulationontheoutsidewall;double-skinwallwithinsu-latinglayerbetween;installationinsidetheroomorintheroofspacebehinddensepanelling,e.g.plasterboard,woodpanelswithvapourbarrierbehind(polyethylenefilm)and/orcomparableconstructions);
usually moderately raisedbyfibreemissions,ifthemineralwoolproductsareinstalledinsuchawaythatairisexchangedbetweenthemandtheindoorenvironment.Thisismainlythecasewithsuspendedceil-ingswithoutaproperlyfunctioningfilterlayer;
inisolatedcasessignificantly raisedbyfibreemissions(uptoseveralthousandfibresperm3ofair).Thisisconstantwheretherearecon-structionalfailingsorstructures,whichdonotconformtothelatesttechnicalstandards,ortemporaryifstructuralworkisbeingcarriedoutonbuildingcomponentscontainingmineralwool.
Since1998,inaccordancewiththeHazardousSubstancesOrdinance,syn-theticmineralfibreshavebeenclassifiedbytheirsubstancecompositionusingtheKI-Index(carcinogenicityindex)1:
KIvalue<30:K2–substancesthatshouldberegardedascarcinogenicinhumans.
KIvalue>30to<40:K3–substancesgivingcauseforconcernbecauseofpossiblecarcinogeniceffect.
KIvalue>40:nocarcinogenicityclassification.
FibreswithaKI>40areconsideredfreeofsuspicionofcausingcanceronthebasisofcurrentknowledge,astheyhaveabiopersistenceofonlyapprox.30–40days.AccordingtotheChemicalsProhibitionOrdinancethebiosolubilitycanalternativelybeestablishedthroughothermethodssetoutinitandtheproductstestedinthiswaydeclaredfreeofsuspicionofcaus-ingcancer.Thereforethe“KIcriterion”isseldomusednowasevidenceofbiosolubility.
1 The KI value is derived from the difference in the mass contents of the oxides of the elements Na, K, B, Mg, Ca., Ba and
twice the Al oxide content
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Sinceabouttheendofthe1990sonlyappropriatelytestedbiosolubleSMFinsulationmaterialshavebeenavailableonthemarket.Thereisnorisktohealthfromthesematerials.InthecaseofSMFproductsinstalledearlier(un-tilabout1998)necessaryrenovationmeasures,inthecourseofwhichfibrescanbereleased,shouldbeundertakenwithcautionandwithgoodventila-tionduringtheworks.TRGS(technicalrulesforhazardoussubstances)no.521describestheprotectivemeasuresthatmustbetakenduringdemolition,renovationandmaintenanceworkwitholdmineralwool.
SMFscanthereforebeclassifiedasfarlesshazardousthanasbestosfibres.TodatetherearenostudieswhichindicateaclearlinkbetweencancerinhumansandanincidenceofSMFpollution.Thefollowingreasonsmaybesignificant:
Mineralwoolinsulationproduceslessfibredustthancomparableas-bestosmaterials.Thisisevidentbothintheworkplaceandininvestiga-tionsintheindoorenvironment.Afibre-relatedcancerriskcouldnotbeproveninthemineralwoolinsulationindustry,whereasitisconsideredprovenintheformerasbestosindustry.
Thelengthwisesplittingoffibresobservedinasbestos,whichincreasesitsdanger,isnotaconcernwithsyntheticmineralfibres.
Theso-calledbiopersistence(i.e.thetimeittakesforafibretobreakdowninthebody)ofSMFshasbeenshortenedstillfurtherinrecentyearsthroughsuitablematerialcomposition.
SMFscanhaveanirritanteffect.ThusSMFsreleasedfromacousticceilingconstructionscanleadtoirritationsoftheeyesandtheupperrespiratorytractsinpeoplespendingalongtimeinthecontaminatedroom.Thiscanbelargelyavoidedwithacousticceilingconstructionsbyinstallingafilterlayer.
Mineralwoolproductsshouldnotbecomparedwithasbestos–eitherintermsofareasofuseorofsignificancetohealth (seeboxpage --).Forprecautionaryreasons,whenusingmineralwoolproductsinindoorspacescareshouldbetakentoensurethatfibresdonotcomeintoopencontactwiththeairinsidetheroom(e.g.inthecaseofacousticceilingsbyinstallingafilterlayer).Thereisnoreasononhealthgroundstoremovecorrectlyinstalledmineralwoolinsulation.Innew-buildstheuseofmineralwoolproductswiththeenvironmentlogoortheRAL[GermanInstituteforQualityAssuranceandCertification]“Mineralwool”markisrecommended.
Are synthetic mineral fibres as dangerous as asbestos?
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B-7 Biological substances
Aswellasthechemicalandphysicalairpollutantsdescribedintheprevioussections,substancesofbiologicaloriginalsoalwaysoccurinsideschools.Thisisbasicallyunavoidable,asmostofthesesubstancesareeitherbroughtinbythoseusingtheroomorentertheroomwiththeoutsideairduringventilation.
Pollutionfrombiologicalsubstancesinschoolbuildingsdifferssignificantlyfromlivingspacesonsomepoints,whileonothersthereisnosubstantialdistinction.
Thus,incontrasttohomes,noteworthyinfestationswithhousedustmitesareonlyseldomtobeexpectedinschools(incosycorners,forexample).Biologicalwastebinswithkitchenandgardenwastearerarelyfoundinsideschoolsasarule.However,foodremainsleftlyingaroundarenotinfre-quentlythecauseofmicrobialcontaminations.
Animal allergensontheotherhandplayapartinbothprivatehouseswheretherearepetsandinschoolbuildings,astheyarebroughtfromhomebythepupilsandteachers.Studiesinschoolshaveshownthatrelevantcon-centrationsofpetallergenscanoccurthere,especiallyfromcatsanddogs.Thesecanbefarhigherthantheconcentrationsdetectableinhomeswherepetsarekept.Theallergensarebroughtinontheclothesofpeoplewholiveinhouseswithpetsorhaveregularcontactwith;them.
Theallergenscanbefoundonallsurfaces,suchastables,chairs,etc.orinhousedust,whichaccumulatesespeciallyreadilyincarpeting.Hardfloorcoverings,whichcanbewashedandthereforecollectlittledust,arethere-foremucheasiertokeepfreeofallergensthancarpets.However,dustismoreeasilyraisedfromhardfloorsiftheyarenotcleanedregularly,whichiswhythetypeofflooringandfrequencyofcleaningmustnotbeconsid-eredinisolationfromeachother.
Insomeclassroomsitisalsousualtokeepplantsoranimalsincages.Thiscancauseallergicreactionsinafewpeople.Ifcagedanimalsarekept,thereistheadditionalproblemthatthestrawandanimalfoodalsocontainmicro-organisms,whichcanbereleased.Likewisethesoilinplantpotscanbeasourceofmould(seebelow).
Afurtherproblemwhichcanaffectallbuildings,regardlessofthetypeofuse,isdamp-relatedmould damage.Ifasufficientlyhighlevelofdampispresentoverafairlylongperiod,mouldandothermicro-organisms(bacteria,yeasts,protozoa)willgrowinsideoronmostbuildingmaterials.Althoughattacksofmouldpresentaprobleminmanyschools,theywillnotbeexaminedindetailintheseGuidelines,astherearealreadytwosetsof
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guidelinesfromtheFederalEnvironmentAgencywhichaddressthisissue(FederalEnvironmentAgency2002and2005,seereferenceinChapterIII).Theprinciplescitedintheseguidelinesonthedetection,evaluationandremediationofsourcesofmouldinindoorareasarealsovalidforschoolbuildings.
Thecausesofexcessivemoistureandconsequentlyofmouldgrowthinschoolscanvaryconsiderably.Owingtopoorconstructiondampfromout-sidecanpenetrateintothebuilding,e.g.moisturefromtheground,ifcellarwallshavenotbeenmadesuitablywatertight,rainwaterifroofsleakandheavyrainiffacadesaredamaged.Watercanescapeinsidethebuilding,e.g.ifpipesorhosesbegintoleak.Withexcessivehumidityinthebuild-ingand/orstructuralcomponentsattoolowatemperature,condensationcanformonthesurfacesoffittings.Inthislastcaseitisoftennoteasytoestablishthecause,becausewhetheracomponentistoocoldasaresultofstructuralfailingsorbecauseofinadequateheating,whetherhighhumidityhasarisenthroughinsufficientventilation,orperhapsasaresultofasyetunidentifiedmoisturedamagetothebuilding,canmostlyonlybeestab-lishedbymeansofreadings,whichmustbetakenandinterpretedbyex-perts.TheFederalEnvironmentAgency’sguidelinesonmouldremediation(“Schimmelpilz-Sanierungsleitfaden”,UBA2005)containdirectionsforthesystematicinvestigationofthecausesofattacksandfortheirremediation.
Inadditiontomouldbacteriafromavarietyofsourcesalsooccurinindoorenvironments.Onesourceofbacteriaistheusersoftheroom.Allhumansarecolonisedonthesurfaceoftheskinandintherespiratorytractbyvari-ousphysiologicallyoccurringbacteria(e.g.coagulasenegativestaphylocci,micrococci,andcorynebacteria).Thesearealsoemittedintotheairasaresultofmovementorbyspeakingandcoughing,whichiswhybacteriaarealwaysdetectableintheairofroomsthatareinuse.Thisaircontaminationisunavoidableandunproblematic,exceptintherarecaseswhensomeonecolonisedbyorillfrompathogenicmicro-organisms(e.g.tuberculosisbac-teria)isintheroom.However,asairisanunfavourablehabitatformanyoftheseorganisms,theymostlyonlysurviveforashorttime.
Bacteriacan,however,alsogrowwherethereismoisturedamageindoors,butmostbacteriarequirehighermoisturelevelstogrowthanmould.Actinomycetesareoftendetectedwherethereismoisturedamage.Likemouldthesebacteriaformmyceliaandsporesandwerethereforeprevi-ouslyknownasrayfungi(actino=ray,mycetes=fungi).Someactinomyc-etescanproduceapowerfulodour(musty,earthy,mouldy).Thespectrumofvarietiesofactinomycetesoccurringwithmoisturedamageandtheirsignificanceforhealthisthesubjectofongoingresearchatpresent.Withremediationmeasurestocuredampandmouldattacksthegrowthofbacte-riacanalsobeprevented.
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Humidifiers,indoorwaterfountainsandold,poorlymaintainedair-condi-tioningsystemswithintegratedrotatingsprayhumidifierscanbeanothersourceofbacteria.Certainbacteria,e.g.typesofthepseudomonasspecies,canmultiplyveryeasilyinthepartscarryingwater.However,inschoolstheuseofsuchequipmentisgenerallysuperfluous,asthehumidityinclassroomsnormallyinintensiveuseishighenough,owingtothemoisturegivenoffbytheoccupants.
Aquitedifferentproblemcanariseinconnectionwithshowersinsportsfacili-tiesandchangingrooms.Insomecircumstanceslegionella,whichcanmulti-plyespeciallyeasilyinatemperaturerangeof25–45oC,canoccurinthehotwaterinstallation.Legionellaisthereforemainlyaprobleminlargerbuildingswithlongrunsandperiodiclengthystagnationofthewaterinthemainssys-tem.Topreventthegrowthoflegionellathecoldwatershouldalwaysbecold(<20oC)andthehotwaterhot(60oCandatleast55oCwhenitreachesthetap).Areductioninhotwaterinlettemperaturetobelow55oC(e.g.tosaveenergy)shouldbeavoided.Theonlyremedyforanincidenceoflegionellaisathoroughanalysisofthesystemwithregardtothefactorsencouragingitandifnecessaryariseinhotwatertemperaturetoatleast55oCwhenitreachesthetap,aswellaspossiblestructuralalterationstothemainswaterpipeslead-ingtothem,sothatdeadspacesorstagnationzonesarelargelyavoided.Innewinstallations,aswellasthegeneraltechnicalstandards,theregulationsintheDVGW(GermanTechnicalAssociationforGasandWater)factsheetW551forpreventinggrowthoflegionellashouldbeobserved(seealsoPartA-4).
Outbreaksofheadliceinchildrenarearecurrentprobleminschools.Control-lingoutbreaksofheadlicerequiresclosecooperationbetweenparents,schoolandhealthagency.Everycaseoflicemustbereportedbynameinwriting(byletter,faxore-mail)tothehealthagency,inaccordancewithArticle34oftheProtectionagainstInfectionsAct(IfSG).Apreciseplanofactionshouldbeputinplacefortheprocedureintheeventoftheoccurrenceoflice(seetheschoolsspecimenhygieneplaninAppendixIfordetails).
Thehealthassessmentofsubstancesofbiologicaloriginisverycomplexandmustthereforebeconsideredinaslightlydifferentway.Sensitivitiesandaller-gies,irritanteffects,infections,intoxications,unpleasantodoursanddiscom-fortmustberegardedaspossibleeffects.
Substanceswithanexclusivelyallergeniceffectonlyinducesymptomsinaller-gicpeoplewithasensitivitytothecorrespondingallergen.Withinschoolsthisappliesmainlytoallergensoriginatinginanimals.Wherethesearesuspectedtheallergologististhebestpersontogivefurtherhelp,asitisusuallynoprob-lemtodiagnoseanallergytoanimalhair,cockroachesorhousedustmitesbymeansofmedicaltests.
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Itisnotalwayseasytotakecountermeasureswhentypicalsymptomsoccuratschoolinindividualpupilsorevenstaffwithacorrespondingallergy.Contaminationcanbereducedthroughregularthoroughcleaningandbyusingcertainfurnishingmaterials,suchashardfloorsinsteadofcarpets.Itisnotpossibletopreventpupilsandteachersfrom“bringing”therelevantallergensfromhome.
Assessingthehealthrisksofmoulddamageissignificantlymorecom-plicated.Itisknownfromscientific,epidemiologicalstudiesthathealthproblemscangohand-in-handwithmoisturedamageandmouldgrowthintheindoorenvironment.Forthisreasonmouldgrowthindoorsshouldberegardedasahygieneproblemandshouldnotbetolerated.Neverthe-less,thediscoveryofasourceofmouldinsidethebuildingshouldnotbeequatedwithanacutehealthrisktoitsusers.
Thefundamentalassumptionisthatmanytypesofmouldcancauseal-lergicsymptomsiftheyhaveasuitablyintensiveorlong-terminfluence.Onthebasisofcurrentknowledgeintoxicationscanbepracticallydisre-garded,astheconcentrationsofmycotoxins(thetoxicmetabolicproductsformedfrommoulds)tobeexpectedinindoorareasaresignificantlybelowtheconcentrationsconsideredacutelytoxic.However,unspecificir-ritanteffectsofsomebioaerosolconstituents,whichcanleadtosymptomssuchasirritationsofthethroatandmucousmembrane,areapossibility.
Infectionswithmouldonlypresentadangertopeoplewithasuppressedorweakenedimmunesystem.Thisatriskgroupincludesmainlypeoplewhohaveundergonebonemarrowororgantransplants,andpatientsintheacutephaseofchemotherapyoronlong-termhighdosesofcorticosteroids(substanceshavingthesameeffectascortisone).
Theextentoftheactualhealthriskfrommouldisdependentonanumberoffactors,includingtheextentandtypeofdamage,butalsoontheindi-vidualsensitivityofthepersonlivinginorusingtheroom.Atpresentthescientificknowledgeavailableisunfortunatelyinadequateformakingaquantitativerecordofthedamagewithregardtothemedicalrisk,andtherearealsonomedicalteststhatcanattributethesymptomsunequivo-callytotheexistenceofmoulddamage.
ThelatestrecommendationfromtheRobertKochInstitute,„Schimmelpilz-bildunginInnenräumen–Befunderhebung,gesundheitlicheBewertungundMaßnahmen“[“Mouldformationinindoorenvironments–investiga-tionintothefindings,healthevaluationandmeasures”](Bundesgesundhbl-Gesundheitsforsch-Gesundheitsschutz50:2007,pp.1308–1328),providesassistancewithasemi-quantitativeriskassessment.
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Inconclusionitcanbesaidthatsourcesofmouldshouldberemovedorremediedforreasonsofpreventativehealthcare,i.e.theprecautionaryprinciple,bywhichcontaminationsshouldbeminimisedbeforeillnessoccurs(theminimisationrule),shouldbeapplied.
Asexplainedabove,althoughbacteriaoftenoccuraroundmoisturedam-age,littleisunderstoodabouttheirrisktohealth.Thereareafewstudiesinwhichtheassumptionismadethatimpactsonhealthareduetothepres-enceofbacteria.Thereforetheminimisationruleshouldalsoapplyforpre-cautionaryreasonsinrespectofthegrowthofbacteriainmoisturedamage.Thebacteriaandothermicro-organismsarealsodestroyedbytheremedia-tionmeasuresindicatedformould,sothatnofurtheractionisnecessary.
Toavoidpossiblehealthrisksfrommicro-organismspropercleaningofsanitaryareasshouldofcoursetakeplaceinschoolsaswell(cf.SectionA-2).
Anotherriskthatcanarisefrombacteriaandvirusesisthetransmissionofinfectionsfromonepersontoanotherthroughdropletordirectcontacttransmission.However,thetransmissionofillnessessuchasinfluenza,scar-letfever(streptococcuspyogenes)andwhoopingcough(bordetellapertus-sis)isnotaproblemspecifictotheclassroom.TopreventthesetherelevantguidancefromtheRobertKochInstitute(e.g.HinweisefürÄrzte,LeitungenvonGemeinschaftseinrichtungenundGesundheitsämterzurWiederzulas-sunginSchulenundsonstigenGemeinschaftseinrichtungen[Advicefordoc-tors,managersofcommunityinstitutionsandhealthagenciesonreadmis-siontoschoolsandothercommunityinstitutions],updatedJuly2006.FirstpublishedinBundesgesundheitsbl44(2001):830–843)shouldbeobservedandthechildreninstructedingoodhandhygieneandcoughetiquette.
B-8 Radiation (radon)
Manhasalwaysbeenexposedtonaturalradiation.Thisradiationismadeupofexternalradiationfromspace(cosmicradiation)andnaturalradioac-tivesubstancesinrocksandsoils(terrestrialradiation)aswellasinternal
Airhumidifiersandalsoindoorfountainscancontributetothespreadofgerms,if equipment is not regularly cleaned and the humidifier water not regularlychanged.Becauseoftheriskofmicrobialcolonisationthereshouldbenohumidi-fiersorindoorfountainsinschools.
Are air humidifiers a hazard inside schools?
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radiationfromnaturalradioactivesubstancestakeninwithfoodorfromtheair.
Asubstancethatarisesfromtheradioactivedecayofnaturallyoccurringuraniumorthoriuminrocksistheradioactivenoblegasradon.Itisanaturalradioactivenoblegaswithahalf-lifeof3.8dayswhicharisesfromtheradioactivedecayofuranium(half-life4.5bn.years)oritsdaughterproductradium-226(half-lifeapprox.1600years).Itiscolourless,tastelessandodourlessandoccursparticularlyinareaswithgraniterock.Asagasitmoveseasilythroughthesoilandpenetratesfromthesoilairthroughcel-larwallsandfoundationsintobuildings.Ifradonescapesfromthegroundintotheatmosphereitisveryrapidlydispersedintheoutsideair,sothatsignificantlylowerconcentrationsarepresentintheoutsideairthaninsoilair.Normalconcentrationsintheoutsideairarebetween10and30Becquerel(Bq)/m3(1Bqdenotesoneradioactivedisintegrationpersecond).InGermanytherearesomeregionswithaparticularlyhighradoncon-tentinthesoil.TheseincludesomepartsoftheBavarianForest,theBlackForest,theFichtelMountainsandtheErzgebirge(OreMountains)aswellastheEifelregion.(TheFederalOfficeforRadiationProtection’s“radonmap”(availableat:http://www.bfs.de/de/ion/radon/radon_boden/radonkarte.html)providesinformationontheradon-contaminatedregionsofGermany.)
Owingtoitsalpha-radiatingdecayproductsinhaledradonleadstoheight-enedradiationexposureofthelung.Thisincreasestheriskoflungcancer.AftertobaccosmokeradonisregardedasthesecondmostcommoncauseofcasesoflungcancerinGermany.Theleveloftheriskofdevelopinglungcancerriseswiththeleveloftheconcentrationofradoninindoorairandwiththelengthoftimespentintheroom.Accordingtotheresultsofepi-demiologicalstudiesoftheresidentialpopulationofSweden,EnglandandGermanytheriskoflungcancerincreasesbyaround10%whentheradonconcentrationrisesby100Bqperm3.Thismakesradonthemostimportantindoorcarcinogen.
Inthecaseofnew-buildsinradon-contaminateddistrictsappropriatestructuralmeasuresshouldbeincludedinthedesigntoreducetheradonriskinsidethebuildings.Forexample,groundsourceheatsystemssuchasthoselikelytobeusedincreasinglyinenergy-efficientnewschoolbuildingsinfutureshouldbesowellsealedthatradonfromthesoilcannotentertheheat-exchanger.Inexistingbuildings,intheviewoftheFederalOfficeforRadiationProtection,measuresshouldbecarriedoutforconcentrationsabove100Bqperm3,bearinginmindthepossiblerelationship.Increasingtheventilationintheroomisacheapmeasurethatcanbecarriedoutintheshorttermtoreduceradonconcentrations.
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PART C: Structural and indoor climate requirements
Thefollowingsectionsaddressthehygiene-relatedrequirementswhichmustbelaiddownforconstructionproductsandmaterialsusedinfixturesandfittingsforindoorareasinschoolconstructionorrefurbishmentprojects,fol-lowedbygeneralaspectsrelatingtoindoorclimateandventilation.
C-1 Structural requirements, fixtures and fittings for indoor areas
Since1989therequirementsforconstructionproductswhichrelatetohealthandenvironmentalprotectionhavebeenanchoredinlawintheECConstructionProductsDirective(Directive89/106/EEC).InGermanytheDirectivewasimplementedbytheConstructionProductsActin1992.Althoughbothrulingslaydowntheframeworkforhealthprotection,theirpracticalimplementationinstandardsandregulationsisstillpartlybeingworkedout.TheCommitteefortheHealth-relatedEvaluationofBuildingProducts(AgBB)whoseofficeislocatedintheGermanFederalEnvironmentAgency(UBA)wasfoundedin1997withtheaimofminimisingemissionsofchemicalsfromconstructionproducts.InthefollowingyearstheAgBBdevelopedaschemeforevaluatingemissionsfromvolatileandsemi-volatileorganiccompounds.Between2002and2004this“AgBBEvaluationScheme”wastestedwithaviewtopossiblyimplementingitinpractice.Theevalua-tionschemeclosesamajorgapwhenverifyingthefitnessforuseofacon-
structionproduct.Aconstructionproductisconsidered“fitforuse”ifitsatisfiesthetechnicalrequirementsanddoesnotimpairthehealthoftheindoorusers.
Likeothertestingcriteria,includingforexamplerecipespecificationsandtheexclusionofcertainhazardoussubstances,theAgBBschemealsoformsanintegralpartoftheprinciplesforevaluatingthehealtheffectsofconstructionproductsinindoorareas,whichservetheGermanInstituteforConstructionEngineer-ing(DIBt)asabasisforgrantingnationaltechnicalapprovals.TheGermanMarkofConformityisthelabelforconstructionproductswithnationaltechnicalap-proval(seeFigure1).
Bild1:„Ü-Zeichen“(Muster,
Inschriftenkönnenvariieren)
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Theadditionalnote“EmissionscheckedforconformitywithDIBtcriteria”indicatesthatanexaminationaccordingtotheAgBBschemehasbeencar-riedout.ThefirstconstructionproductwhichtheDIBtapprovedafteranemissionstestin2005wasatextilefloorcovering.Sincethentheinstitutehasapprovedrubber,PVCandlinoleumfloorcoveringsandlaminatefloor-ings,usingtheemissionstest.Moreconstructionproductswillfollow.
IncomparisontotheAgBBscheme,thespecificationsfortheBlueAngellabelforemissionsfromvolatileorganiccompoundsarestricter,thatis,theproductsmustcontainmuchlowerconcentrationsofthetestvalues.Inaddition,strictrequirementsalsoapplytoothersubstances,e.g.formalde-hyde,whichtheAgBBschemedoesnottakeintoaccount.
Inconclusion,itcanbesaidthatconstructionproductswhichhavepassedthehealth-relatedassessmentaccordingtotheAgBBschemesatisfythestatutoryminimumrequirements.TheBlueAngelincorporatesfurtherre-quirementsregardingenvironmentalandhealthprotectionandisavailableforconstructionproductswhichhavenotyetbeentestedinaccordancewiththeAgBBscheme.
C-1.1 Building shell
Theusualconstructionproductsforthebuildingshell(mineralbuildingmaterials,woodandmetal)donotposeanydangertotheoccupantsandbuildingusers.Byanalogythisalsoappliestomanyrenderings,paints,wallboardsandceramictiles.However,someoftheseconstructionproductscontainconstructionchemicaladditiveswhichmustbeconsideredsepa-rately.
Todayselectinglow-emissionconstructionproductsismorenecessarythanever.Stricterrequirementsforsavingenergymeanthatbuildingenvelopesaremadeincreasinglyairtight.Withoutadequateventilationtheeffectcanbetocreateanaccumulationofchemicalandbiologicalsubstancesreleasedintotheindoorair.Using low-emission constructionproducts aswell as increasing the ventilationcanhelptopreventthis.ProductswiththeÜMarkhavebeentestedforpollutantsandfulfilthestatutoryminimumrequirements.
ProductswiththeBlueAngelmarkandaddednote“weilemissionsarm”(lowinemissions)or“weilschadstoffarm”(lowinhazardoussubstances)areevenmoresuitable.
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Thespecificpropertiesofbuildingmaterialsusedforthebuildingshellsofschoolsareoutlinedbelow.Particularlyproblematicmaterialsintermsofhygieneareaddressedbywayofexample.
Concreteisbyfarthemostcommonbuildingmaterialinbuildingshells.Itconsistsofcementasabindingagentandnaturalaggregatessuchassandorgravel,whichhardentoformastone-likemasswhenmixedwithwater.Bothconcreteandcementandcertainaggregatesarestandardisedortestedfornationaltechnicalapprovaliftheydeviatefromthestandard.Inthese“certificatesoffitnessforuse”possible,harmfuleffectsonhealthortheenvironmentareconsidered.
Bricks,lime-sand bricks,concrete blocksandporousconcreteblocksandthewallandrenderingmortarrequiredtobuildwiththemareoftenusedfortheexternalmasonry.Wallbricksareformedfromclay,sand,limestoneandwater,towhichsmallquantitiesofauxiliarymaterials,e.g.porosityenhanc-ingagentsareadded,andfiredattemperaturesofover1,000oC.Inthefiringprocessorganicpollutants,alsointroducedintothe“mouldedbricks”whenresiduesareused,aredestroyed.Thereforeoncefired,bricksdonotposeanyhealthriskatallasarule.
Lime-sandbricksareproducedfromlime,sandandwaterandhardenedattemperaturesof160-220oC.Giventhesebasematerials,theydonotcauseanyhealthproblemseither.Similarly,theinformationonconcretegivenaboveappliestoconcreteblocksandporousconcreteblocks.Heretoothegeneralpointshouldbemadethatthemajorityofwallbricksareregulatedbystandards,andthatdeviationsfromthestandardsaredealtwithaccord-ingtotheproceduresfornationaltechnicalapprovaldescribedabove.
Eventhegasconcreteandporousconcreteblocksinpopularusetodayaspartofenergysavingimprovementsinconstructionarefreeofadditivesandposenohealth-relatedrisk.Thisisnotthecasewithexternalwallswhicharebuiltusinguprights(wood,usuallysteelinschools)withcavitiesinbetweeninordertosaveenergy.Thesearethenfilledwithinsulatingmaterialsandhaveonlyplankingmadeofplasterboardorsimilarsubstanc-esandavapourbarrierbeneaththisattachedontheinside.Insulatingma-terialscancontainchemicalslikeformaldehydeand/oralreadybecontami-natedbymicrobesbeforedeliveryonsite.Thisdoesnotnecessarilycauseindoorairpollutionlatersincethevapourbarrier,provideditissealedandinstalledcorrectly,alsohelpstopreventpollutantsenteringtheindoorair.
Problemsonlyarisewhencracksandleaksemergeinthewalls,allowingsubstancesfromthecavitiestogetintotheindoorair.Problemsalsooccurifdamppenetratesthecavitiesduringconstructionorlateronandcan-notdryoutanymore.Microbescanthengrowconcealed,whichcanhave
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detrimentaleffectsonthehealthoftheusersoftheindoorareas(cf.SectionB-7).Therefore,particularcaremustbetakenineverydaypracticetoensurethatnodamageiscausedbydampgettingintocavitywallconstructions.
Mortarforwallsandrenderingismadefrommaterialsbondedwithcementorlimewhichhardenwhenwaterisadded.Aswellasaddedmaterialssuchassand,gravelorlimestone,arangeofauxiliarymixingmaterialsisused,butsincetheproportionsaresmall,theyareratherinsignificantasregardshygiene.
Woodisthebuildingmaterialmanhasusedforlongestandwhich,asarenewablerawmaterial,hasalwaysbeenavailablealmostanywhere.Sincewoodisflammableandsusceptibletoanimalandplantpestshowever,itisimportanttofollowcertainruleswhenusingwoodinconstructiontopreventinfestationfrominsectsorfungiwhichdestroywood.AccordingtoDIN68800-2“Woodpreservation–Part2:Preventiveconstructionalmeas-uresinbuildings”,todaybuildingscanbeconstructedinsuchawaythatload-bearingtimbercomponentsandbraces,includingtheroofstructure,donothavetobetreatedwithwoodpreservativesiftherelevantcompo-nentsarevisibleorpermeabletoliquids,gasesandinsects.Thetimberscanbepre-treatedbyphysicalprocesses(thermaldrying)sothatonlyasmallamountofmoistureremainsinthewood.Moreover,ifthisremainsthecaseinthebuildinglateron,itwillatleastbeverydifficultfororganismswhichdestroywoodtogrowthere.Itishowevertruethatdispensingwithchemi-calwoodprotectionrequirescarefulplanningandexecutionandcanlimitthechoiceofmaterials.
Iftheparticularconstructiondemandsofabuildingmeanthatpreventivetreatmentwithwoodpreservativescannotbeavoided,onlytechnicallyap-provedwoodpreservativescanbeusedonload-bearingcomponentsandbraces.
Withintheframeworkoftheapprovalproceduresforthesekindsofmateri-als,theireffectsonhealthandtheenvironmentaretestedandassessed,tak-ingaccountoftheirintendeduse.
Itcanbepresumedthattechnicallyapprovedwoodpreservativesposenoriskstothebuildinguserswhenusedcorrectly.
Withcomposite wood panels(e.g.particleboardorOSBpanels)whicharemainlyusedforlargeareas(e.g.asflooringpanels),aboveallthereleaseofformaldehydeemissionsshouldbeborneinmind(cf.SectionB-3).Nowadaysflooringpanelsareusuallygluedwithwaterproofadhesives(V100).Thesegluesemitlittleornoformaldehyde.Theproductsarealsoclearlylabelledfortheuserswiththe“E1”emissionsclassmarkforlow-formaldehydeorhave“formaldehyde-free”printedonthem.Withthe
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latter,isocyanateshavebeenaddedtothegluebutcannolongergetintotheindooraironcethegluehashardenedduringtheproductionprocess.Todaythelargestquantityofcompositewoodpanels(e.g.particleboardandplywoodwhichisnotgluedwithawaterproofadhesive)isstillgluedwithurea-formaldehyde-resin-basedadhesiveswhichcanmorereadilyemitformaldehydeovermanyyears(seealsoC-1.3).Formaldehydeemissionscanbereducedbymeansofcoatingsnotpermeabletoformaldehyde.WithOSBpanels,higher-orderaldehydesandcarboxylicacidsinparticularcanproduceunpleasantodoursintheindoorair.Nowadaysusingbiocidesincompositewoodpanels(V100G)isnolongerpermittedinindoorareas.
Withmetalsusedinbuildingshellsadistinctionmustbemadebetweenironorsteelandnon-ferrousmetalssuchasaluminium,zincorcopper.Theyposenoproblemasregardshygienesincetheyemitnopollutantsintotheindoorair.However,thisappliestothemetalsthemselves,nottotheircoat-ingsorvarnishes.Essentially,materialswhicharepowdercoatedexfactory(e.g.radiators)areemission-free.
C-1.2 Extensions and conversions
Emissionsfromconstructionproductsdonotalonedetermineindoorairquality.Materialsusedinfixturesandfittingsalsoplayapart.Therangeofproductmaterialsusedinindoorareasisjustasvariedasthatofthemateri-alsusedinbuildingshells.Itisalsothecaseherethatusingeco-friendlyandlow-emissionproductscannoticeablyreduceindoorairpollution.
Therecommendationslistedtogetherbelowcanserveasinitialinformationforworkdonebyspecialistfirmsandin“self-help”situations.Obviously,aswellastheiradvice,therecommendationsforuseandmanufacturer’sinstructionsonthepackagingmustbefollowed.
Besidestechnicalapprovalwhichregulatesthehealth-relatedfitnessforuseofconstructionproducts,theBlueAngelindicatesparticularlylow-emissionconstructionproductsandfurnishingsusedinindoorareas(cf.Table7).Inordertodeterminethehealtheffectsofvolatileorganiccompounds(VOCs),theBlueAngelalsousestheschemeforassessingconstructionproductsintermsofhealth(AgBBscheme)withmanyproducts.However,therequire-
Extensionsandconversionsinschoolbuildingsshouldprimarilybeundertakenbyspecialistfirms.Sinceteachers,parentsandpupilsareincreasinglyresortingto“selfhelp”inviewofthefinancialsituation,expertsshoulddefinitelybecon-sultedbeforethiskindofworkisbegun.
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mentsforthemaximumvaluesforTVOCs(totalvolatileorganiccom-pounds)andSVOCs(semi-volatileorganiccompounds)aremuchstricter.WiththesetheBlueAngelreducestheamountofpollutantspermeatingtheindoorairandcontributestowardspreventivehealthcare.
Tabelle 7: The Blue Angel for low-emission products
Criterias for Blue Angel label Awarded products
RAL-UZ 12aLow-emissionpaintsandvarnishes
Clearandcolouredpaintsandvarnishes,glazes,primers,radiatorpaints,etc..
RAL-UZ 38Woodandwood-basedproducts
Furniture,parquet,laminate,linoleum,panels
RAL-UZ 76 CompositewoodpanelsParticleboard,fibreboard,floorboards
RAL-UZ 102 WallpaintsEmulsionpaints,latexpaints,Mixingpaints,silicateemulsionpaints
RAL-UZ 113Floorcoveringadhesivesandotherinstallationmaterials
Adhesivesforflexiblefloorcover-ings,parquet,fillers
RAL-UZ 117 Upholstery Chairs,armchairs
RAL-UZ 119 Mattresses Springcoilandfoammattresses
RAL-UZ 120 Flexiblefloorcoverings Rubberfloorcoverings,linoleum
RAL-UZ 123 Sealantsforindoorareas Silicones,acrylates
RAL-UZ 128 Textilefloorcoverings Carpets
Furthermore,therearemorelabelsoriginatinginprivateinitiativesandusedbyvariousproducersinternationally.Theseinclude“natureplus”fromnaturepluse.V.(environmentorganisation)forvariousconstructionprod-ucts,‘GUT’fromGUTe.V(theorganisationoftheEuropeaneco-friendlycarpetproducers),“EMICODEEC1”fromtheGemeinschaftEmissionskon-trollierteVerlegewerkstoffee.V(AssociationfortheControlofEmissionsinProductsforFlooringInstallation)andthe“ScandinavianTradeStandards”.Withtheselabellingsystems,thetestinginstitutionsalsodetermineemis-sionsaccordingtoENorISOstandardsorrelatedmethods.
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Varnishes:
Conventionalalkydresinvarnishescancauseconsiderableindoorairpollutionduetotheirsolventcontent(35-55%w/w)andduetothefis-sionproductsofthedryingoils(aldehydesandcarboxylicacids).Thejointrecommendationforusing“solvent-reducedconstructionvarnishes”,publishedbytheWorkgroupforInstitutionsforStatutoryAccidentInsur-anceandPreventioninConstruction(Bau-BG),theGermanpaintersandvarnishersguild,thepaintandvarnishindustryandtheGermanFederalEnvironmentalAgencyamongotherscomestotheconclusion:“Takingtheirrespectivepropertiesasawhole,dispersionvarnishesareatechnicallyequivalentalternativetoconventionalalkydresinvarnishesformostareasofapplication.Furthermore,becauseoftheirreducedsolventcontent,dis-persionvarnishesaregenerallymuchmorecompatiblewithhealthandtheenvironmentandthereforeusingtheseispreferabletousingconventionalalkydresinvarnishes.”Morerecentinvestigationsontheirfitnessforuseandemissionsperformanceconfirmthisstatement.
ManydispersionvarnishescarrytheBlueAngelmark.Foralongtimethetriedandtestedalternativestoconventionalvarnisheshavebeen“low-pol-lutantvarnishes”withtheRAL-UZ12aeco-label(max.2–10%w/wsolventcontent),whichusuallycontainalcoholsandGlycoletherinplaceofaliphat-icandaromatichydrocarbons.Duetotheirlowsolventcontent,comparablelow-pollutantvarnishescausenoticeablylessindoorairpollution.
Beforepaintingandvarnishing,acheckshouldbemadeonwhethertheworkrequiresusingvarnishes,oremulsionpaintscouldbeused instead.Emulsionandlatexpaintsarethepaintssuitableformineralsubsurfaces(wallsandceilings).
Low-pollutantvarnishesorwoodglazeswiththeBlueAngellabelarethemostsuitableforprotectingthesurfacesofnon-load-bearingtimbersinin-doorareas(livingareas).Low-pollutantvarnishesforprotectingthesurfacesofwoodencomponentsorobjectsexposedtotheweatherarealsosold.
Surfacetreatingagentswithahighsolventcontentshouldnotbeusedforvarnishingparquet.Water-basedsurfacetreatingagents(waterseals)basedonacrylicorpolyurethaneresinshouldbeusedinstead.
What must be noted when using varnishes in renovations?
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Wall paints, (emulsion paints, silicate paints):
Emulsionpaintsaregenerallyheldtobeeco-friendly.Basicallythisistrueforthemainingredients:water,fillers(e.g.chalk),titaniumdioxideasapigment(provideditisproducedaccordingtotheECDirective)andbind-ers.However,emulsionpaintscannotbeproducedfromtheseingredientsalone.Useableemulsionpaintsneedvariousadditivesaswellandtheycontainpreservatives.Ifalotoftheseareused,theycancauseindoorairpollutionundercertaincircumstances.Silicatepaints,alsocalledmineralpaints,containwaterglassastheirbinderaswellasinorganiccolourings.Usingmodern(eco-friendly,low-emission)emulsionpaintsorsilicatepaintscansignificantlyreduceindoorairpollution.Theseemulsionpaints,alsotermed“ELFpaints”(emissionandsolventfree)havebeensoldbythepaintandvarnishesindustryforseveralyearsnow.Theyhavenotyetbecomeestablishedonthemarketbecausetheyaremoreexpensivethanconven-tionalemulsionpaints.
Floor covering adhesives:
Likevarnishes,floorcoveringadhesivesconsistoffourgroupsofmateri-als:binders,solvents,fillersandadditives.Todaymodernfloorcoveringadhesivesusuallycontainonlywaterastheirsolvent.However,theemis-sionsfromtheseadhesivescandifferintermsoftheirdifferentproductionprocessesandadditives.Forcertainbonds,forexample,parquetondifficultsubsurfaces,adhesivescontainingsolvents,evenadhesiveswithquitealotofsolvents,arestillusedtoday.Sometimes,usingtheseadhesivesinindoorareascanstillaffectpeople’shealthadverselyalongtimeaftertheirappli-
Emulsionpaintsaresuitablepaintsforcoveringlargeareasofwalls,ceilingsandfaçades.Usingvarnishesisnotnecessaryhere.
Paintsontheinsideofexternalcomponentsshouldnotadverselyaffectthewatervapourdiffusionperformanceoftheseexternalcomponents.
As farasprotectinghealthand theenvironment is concerned,only low-emissionwallpaintsshouldbeusedinindoorareas.Mattemulsionpaints,silkglossandglosslatexpaintsandsilicateemulsionpaintswhichhardlycontributetoindoorairpollutionwithvolatileorganiccompounds(VOCs)ordonotdosoatall(ELFpaints)havetheBlueAngellabel“weilemission-sarm”(lowinemissions)
Preservatives included in the contents declaration on the cans of water-basedpaintsshouldbenoted,inordertoprotectallergysufferers.
What should be considered when using emulsion paints (wall paints)?
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cation.Thereasonsforthiscanbethepoorconditionofthesubsurface(e.g.highlyabsorbentsubsurfaces),incorrectsubsurfacepreparationorhigh-boilingsolventsintheadhesiveswhichrequirealongtimetoevaporatecompletelybecauseoftheirlowvapourpressure.Topreventthisindoorairpollution,alreadyensuringattheplanningstagethatthefloorcoveringonthesubsurfacecanbelaidwithalow-emissionfloorcoveringadhesiveand,ifnecessary,includinglow-emissionfillerandprimer,isrecommended.
Thelow-emission“BlueAngel”eco-labelforlow-emissionfloorcoveringadhesiveshasbeeninexistencesinceJune2003.ThebasicawardcriteriaarebasedontheevaluationschemedevelopedbytheCommitteefortheHealth-relatedEvaluationofBuildingProducts(AgBB).TheaimoftheAgBBisauniform,comprehensible,health-relatedevaluationofconstructionproductsinGermany,withspecialreferencetoemissionsfromvolatileorganicsubstances.TheGemeinschaftemissionskontrollierterVerlegewerk-stoffe(GEV)(AssociationfortheControlofEmissionsinProductsforFloor-ingInstallation)alsoawardstheEC1markforrelativelylow-emissionfloorcoveringadhesives,forwhichtherequirementsarelessstrict.
Withfloorcoveringadhesivesbasedonemulsions,isolatedemissionscanbedetectedwhichdonotoriginatedirectlyfromthesubstancesthemselves,butaretheresultofreactions(secondaryemissions).Thesesubstancesarecarbonylcompounds(aldehydes,ketonesandorganicacids),someofwhichhaveonlybeenfoundaftertestslastingmorethan28days.Someofthesubstanceshaveverylowodour-thresholds,i.e.theycanbesmelledeveninlowconcentrationsandcouldthereforeberesponsibleforunpleasantsmellswhichinpracticeareusuallythemaincauseofcomplaint.Theoriginofthesesecondaryemissionscouldbelinkedtotheuseoftallresins(resinfrombeechtrees,isusedindustriallyinpaperadhesivese.g.)ortalloilsinadhesives.Thesecancontainunsaturatedfattyacidssuchaslinoleicacidandoleicacidwhichareknowntobeconvertedintothesubstancesreferredtothroughoxidationbyatmosphericoxygen.FloorcoveringadhesiveswiththeBlueAngelmarkcannotcontainoxidisableingredients.
Nowadays theadhesives industry sells solvent-free, low-emission floor coveringadhesives for all types of floor coverings (flexible floor coverings, carpets, par-quet).Givensuitablepre-treatmentofthesubsurface(e.g.filling),theseadhesivescanbeusedonall subsurfaces.Adhesive residues fromold coveringsmustberemovedbeforehand.
Which floor covering adhesives should be used?
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Floor coverings:
Floorcoveringsformthetoplayerofthefloor.Increasingly,concernsrelatedtoenvironmentalandhealthprotectionalsoplayapartintheirselectionbesidestechnical,functionalanddesignaspects.Itisoftennotenoughtoconsiderthefloorcoveringalonesinceitsemissionsperformancecanbeinfluencedstronglybythesubsurface,forexample,byabsorbentscreedwhichcanretainsolventsortheadhesivesapplied.Forthisreasontheentirestructureofthefloor,togetherwiththeunderfloor,thelayingtechniqueandmaterialshouldbeincluded.Onlyfloorcoveringswhichcanbedampwipedshouldbeusedifpossibleafternewbuildorrenovationsinschoolbuildings.
Textile floor coverings:
Textilefloorcoveringsshouldnotbeusedinschoolsbecauseofthecompar-ativelyhighcostofcleaningintermsoftimeandexpense(cf.SectionA-2).
C-1.3 Fixtures and fittings for indoor areas
Furniture,particleboardandotherproductsmadeofwood-basedmaterialsrepresentapotentialsourceofemissionsduetotheirnumberandtherela-
Asregardsdampwipefloorcoverings,thereisno“ideal”floorcovering.De-pendingontheintendedareaofuseandthenecessarystandardrequired,a selection shouldbemade from threedifferentproductgroups suchaswood/wood-basedproducts, flexibleandceramicfloorcoveringsthatwillenableittobeusedforthelongestpossibletime.Asregardsthecostofcareintermsoftimeandexpense,nogreatdifferencebetweentheseproductgroupscanbeexpected.
Floorcoveringsinclassrooms(notincorridors)aresubjecttoapprovalbytheGermanInstituteforConstructionEngineering(cf.C-1).ForthisreasonitisessentialtolookforthepresenceoftheÜmark(seeFigure1,SectionC-1)whenpurchasingfloorcoverings.
SincethenithasbeenpossibletoawardtheBlueAngelmark“weilemis-sionsarm”(lowinemissions)toarangeoffloorcoverings:rubberandlino-leumcoverings,parquet,corkandlaminate.
Ceramicfloorcoveringsshouldbeusedanywherewheretheymustprovedurablegivenconstant,heavyuseandfrequentcleaning(e.g.sanitaryfa-cilities,cf.SectionA-2).
Which floor coverings should be used in schools?
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tivelylargeareatheyoccupyinteachingareas.Thevarietyoftheproductsusedinindoorareasandthechemicalproductsusedintheirmanufacturehasincreasednoticeablyinrecentyears.Thusfurnitureandwood-basedmaterialscancontributetoindoorairpollutiontoaveryvaryingextent.
Wood-basedmaterials(particleboard,coatedparticleboard,woodcoreplywood,veneers,fibreboard)andproductsfromwood-basedmaterialssuchasfurniture,doorsandpanelsareamajorsourceofformaldehydeinindoorareas.Thereleaseofformaldehydeislimitedtothesekindsofparti-cleboardandotherwood-basedmaterialswhichhavebeenmanufacturedusingadhesivesbasedonurea-formaldehyderesins(cf.SectionB-3).Onlylow-formaldehydeorformaldehyde-freefurnitureproductsshouldbeusedinschools.
Withlong-livedproductssuchasschoolandofficefurniturewhichcanhaveaconsiderableeffectontheindoorairoveralongerperiodoftime,anindicationthattheproductsarelessharmfultohealthandtheenvironmentisenormouslyimportanttotheuser.Buildingontheresultsofearlierre-searchprojectsbytheGermanFederalInstituteforMaterialsResearchandTesting,extendedbasicawardcriteriaweredevelopedfora‘Low-emissionfurniture’eco-label.Thesebasicawardcriteriawhichstillapplytodayarebasedontheproductlifeoffurnitureitems.Anessentialrequirementlimitsemissionsfromfurnitureitemsintotheindoorair.
TheDeutscheGütegemeinschaftMöbele.V.(GermanFurnitureMakersQualityAssociation)awardsaqualitymarkforqualityfurniture(RALmark).Incontrasttotheeco-label,withRALlabels,itisfirstandforemostthematerialsused,theirtreatmentandprocessingandcompatibilitywiththeenvironmentandhealthwhicharetestedonthebasisofexistingstatutoryregulationsandtherelevantstandards.Theapplicationareaofthequalitymarkincludesschoolfurniture.
Purchasing items of school furniture which are largely made of woodshouldbebasedontherequirementsforawardingtheeco-labelRAL-UZ38(seeTable7,SectionC-1.2).
It is also recommended that, when purchasing furniture which is mademainly of materials other than wood, products which fulfil the require-mentsoftheGermanFurnitureMakersQualityAssociation(RAL-RG430)es-peciallyasregardstheirfitnessforuseanddurabilityshouldbeconsidered.
Inindividualcasesa“furniturepassport”isalsoavailablewhichgivesinfor-mationaboutthetestresultonpossibleemissionsfromtheproduct.
What should be considered when purchasing school furniture?
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C-2 Building climate
C-2.1 General physiological requirements
Humanbeingsrelyoncomplexregulatorymechanismstokeeptheirbodytemperatureconstantindependentlyoftheambienttemperatureasfaraspossible.Theyonlyachievethisaimofmaintainingaconstantbodytemperatureof37oCiftheheattheydevelopmatchesthetotalheattheygiveoff.Hypothermiaandoverheatingareunlikelytooccurifthebalancebetweenheatproductionandheatlossismaintainedandtherearenosub-stantialvariations.Thebody’sheatproductiondependsprincipallyontheperson’sactivitylevel(seeTable8).Heatexchangewiththesurroundingsisdeterminedaboveallbyheatlossthroughtheskin.
Table 8: A person’s metabolic heat production when resting or taking part in some typical activities
Activity Heat production, watt/person
Rest (basic metabolic rate) 80
Sitting activity (reading, writing) 100–125
Light activity (laboratory) 150
Moderately vigorous physical activity (climbing stairs etc.)
170–230
Vigorous physical activity (competitive sport, construction work)
400–600
Thefollowingfactorsinfluencetheheatexchangeofhumanbeingswiththeirenvironment:
Thermalconduction(e.g.throughcontactwithfurniture,floorsetc.)
Convection(heattransfer,e.g.viaaircurrents)
Evaporation(constantwaterevaporationthroughskinandmucousmembranes,occasionalevaporationthroughsweating)
Heatradiation(e.g.heatemissiontocoldersurfaces)
The(purelyphysical)processofheatexchangewiththesurroundingsisalsosubstantiallyinfluencedbytheschoolpupils’clothes.
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Underthethermalconditionsusuallyencounteredinsocialareas90%oftheheatisexchangedbyconvectionandradiation.Onlyatelevatedambienttemperatures(at27oCandabove)orduringvigorousactivities(P.E.lessons,playingontheplayground)isasignificantproportionofheatlostthroughevaporation.Convectionandradiationareinvolvedinheatexchangetoalmostthesameextent.Forthisreasonthetemperaturefeltbyhumanbeings(=operativetemperature)canbecalculatedasanarith-meticalmeanvalueofthetemperatureofthesurroundingareas(radiatedtemperature)andairtemperaturewithreasonableaccuracy.
Thetypicalsituationsinschoolswhichcanbelinkedtothermalloadin-cludeaboveall:
Warmconditionsatthestartoflessonsduetoincreasedheatlossafterbreaktimeactivity.
Uncomfortablywarmconditions,e.g.nearwindowfrontagesduetoincreasedabsorptionofradiatedheat(solarradiation,radiator).
Uncomfortablywarmconditionsatlessonstartduetointenseheatfromsolarradiationandnoactivesunprotectioninindoorareasfacingeast.
Uncomfortablywarmconditionsatlessonstartduetooverheating,solarradiationintheafternooninindoorareasfacingwest(evennorth-west)andduetoinactiveornon-existentsunprotectionandnocoolingduringthenightorearlymornings.
Riseinoperationaltemperatureduringheatwavesinsummer.
Riseinoperationaltemperatureandrelativehumidityduringlessonsduetoheatandwatervapourlossfromtheoccupantsinsituationswithinadequateventilation.
Uncomfortablycoldconditions,e.g.nearwindowfrontagesduetoincreasedthermalradiation(coldoutsidewall)orincreasedconvection(draughts).
Uncomfortablycoldconditionsinthemorningsduetolatestartofheatingfollowingovernightdropintemperature(heatingsystemonnightsetback).
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C-2.2 Technical requirements
Structuralandtechnicalprerequisitestoensureperfectindoorairqualityandagoodbuildingclimateinschoolbuildingsalsoincludeafavourablesituationandsizeoftheschoolsiteintermsofurbanplanningandmicro-climate.Theseincludeareasonableamountofsunshine,hardlyanyeffectsfromthewindorturbulence,nolargeemissionsourcesintheimmediatevicinityoftheschoolandaquietlocationawayfromtraffic.Alsonecessaryaregoodbuildinggroundandagoodarchitecturalsolutionforthebuild-ingitselfwhichtakesappropriateaccountoftherequiredsize,locationandfixturesandfittingsoftheteachingroomsandallotherfunctionalrooms.
Forseveralreasonsprotectingtheclassroomsfromheatloadinsummerasaresultofsunlightoverheatingindoorareasandhighexternaltempera-turesisbecomingincreasinglyimportant,thatis:
Inclassroomsarelativelylargenumberofpeople(particularlywithlargerclasses)occupyafairlysmallspaceduringlessons.Theresultisaheatlossthathastheeffectofinternalheatload.
Comparedtothepast,inmodernschoolstheceilingsinindoorareasarenowlowerthantheyusedtobeforcostreasons.Highceilingsarenolongercommon.Thisreducesairvolumeandthepossibilityofphysiologicalheatlossthroughconvection.
Fordesignreasons,largerwindowareashavebecomeestablishedinmodernschoolbuildingarchitecture.However,insummerthesecangiverisetounwelcomesolarradiation.
People’s thermal comfort is influenced above all by air temperature, ambienttemperatureandairmovement.
Physically comfortable operative temperatures (for classrooms accordingtoseasonandasafunctionofexternalair temperaturebetweenapprox.20–26oC)shouldbemaintainedthroughouttheyearasfaraspossible.
Walls,floorsandceilingsmustbedesignedinsuchawaythatnounpleas-antthermalradiationexchangewithcoldsurfacesoccurs.
Draughtsshouldbeprevented.
Individualclothingshouldbesuitablefortheseasonalandspatialcondi-tionsandmovement(academiclessonssittingdown,P.E.lessonsetc.).
What are the physiological requirements of human beings which must be considered in teaching rooms?
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Thinpartitionwallsand(forsoundpurposes)suspendedceilingswithalmostnocapacitytoabsorbheathavebecomecommoninteriorfix-tureswiththeresultthatinsummeranunwelcomeamountofheatisgeneratedinindoorareas.
Inaddition,thereisthefactthatthepossibleeffectsofclimatechangewhichareonlystartingtobefeltnow,willposeafargreaterproblemforfuturegenerationsofschoolpupilscomparedtotoday.Conservingheatinthewinterwillperhapsnolongerbethemainproblem,butpreventingindoorareasoverheatinginsummer.
Thegreatnumberofcausesmakespeopleassumethattherearealsomanyinfluencingfactorswhichmakeitpossibletocountersolarradiationinsummereffectively.Someofthesefactorsaredescribedinmoredetailinthefollowingsections.
Buildingorientationtogetherwiththeorientationofthemainbuildingfaçadescontainingwindowsarecrucial.North-southfaçadesperformfavourably,east-westfaçadesunfavourably.Contrarytopopularopinion,southfaçadesarenotgreatlyirradiatedbysunlightinsummerbecausethesuninthesouthatitszenithisperpendiculartotheearthatmiddayandthereforeonlyshinesonthefaçadeatanangle.Ontheotherhand,westfaçadesareaffectedbyalmostdirectsolarradiationwhenthesunislowerintheafternoon,causingconsiderableproblemsinwest-facingindoorar-eas.Moreover,duringsummerafternoons(fourtofiveo’clock)theexternalairtemperaturesarealsoattheirhighest,meaningthatalmostnoneoftheheatindoorscanbe“extractedoutside”insummer;ventilatingtheindoorareasatthistimebringsmoreheatintotheclassrooms.Thesameappliestoeastfaçadesduringthemorning.Mostindoorareasfacingeastwardshavealreadybeenwarmedupbeforethestartoflessonsorareheatedupatthestart.Incontrasttowest-facingindoorareas,thosewhichareeast-facingcanbewellventilatedinthemorningsbecausetheexternalmorningairisstillrelativelycoolinsummer.North-facingindoorareasreceivetheleastamountofsolarradiationandonlydiffusealmostneverdirectradiation.However,diffuseradiationgivesnorth-facingindoorareasexcellent,natu-rallightwithnoglareandforthisreasonartstudiostendtofacenorth.Rooflightsreceiveveryhighamountsofsolarradiationinsummer.How-ever,north-facingwindowsarerarelyusedinenergysavingconstructionmethodsbecausepeoplewanttomakeuseofthesunasapassiveenergysourcetowarmindoorareasinthewinter,autumnandspringmonths.
Thesize of the transparent window area playsacrucialroleinheatinginsum-mer.Façadeswithglazingproportionsexceeding40-50%arenottoberec-ommended.Togetherwiththethennecessarysun-protectiondevices,theycostseveraltimestheamountofnon-transparentwallsmadeoftraditionalbuildingmaterials.
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Dependingontheorientation,largeareasofglassrequiresun-protection devices.Asun-protectiondevicemustbeexternalinordertobeeffectiveinenergyterms.Deviceslocatedindoorshavenoenergy-relatedeffectasarule;atbest,theycanshieldagainstglarebutoffernothermalprotec-tion.Sun-protectiondevicescanberigidormoveable.Generallyarigiddevice,e.g.intheformofacanopy,isonlyinthecorrectposition(ifatallnecessary)ifsouth-facingbecausethecanopypreventsverticalradiationtherefromthesunatitszenith.Atthesametime,however,fixedsun-protectiondevicesreducetheamountofdaylightcomingintoareasfurtherbackinside.Eastandwest-facingwindowsneedmoveabledevices.Nosunprotectionisneededfornorthfaçades(butitisfornorth-eastandnorth-westorientationsinsummertopreventindoorareasheatingupintheearlymorningsandlateafternoons).Moveabledevicescanbecontrolledautomaticallyormanually.Theyshouldbeautomaticallycontrollableforeastfaçadesbecausethesensorstherehavetorespondasearlyasshortlyaftersunrise(atapprox.fiveo’clock).Solarcontrolglassisnottoberecom-mendedinschoolbuildings;glasswithhighlighttransmission,moderate,non-heat-gain-optimisedgvalue(totalenergytransmissionlevel)oftheglazingandexternallylocatedsunprotectionispreferable.Thesun-protec-tioneffectisindicatedbythe“totalsolarenergytransmittance”;itmustbeverifiedforthesun-protectiondevicetogetherwiththeglazingbyatestcertificatefromanaccreditedtestinginstitution.
Glass atria or foyers with glass roofsrequiretheinvolvementofbuildingphysicsexpertstobeproperlydesignedandconstructed.Insummerhorizontalglassroofsreceivethestrongestradiationofallbuildingcomponents.Thiscanbeasmuchas1,000W/m2atmiddayinextremecases.Sun-shadingintheformofexteriorawningsorsimilarareindispensablehere.However,theawningsmustnotobstructtheroofopeningsforventilationorsmokeextraction.Externalsun-protectiondevicesmustbeprotectedagainstdam-agefromsnoworfreezingwaterinwinter.Thesameappliestophoto-voltaicelementsinstalledintheroof.Onthereversesidethephotovoltaicelementsemitrelativelystrongheatflowstowardstheinside.Thisisoftenunderestimated;thesehavetheunwelcomeeffectofadditionalpowerfulradiatingceilingheatersinthesummeriftheyarenotputupatadistanceandback-ventilatedwithairfromoutside.
Heat-retaining componentsinbuildinginteriors(solidwallsandceilings)absorbindoorheatinsummer.Theindoorcomponentsareimportant;theretain-ingeffectoftheremainingsectionsofexternalwalls(nearthelargeareasofglass)isnegligible.Itispossibletopreventsolarradiationcominginfromoutsideinsummerbyhavingindoorcomponentsoftherightdimen-sions.Iftheyareintendedtoservetoretainheat,thesurfacesofsolidindoorcomponentsshouldnotbecoveredwithheat-insulatingcoatings
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becauseotherwisetheradiatedenergycannotbeabsorbed.Carpetsorhangingrugsreducetheretainingcapacityofaconcreteslabforexample.Usingwhatareknownasphasechangematerials(PCMs)canhelptopre-ventclassroomsoverheatingduringtheday.Dependingonthesettransi-tionpoint(e.g.25oC),thesematerialswhichresemblewaxaremelted,andtheheatwhichisabsorbedwithoutthetemperatureofthematerialsrisingfurthercanbe“discharged”duringthenightthroughventilation.
Theheatretainedintheindoorcomponentsduringthedayhastoberemovedfromtheinterioragainthroughincreasednight ventilation.Ifthisdoesnottakeplace,theindoortemperaturekeeps“swinging”higherdaybydayinsummer.Fortunately,inourclimatetheexternalairtemperatureatnightisusuallyloweveninsummer(thisisoftennotthecaseininnercitylocations)anditispossibletocoolindoorareasbyventilatingthematnight.However,largeopeningswhicharedesignedtobesecureagainsttheweatherandintrudersorcanbemonitoredbythecaretakermustbeinplacetoensureschoolindoorareasareairedatnight.Alternatively,ven-tilatingindoorareasearlyinthemorningsinsummerwhenhighoutdoortemperaturesareexpectedcancertainlybeeffectiveandpossiblyeasiertoorganise.
Evidently,protectingschoolindoorareasfromoverheatinginsummercanbeachievedthrougharaftofmeasures;notallofthesemustbeadoptedatonceinindividualcases,rather,theyshouldbeselectedsinglyorincombi-nationasappropriate.AmongothersDIN4108(Part2)givesguidanceonthis(duetothehighinternalloadresultingfromthelargenumberofpeopleinclassroomsitisnotexpectedthatthemaximumtemperaturesgiveninDIN4108(Part2),includingtheshortexceedancetime,willbeadheredto).
Permissibleindoorairtemperaturesinschoolsandofficesinsummercauseregu-lardiscussionsbetweenbuildingoperatorsandthoseaffected.However,accord-ingtotheWorkplaceOrdinancethere isarecommendation (notamandatoryregulation)thattheindoorairtemperatureintheworkplaceshouldnotexceed26oC.Yetthegeneralbuildingphysicsprinciplethatinourlatitudesitmaybehotterforshortperiodsduringthedayinsummerapplies.Itispossibletoadheretothisbuildingphysicsprincipleinalmosteverycaseiftheinfluencingfactorsreferredtointhissection(C-2.2)areconsistentlyborninmindthroughoutthedesignphase.Strictlymaintainingtherecommended26oCwouldrequiretheuseofair-conditioningsystemsinschools.
How high can the indoor air temperature in indoor areas in schools be in summer?
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C-2.3 Ventilation technology
Free ventilation:
Thisiswindowventilation,alsocalled“free”or“natural”ventilationwherebynoventilationsystemsorotherventilationequipmentisused.
Inschoolsthepreferenceforusingfreeventilationoftenrepresentsacom-promisebetweencostandsuccess.Classroomscannotbeventilatedbywin-dowsthroughouttheyearinsuchawaythatthedesiredlimitsofthermalcomfortandairqualitycanbemaintainedatalltimes(cf.SectionC-2.1).Particularlyinwinteritcanhappenthatthosesittingnearthewindowscomplainoffeelingcoldwhenthewindowsareopenedforalongtimetoventilatetheroom.Ontheotherhand,adheringtothehygienerequire-mentsintermsofcarbondioxidemustbeensuredifpossibleduringandattheendoflessons(cf.SectionB-1).Forthisreasonitisessentialthat,eveninthewinter,classroomsareconsistentlyventilatedduringbreaktimes,aswellasduringlonglessonsoriftheclassesareveryfull.
Rooflightsandpivot-hungwindowsshouldstayopenatnightduringperi-odsofwarmweather(providedtheyaresecuredagainstbreak-in),sothattheindoorareascancooloffmoreeffectively.Howcanthewayinwhichusersventilateschoolshelptoimproveairquality?
Mechanical ventilation:
Mechanicalventilation(ventilationsystem)offerstheadvantageofmain-tainingacertainminimumnumberofchangesofairindependentofthebuildingusers.Moreover,mechanicalventilationhastheaddedenergy-relatedadvantagethatitcanbeconnectedtoaheatrecoverysystem.Theaircirculatedtotheindoorareasshouldconsistof100%freshairwithoutanyadded“recirculatedair”(“recirculatedair”referstoairextractedfromonearea,whichhasbeenfilteredandthenrecirculatedbacktotheindoorareas).Correctdesignandconstructionandoperationandmaintenancerequireapplicationoftherelevantstandardsandguidelines,inparticularDINEN13779andVDI6022.
Ventilatingregularly,ideallyusingcrossventilation.
Ventilatingregularly,ideallyusingcrossventilation.
Avoidingallowingindoorareastogettoohotortoocold.
How can the way in which users ventilate schools help to improve air quality?
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Mechanicalventilationcanhelptowardscoolingthebuildingwithinten-siveventilationatnightduringthesummermonths(cf.notesonnightventilationinSectionC-2.2).
C-2.4 Acoustic requirements
Eveninthebestschoolsteacherscannotteachiftheintelligibilityoftheirspeechsuffersonaccountofpooracousticsinthebuilding.Notonlyisitimportanttopreventtheeffectsofnoisefromoutside.Equallyimportantarethedesignandconstructionrequirementsinandonbuildingstoim-provetheacousticsinside.
Theacousticdesignofschoolsandteachingroomsaimstocreateopti-mumconditionsforpromotingratherthancompromisingthehealthandachievementofpupils.Thisappliestotheuseandusabilityofteachingrooms,dependingontherelevantenvironment(schoolbuildings,sur-roundingarea),butindependentofpedagogicplanningandtheindividualrequirementsofthechildren.Afurther,fundamentalaspectofthesustain-ableacousticdesignofteachingroomsisseeingacousticsasanintegral,indispensablepartofbuildingdesign.
Area of application:
Acousticdesignaffectstheacousticpropertiesoftheentireschoolbuilding,includingthebuildingitselfandtheindoorareas,thatis:
generalteachingrooms,
specialistteachingrooms(music,sportetc.),
socialareas,including
corridorsandstairways.
Onlybyconsideringtheseholistically(seeFigure1),isitpossibletoachieveoptimumworkingandlearningconditions.Thebuildingacousticsproper-tiesincludethesoundinsulationofwalls(externalandinternal),ceilings,roofs,doorsandwindowsagainstnoise(e.g.trafficnoiseoutsideandvoic-es,musicetc.inside),offloorsagainstimpactsound(e.g.peoplewalking,includingchairmovementetc.)andagainstnoisefrombuildingservicesequipmentandinstallations.
Thepropertiesoftheacousticsinindoorareasincludemutualspeechintel-ligibilityandthewaytheareahelpstoamplifyormufflethesounds,inparticularofspeech.
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Thelawsofphysicsresultinvaryingdegreesofinteractionbetweenstruc-turalandacousticpropertiesinbuildings.Thustheresultingsoundinsula-tionbetweenadjacentareasdependsonboththesoundreductionofthewallcomponentsandthesoundproofingintheroomsthemselves.
Acoustic parameters and values: A) Sound insulation
BuildingacousticsvaluesandtheirrespectivelimitvaluesaresetouttogetherinTables9-11.
Table 9: Required minimum sound reduction (weighted sound reduction index Rw) of components between indoor areas in school buildings according to DIN 4109
Component part between teaching rooms and..Min. sound reduction index Rw [dB]
Walls Teachingrooms 47
WallsSpecialistteachingrooms(music,sport,workshopsetc.)
55
Walls Corridors 47
Walls Stairways 52
Doors Corridors 32
Table 10: Maximum impact sound pressure level (weighted normalised impact sound pressure level Ln w) in indoor areas in school buildings, according to DIN 4109
Component partbetween teaching rooms and..
Max. normalised impact sound pressure level L’n,w [dB]
Walls Teachingrooms 46
WallsSpecialistteachingrooms(music,sport,workshopsetc.)
46
Ceilings under corridors 53
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Table 11: Maximum noise level (characteristic sound pressure level LA f) in teaching rooms caused by building services systems, installations and various systems in school buildings with reference to DIN 4109
The effect of noise in ... Max. Sound pressure level (sum level) LA, f [dB(A)]
Teaching rooms 30
Specialist teaching rooms (music, sport, workshops etc.)
35
ThevaluesinTable11onlyapplyduringtheday,i.e.duringschoolhours.Itisessentialthatstrangenoises,e.g.isolatedorrecurringvolumepeaksorvolumefluctuationsandisolated,pronouncedsoundsbeavoided.
Withreferencetosoundinsulationagainstoutsidenoise,therequirementsofDIN4109applytotheexternalcomponentsofschoolbuildings.Inpar-ticular,noisesresultingfromtrafficorothersources,whichhaverecurringvolumepeaksorvolumefluctuationsandisolated,pronouncedsoundsmustbetakenintoaccount.
B) Indoor acoustics
Traditionally,thebestknownparameterfordescribingtheacousticproper-tiesofindoorareasisreverberationtime.Thevalueswhichmustbead-heredtoaregivenaccordingtoareaandapplytotheareaswhenunoccu-pied.TheyaresummarisedinTable12.Thevaluesapplytotheusualaudiofrequencyrange,i.e.totheoctavebandsfrom63Hztoapprox.8KHz(mid-frequencies).
Table 12: Obligatory reverberation time values, including tolerance, in indoor areas in school buildings
Area type Reverberation time T in s
Teaching rooms (with a volume below 300 m3)
recommended0.5±0.05s
Teaching rooms, sports halls, gyms and swimming pools (dependent on volume)
accordingtoDIN18041“Audibilityinsmalltomediumsizedrooms”
Ahighlevelofspeechintelligibilityisimportantinschools.Therever-
berationtimesgiveninTable12thereforedifferslightlyfromthoseinDIN18041.Noise-absorbentceilingsshouldnotbeusedalonetoreducereverberationtime.Therearwallareabeneaththeceilingisalsosuitable.
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Ahighlevelofspeechintelligibilityisimportantinschools.Thereverbera-tiontimesgiveninTable12thereforedifferslightlyfromthoseinDIN18041.Noise-absorbentceilingsshouldnotbeusedalonetoreducerever-berationtime.Therearwallareabeneaththeceilingisalsosuitable.
Inlargersportshallsandareasusedforsimilaractivities,acorrectlydeter-minedreverberationtimewhichtakesaccountoftheoftenvariedusesofthehallshouldbemaintainedinanyevent.Itisrecommendedthatspecialconsiderationandtreatmentbegiventotheindooracousticsinspecialisteventandmusicareas,e.g.schoolhalls.
RecommendationsforadditionalindoorareasinschoolbuildingscanbefoundinTable13.Theydonottargetgoodspeechintelligibilitysomuchasattenuationofveryloudnoiseswhichoccurtherefromtimetotime.
Tabelle 13: Recommended reverberation time values, including tolerance, in indoor areas of school buildings (cf. Figures 2 and 3)
Raumart Nachhallzeit T in s
Corridors, stairways T=V/1000m3+0.8
IntheequationtheVisthevolumeforconnectingareas,e.g.thosesepa-ratedbydoors,inm3.Thecalculatedvaluesshouldbeconsultedforareasmeasuringapprox.100m3to800m3.ReferencevaluesforsmallorlargervolumesareshowninFigure2.
Besidesthereverberationtime,theambientnoiselevelalsodeterminestheacousticpropertiesinindoorareas.Theambientnoisesproducedoutsidetherelevantareaatleastareaddressedthroughthepropertiesinpara-graph“A”(soundinsulation).
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General advice on practical acoustic design:
Instandards,guidelines/directivesandotherliterature,thereisawealthandvarietyofbuildingdesignoptionsforallaspectsofsoundinsulation(e.g.DIN4109)andforconfiguringindooracousticconditions(e.g.DIN18041).Inmanycases,especiallyfornewbuildingsorlargerrefurbishmentsorextensions,anacousticsexpertshouldbeconsultedifpossible.
Acousticqualityasdescribedinthisguideisimportantforbothexistingandnewschoolbuildings.Withproperplanningalltheparametersreferredtocaneasilybeimplemented,usingcommerciallyavailablecomponents.This isalsotrueinthe context of the remaining structural andbuildingphysics requirements forschoolbuildings.
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Reve
rber
atio
n ti
me
Volume m3
Figure2:Indooracoustic(1–reverberationtime)andbuildingacoustic(2–soundinsulationofwallsetc.,
3–impactsoundinsulationofceilingsandfloors,4–soundinsulationofexternalbuildingcomponents
5–noisefrombuildingservicesinstallations)influencesonthequalityofschoolbuildings
Figure3:Recommendedreverberation-timevaluesasafunctionofthevolumeforcorridorsandstairways
inschoolbuildings.
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PART D: Procedures in problem cases
D-1 Basic procedures
Inthissectionexamplesofproblemcases(casestudies)arepresented.Aware-nessofproblemsinsideschools,nurseryschoolsanddaynurserieswillgener-allyberelatedtothecause,inmostcasesbecauseofsymptomsofillnessoraparticularoccurrence.However,specificenquiriesbecauseofmediareportsorroutinechecksandprecautionaryinvestigationscanalsobethecatalyst.
Inmostcasespublichealthserviceinstitutions,i.e.thehealthandenviron-mentagencies,theindustrialhealthserviceortheappropriateaccidentinsurersareinvolvedastheprimarycontactsoftheinstitutions’control-lingauthorities.Inthesecasesastructuredprocedureshouldbeexpected,generallyresultinginarationalandefficientsolutiontotheproblem,which,inthecontextofriskcommunication,shouldleadtoacceptancebythoseaf-fected.
Thesituationoftenbecomesmoredifficultifaneedforseriousactionisestablishedfrominappropriatemeasurementsandexaggeratedevaluations,andextensiveunnecessaryfollow-upinvestigationsandrecommendationsforremediationensue.
Thefollowingcasestudiesaresetoutasastructuredprocedureanddealwiththecause(e.g.healthproblems),asummaryofthesituation(Siteinspec-tion,questionsasked,buildingconstruction,files),furtheractionthroughinvestigations(readings,enquiries),evaluationoftheresults,theconsequentrecommendedactionandmeasures,andtheoutcomeachieved(continueduse,acceptance).
Thefollowingactionplan,whichclarifiestheindividualstages,canbeseenasasuggestedprocedureinproblemcases.Itdoeshoweverdependonbring-inginexpertcompetencefromthehealthauthoritiesatanearlystageandinvolvingthoseresponsible(schoolauthority,buildingauthority,industrialhealth,accidentinsurers,etc.)andthoseaffected(e.g.parents,users)equallythroughtransparencyoftheprocess;moreover,allparticipantsshouldun-derstandandacceptthestepschosenanddecisionstaken.Thisalsoincludestakingthecomplaintsandhealthproblemsseriously,makinginformationavailableatalltimes,involvingthoseaffectedinthedecision-makingprocess,andcommittingoutsideagents(measuringinstitutes,renovationcompanies,tradesmen,etc.)toqualityassurance(e.g.minimummeasuringrequire-ments),aswellascarryingoutafinalcheckandinspection(assessmentofsuccess),ifpossiblewithallparticipants.
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Diagram4:Flowchart:proceduresincasesofillness,seedoublepagefollowing.
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Influ
ence
Phas
es o
f bui
ldin
g w
ork
Proc
edur
eRe
spon
sibi
litie
s
PT
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P
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of
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stru
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nLa
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eria
ls s
ched
ule/
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ope
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/use
of s
pace
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uctu
re a
nd c
ause
s, re
pairs
Acou
stic
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Ener
gy
cons
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Leak
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mal
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dges
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ser
vice
sy
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sEn
ergy
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ance
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mpe
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res-
cons
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tion
Heat
ing
times
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/ w
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ing
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s
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use
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allo
catio
nRe
arra
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ent
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erva
tion
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ithFu
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ergy
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imum
of
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dow
ap
ertu
res
Man
ual,
hybr
id
vent
ilatio
nHe
at p
rote
ctio
nDa
y lig
ht
ilum
inat
ion
…Air
qual
ityNe
eded
air
ex
chan
geRe
duci
ng
sunl
ight
in
fluen
ce
Ther
mic
bui
ldin
g st
ruct
ure
Air
tight
ness
Heat
ing
cons
truc
tion
Hydr
aulic
sy
stem
Cont
rolle
rHe
atin
g sy
stem
Man
agem
ent
utili
ties
Room
div
isio
nAc
ustic
s…
Parents/pupils
Teacher/other staff
Building contractor
Authorities
Planning office
Obse
rvat
ion
of c
omfo
rt c
ondi
tions
Exam
inat
ion
of c
ost-
effe
ctiv
enes
s
Cons
truc
tion
time
plan
Usag
e pe
riod
of s
choo
lTr
ansf
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ce o
f tea
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g es
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ishm
ent
Sim
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ntem
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ion
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ergy
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serv
atio
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dina
nce
…
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D-2 Case studies
D-2.1 Mineral fibres from suspended ceiling construction
Cause/authority contacted:Healthagencynotifiedbyschoolauthoritybecauseofteachers’healthproblems.
Situation:Teacherscomplainingofeyeandthroatirritationsanditchyskin.
Site inspection:Suspendedconstructionslattedceilinginthestaffroom.Fornoisecontrol,mineralwoolmatshavebeenlaidontheslatswithoutafilterlayer.Theventilationsystemblowsincomingairdirectlyintothesuspendedceilingabovetheleveloftheslatsandinsulationmats.Thereareconsider-abledustdepositsonthecupboards.
Investigations:Anexaminationoffibres(inaccordancewithVDI3492)revealedacombinationofmineralfibreswithaKIof<30andaclassifica-tioninthecategoryK2.Indoorairmeasurementsproducedarespirableinorganicfibre(WHOfibre)contentof7000/m3.
Evaluation:Theconstructionisevaluatedasinadequateandunacceptable(nofilterlayer,incomingairblowingthroughit).Theemissionoffibresissignificantlyraised(tomorethan1000fibresperm3),sincethetechnicalconstructiondoesnotmeetwithup-to-datetechnicalstandards.
Recommendations:Removethemats,observinghealthandsafetyatworkcon-ditions,andreplacewithaproblem-freematerialwithafilterlayer.Altertheairsupplyintotheroombyputtinginventsattheleveloftheslatsorbyturningofftheventilationsystem.Washsurfacesintheroomsregularly.Usevacuumcleanerswithparticulatematterfilters(HEPAfilters).
Action and outcome:Riskcommunicationwithschoolmanagementteamandstaff,explanationofthetoxicologicalevaluationofsyntheticmineralfibres.Clearreadingaftercompletionofremediation(<500F/m3).Noproblemssince.
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D-2.2 Chloronaphthalene in prefabricated school buildings
Cause/contact with authorities:Requestfromtheschoolauthority(localauthor-ity)tothehealthagencyowingtounpleasantodours,presumablybecauseofamouldattackfollowingflooddamageinaschoolcomplex.
Situation:Thisconcernsa1970sschoolcomplexofprefabricatedconstruc-tion.Waterdamageoccurredintheroomsasaresultofleakingflatroofs.Unpleasantodourshadbeenevidentforsometime,whichwereattributedtotheflooding.Mouldreadingshadalreadybeentakenbythelocalhy-gieneinstitute,showingaraisedgermcountintheindoorair.Noexplana-tionfortheunpleasantodours.Schoolchildrencomplainedofstingingeyes,burningskin,sorethroatsandheadaches.Theparentsreportedasmell“clinging”tothechildren’sclothes(“staleschool”).
Investigations:AnalysesoftheindoorairproducedanunremarkablesampleoftheusualVOCs,butwiththeunusualadditionofchloronaphthalenes(CNs)atlevelsupto50μg/m3.Furtherreadingsrevealedasignificantdependenceontemperatureandaconcentrationrangeof1–5μg/m3fornaphthaleneandbetween2and50μg/m3formono-anddichloronaphtha-lene.A“musty”odourwasrecordedbythepeopletakingsamples.Exami-nationofthematerialsamplesidentifiedthesourceoftheCNsastypeV100Gwaterproofparticleboard.FurtherenquiriestothemanufacturerrevealedtheuseofthewoodpreservativeBasileumSP-70,whichcontainschloronaphthalene,onthereversesideoftheboards.
Evaluation:Theevaluationwascarriedoutusingaprovisionallyderivedguidelinevalue(interventionvalue)of200μg/m3andanenvironmentalhygienetargetvalueof20μg/m3becauseoftheunpleasantodourandthecredibleeffectsobservedonhealth.
Recommendations:Fromanindoorhygienepointofview,becauseofthewa-terdamageanddetectionofthelocalisedmouldattack,andbecauseoftheamountsofchloronaphthalene,acomprehensiveremediation(removaloftheV100Gboards,roofrenovation)orrebuildingwasrecommended.
Action:Localcouncil,staffandparentswereinformedofthefactsinpublicbriefingmeetingsheldjointlybythehealthagencyandthespecialistagen-cies.
Outcome:Thelocalauthoritydecidedtodemolishtheschool,becauseofitsage(intendedfor20years’usewhenerected)andthehighcostofrenova-tion,anderectedanewbuildinginsolidconstruction.
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D-2.3 Odour pollution in classrooms after the long holidays
Reason/contact with authorities:Healthagencycontactedbytheschoolauthor-ityonaccountofanunusual“chemicalsmell”ineightclassroomsataprimaryandsecondaryschool.
Situation:Thisconcernsroomsintheoldpartofaprimaryandsecondaryschool,whichaccordingtotheseniormanagementis100yearsoldandhasneverbeenaffectedbyhealthproblemsorbadodoursuntilnow.Twoyearsagotheoldbox-typewindowswerereplacedwithmodernplasticwindows.Atthebeginningofthesummerholidaysthecleaningstaffpolishedthewoodblockfloor–asusual–withaliquidwax.Fromthesafetydatasheetitcanbeseenthattheproductcontainsnaphtha(petroleum,lowaromaticcontent).
Site inspection:Oldbuildinginverygoodstateofrepair,withold,wellmain-tainedwoodblockfloor.Strongodourof“floorpolish”.
Investigations:Indoorairreadingsusingactivesample-taking(NIOSHtubes)overfourhours,afterdoorsandwindowswerekeptclosedovernight.Result:veryhighsolventconcentrationsinalleightroomswithTVOCcon-tentsbetween10and23mg/m3.TheguidelinevalueRWIIwasexceededforthealkaneandaromaticgroupofsubstancesandfornaphthalene.Theprofileoftheindoorairmatchedthecompositionofthefloorwax,towhichtheintensiveodourofalkylaromaticswastracedback.Asconstitu-entsofthesolventthesehavealowerodourthresholdthanthealkanes.
Evaluation:AccordingtotherecommendationsoftheIRK/AOLGadhocwork-inggroup(cf.SectionB-2)thepollutionshouldbeclassifiedas“category5”:TVOCvaluesbetween>10and25mg/m3areclassifiedashygienicallyunac-ceptable.Usingtheroomshouldgenerallybeavoided,althoughspendingashorttimeiniteachday(lessthan1hourperday)isreasonableifmoreintensiveregularventilationmeasuresarecarriedout.Atvalues>25mg/m3theroomshouldnotbeusedatall.ValuesexceedingRWIIdemandanimmediateinspection,e.g.regardingmeasuresanddecisionstoreduceexposure.Thefollow-upreadingtochecktheindoorairqualitytakesplaceundernormaluse.
Theuseofthefloorpolishatthebeginningoftheholidayswasestablishedasthecauseoftheunpleasantodour.Thiscontinuedtohaveaneffectoverafairlylongperiod,astherewasnoactiveventilationintheholidaysafterthepolishingtookplace.Asaresultofinstallingtightlyclosingwindowsthenaturalairexchangewasnolongersufficienttoremovethesolventodourfromtheairinside,asithadbeeninpreviousyears.
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Recommendations:Sincetherewasnoalternative,itwasrecommendedthattheroomsbeusedonconditionthatparticularlyintensiveventilationmeas-ureswereimplementeduntiltheoutcomeofthecontrolreadings.
Action and outcome:Follow-upreadingswereimmediatelyarrangedundernormalconditionsofuse.TheresultsshowedTVOCconcentrationsbetween0.06and0.4mg/m3.Thenaphthalenecontaminationoftheindoorairwasbetween3and10μg/m3andthusintherangebetweenRWIandRWII.ThecomparativeTVOCreadingsunderstandardisedconditions(withoutairingbeforehandandwindowsclosedovernight)showedasignificantdrop(previously23,now1.5mg/m3).
Theresultsweresetoutinariskcommunicationtoseniormanagementandstaff,parents’representatives,educationauthorityandplanningdepart-mentandcontinueduseassessedastolerablewithstrictadherencetoven-tilationmeasures.Follow-upinspectionsinfourweekswerearranged,anditwasrecommendedthatinfutureafloorwaxwithoutaromaticcontentshouldbeused,ensuringadequateairingafterthefloorispolished.Themanufacturerwascontactedwiththerecommendationtoincludeadviceonincreasedventilationafteruseintheinstructionsandtocheckthecombina-tionofsolventsusedintheformulation,since,contrarytotheinformationgiven,aproductcontainingaromaticshadpresumablybeenused.
Twomonthsaftertheincidentthemanufacturerrepliedthatadifferentsol-venthadbeenusedintheformulationfromtheonehehadspecified.Thefaultybatchwastakenoffthemarket.
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D-2.4 Persistent indoor air pollution resulting from the use of solvent-based cleaner on woodblock floors
Cause/contact with authorities: Telephonecallfromtheheadteacher10weeksafterthoroughcleaningonaccountofaturpentine-likeodour.
Site inspection:Two-storeyextension(builtin2000)ataprimaryandsecond-aryschool,containingfourclassrooms,agrouproomandacomputerroom.Floorconsistingofunsealedwoodenboards(robust,canbesandedrepeat-edly).
Facts:Thoroughcleaningduring2003summerholidayswithC4,asolventfor–accordingtothemanufacturer–“effortlessremovalofoldlayersofwax,oil,fatandgrease”,thenhardglosswax.Sametreatmentinallroomsexceptcomputerroom,especiallystrongodourinoneclassroomonthegroundfloor.
Investigations:InitialmeasurementofVOCcontentintheclassroom,takingthrougharound600litresofair.Samplealready“overloaded”,noanalysispossible.Thefollow-upVOCreadingshowedbetween7and40mg/m3forthetotalVOCs.AnalysisofthecleanerC4showedacorrespondingspectrumofVOCs.Comparativereadingsintheoldbuildingproducednothingunu-sual.Inthefollowingyearsrepeatedreadingsinallaffectedroomsundercontrolledconditionsandinnormaluse(upto17readingsinoneclass-room).
Useoftheroomswassubjecttoastrictventilationregime,whichwasfol-lowedrelativelywell.
Outcome:Theprofileoftheanalysesremainedsimilarthroughoutandonlyfellveryslowly(alkanes,terpenes).Undernormalconditionsofusethevalueswerealwayssignificantlylower.Overthewholeinvestigationperiodtherewerenocomplaintsaboutadverseeffectsonhealth.Theclassroomwhichwasinitiallymostcontaminatedalsoretainedanoticeablesolventsmellforthelongesttime.ThelastreadingsinFebruary2006wereintheorderoflessthan1mg/m3.
Action:Despitetheclaim“Foruseonsolvent-proofflooring,e.g.unsealedwoodfloors”itisrecommendedthatthisproductshouldnotbeusedonwoodfloors,especiallywheretherearecracksandeasilyaccessiblecutsurfaces.Correspondingadvicetothemanufacturertochangetheclaimac-cordinglyhasreceivednoresponsetodate.
Recommendation:Totheschool:Continuewiththoroughairing.Useaspecial-istflooroilanalysedinalaboratorybeforehand,appliedsparinglytothesurface.Tothecleaningstaffinthebuilding:C4cleanershouldnolongerbeusedintheareaconcerned.
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D-2.5 Indoor air contamination with dibasic dimethyl esters (DBE)
Cause/contact with authorities: Healthofficeinformedbytheschoolauthorityafterabnormalindooraircontaminationestablishedbyacontractedlabo-ratory.Whendoingthis,thelaboratoryreferredtotherecommendationexpressedbytheIRK/AOLGadhocworkinggroupintheinstructionsforevaluatingindoorairpollutantstocallintheappropriateregionalauthor-ityincasesofraisedvalues.Thereadingsweretakenbecauseofcomplaintsofhealthproblemsamongchildrenandteachers.
Site inspection:Primaryschoolingoodstateofrepairwithcarpetedfloorsintheclassrooms.Unpleasant“sweet”smellinasectionofthebuildingrenovatedsixmonthsearlier.Therewerenoindicationsofthisintheotherpartsofthebuildingthathadbeenupgradedpreviously.
Facts:Inthesecondhalfof2007thispartofthebuildingwasrenovatedfol-lowingthesamepatternasothersectionstheyearbeforeandnewcarpet-ingwaslaid.Intheinvitationfortendersthearchitectexpresslyspecifiedtheuseofenvironmentallyfriendlyproducts.Aftertherenovationtherewereimmediatecomplaintsaboutbadodoursandadverseeffectsonhealth(irritationoftherespiratorytracts).Atfirsttheodourwasconsideredtoberelatedtotherenovation,andowingtothechoiceofmaterialsandtheinformationonthesafetydatasheetsitwasassessedasharmlesstohealth.Afterthecomplaintshadpersistedforsixmonthsanenvironmentallabora-torywasfinallycommissionedtotakeindoorairreadings.
Results of the investigations:Intheroomsconcerned,exceptforsignificantlyraisedconcentrationsofdibasicdimethylesters(sum∙ 1500μg/m3),anoth-erwisenormalVOCprofile(otherVOCsapprox.300–400μg/m3)wasfound.
Outcome:Theprofileoftheanalyseswassimilar(C4-C6dibasicdimethylestersbetween600–1600μg/m3)intheroomsthatwererenovatedsixmonthsearlier.Innormalusewithintensiveventilationthevalueswerelower(under100μg/m3).
Action:Inaprovisionalevaluationtheregionalauthorityresponsiblede-rivedaprovisionalguidelinevalue(interventionvalueof500μg/m3andatargetvalueof50μg/m3forthesumoftheC4-C6dibasicdimethylesters(CAS95481-62-2).Becauseoftheexcessvaluesandtheadverseeffectsonhealthreportedallsuspectedroomswereimmediatelytakenoutofuse.Furtherreadingswerearrangedtoclarifytheextentofthecontaminationandtoestablishthesource/cause,includingbycoresamplesandtestsonmaterials.Theparentsreceivedaletterinformingthemofthesituationandaquestionnairewasdistributedtofindoutaboutadversehealtheffectsamongchildrenintheroomsconcernedandinuncontaminatedrooms(controlgroup).Withinaweek230outof350questionnaireswerereturned
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andanalysed.Theseshowedahigherprevalenceofnasalirritations,sorethroatsandhoarseness,coughsandshortageofbreath,andheadachesamongthechildreninthecontaminatedroomscomparedwiththecontrolrooms.Theincreasedandunusualdisordersamongthechildrenwhohadbeenexposedcouldplausiblybeattributedtothetoxicityofthedibasicesters.Theresultsoftheinvestigationsandthesurveywereexplainedatapublicmeetingattheschool,whereparentsreportedanimmediateim-provementinthesymptoms.Asecondsurveyfollowedthreeweekslater.Bythistime,havingvacatedtherooms,thechildren’sdisordershadsubsidedandwereatthesamelevelasthecontrolgroup.
Recommendation:Roomsnottobeuseduntilthecauseofthecontaminationwasidentifiedandeliminated.AsthiswasthefirsttimethatDBEshadbeenshowntocontaminateindoorair,acorrespondingreportwassubmittedtotheFederalInstituteforRiskAssessmentinaccordancewithArticle16ChemG.Thecasewassubsequentlyexaminedfurtherwiththeparticipationoftheconstructioncompanyandthemanufacturerofthebuildingmateri-alsused.TheywereabletopinpointthecauseastheuseofapolyurethanelevellingcompoundwithahighDBEcontentinthefloorconstruction.Aftertheseexperiencestheuseofdibasicestersinindoorenvironmentsmustberegardedascritical.
Theexampleshowsthatincasesofunusualindoorcontaminationwith“new”substancesandoftheexistenceofadverseeffectsonhealththeap-propriateprofessionalinstitutionsshouldbeinformedimmediately,andthat–despitetheinstructiontouseenvironmentallyfriendlyproducts–abnormalindoorairpollution,inthiscaseevendetrimentaltohealth,canoccurtimeandagain.
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D 2.6 Health problems in a new wing of a primary school
Cause: Twoyearsafterbuildinganewschoolwingwithatotalof4class-roomsand2multipurposeroomsobvioussymptomsfirstappearedinpu-pilsandstaffattheendofSeptember/beginningofOctober.Parentsreport-edthat10childrenweresufferingfromseveretoveryseveresymptomsandthat9outof10ofthechildrenweregoodtoverygoodpupils.Thefollow-ingcomplaintswerereported:severeheadaches(6children),stomachacheandnausea(7children),peribronchitis(1child),skinrashesorunexplainedallergies(2children),redandstingingeyes(3children).Theskinreactionsextendedtothelegsandoccasionallyalsotothefaceandneck.Someofthechildrenhadalargenumberofabsences.Onechildwasexaminedbydoc-torsforatumourbecauseofextremeheadaches–withnegativeresults.Itwasnoticeablethatthesymptomsfirstarosewhentheheatingwasonandthat4ofthe10childrensatdirectlynexttotheheaters.Itwasalsostrikingthatsymptomssuchasreddeningoftheeyeshadalwaysbeguninschoolandsubsidedintheafternoon.Thechildrenwereallreceivingmedicaltreatment,andnocausecouldbeidentified.Thedoctorsruledoutorganiccauses.Theteacherscomplainedofheadachesandsorethroats.
Action:Afterthefirstcomplaintshadbeenlodgedwiththetowncouncilanindustrialhealthinstitutionwascommissionedtocarryoutairmeasure-ments(passivecollectors).Nothingunusualwasfound.However,in6airreadingsaltogetheronlytoluene,xylenesandethylbenzeneswereana-lysed.Basedonthevaluesmeasuredthedirectorofthedistricthealthofficegavetheall-clear.
Course of events:Thehealthproblemscontinuedtoincreaseduringthefollowingthreeyears.Inparticular,moreandmorechildreninthe“newclassrooms”inthiswingweresufferingsymptoms.Eventuallytheparentsof16childrenrefusedtoallowtheirchildrentohaveanyfurtherlessonsinthenewbuilding.Atthattimefiveteachersinallwerekeepingawrittenrecordoftheappearanceofthesymptoms,especiallyheadaches,butalsodifficultiesinswallowing,throatirritations,andreddeningoftheskin.Theclassesweremovedtootherroomsintheoldbuilding;teachers’andpupils’symptomsdisappearedcompletely.
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Investigations:31/2yearsafterthefirstindoorairreadingsweretakenfurtherinvestigationswerecommissioned.Firstly,afteraninspectionofthepropertyinquestion,aVOCairmeasurementwithactivatedcarbonandsilicagelcollectorsandaMVOCairmeasurementwithactivatedcarbontubeswerecarriedout(activesampling).Theseproducedindicationsofmicrobialdamage(evidenceofthemainindicators1-octen-3-ol,3-methyl-furananddimethyldisulphide).TheVOCairmeasurementproducedaverylowtotalTVOCconcentrationof230μg/m3,althoughat24.2μg/m3therewasanabnormalconcentrationof2-ethyl-1-hexanol,whichwastracedtothehydrolyticdisintegrationofthesoftenercompoundDEHP.Themeasure-mentwithsilicagelcollectiontubesrevealed109μg/m3of2.6-di-t-butylcresol.
Inallsevenmaterialsamplesofinsulationmaterial(polystyrene)andthedividinglayers(foilandpaperboard)weretakenoutofthefloorsandana-lysed.Infiveofthesevensamplesamassivemicrobialinfestationwasde-tected:thiswasparticularlysevereintheinsulatingmaterial,with850,000CFU/gofmould(aspergillusversicolor,penicilliumspp.,acremoniumsp.)and14,000,000CFU/gofbacteria(actinomycetesandbacillusspp.).Emis-sionsanalysesoftheflooringmaterials(PVCwithadhesiveandfiller)re-vealedabnormalemissionsof2-ethyl-1-hexanol.Whenthefloorwasopenedupitwasdiscoveredthattherewerehighlevelsofdampinthefloorundertheinsulationlayerandthattherewasanobvioustostrongmustyodourfromthefloor.
Thecauseofthehighmoisturelevelswasestablishedafterlengthyinves-tigations.Inthiscasetheywerenotcausedbystructuralfailings,butbythecleaningstaff,who,inthecourseofwashingthePVCfloorseachweekalwaystippedlargequantitiesofwaterontothemandlikedtosweepittothesideswith“squeegees”.Thewaterranintothegapsattheedges.
Recommendation:Thefloorswererenovatedonaccountofthefindings.Afterthatthesymptomssubsided.TheMVOCconcentrationsintheindoorairweremonitoredover12monthsinall,andonlyreachedbackgroundlevelsafteraboutayear.Asthesymptomshaddisappearedcompletelyaftertheremediation,despiteMVOCconcentrationsthatwerestillraisedatthestart,thisisaclearindicationthattheMVOCsdidnotdirectlycausethesymp-toms,butweresimplyanindicatorofthemicrobialdamage.
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PART E: Remediation guidelines and procedures
Inresponsetothecontaminationofbuildingswithhazardoussubstanceswhichbecameapparentsincethe1980s,the“pollutants”projectgroupoftheBauministerkonferenz[buildingministers’committee](Arbeitgemein-schaftderfürStädtebau,Bau-undWohnungswesenzuständigenMinisterder16Länder[ConferenceoftheLänderMinistersandSenatorsresponsibleforurbandevelopment,constructionandhousing]–ARGEBAU)devisedasetofguidelines.ThesewereintroducedascompulsorytechnicalbuildingregulationsinthemajorityoftheLänderandshouldthereforegenerallybeobservedduringremediationwork–inschoolsaselsewhere.Inaddi-tionARGEBAUpublishedthePAK-Hinweise[AdviceonPAHs](June2000),throughtheGermanInstituteforConstructionEngineering(DIBt),whichcanbeconsultedasnon-bindingrecommendationsforrenovatingwood-blockfloorslaidwithtar-basedadhesives.Theguidelinesandrecommenda-tionsreferredtoaresetoutinbriefbelow.
E-1 Asbestos
InMay1989the“RichtlinienfürdieBewertungundSanierungschwachge-bundenerAsbestprodukteinGebäuden”(Asbest-Richtlinien)[Guidelinesfortheevaluationandremediationoflooselyboundasbestosproductsinbuild-ings(AsbestosGuidelines)]werepublishedbytheARGEBAUprojectgroup.ArevisededitionwasissuedinJanuary1996andsubsequentlyintroducedastechnicalbuildingregulationsbytheconstructionauthorityinallLänder.
Theseguidelinesincludevariousevaluationfigures,accordingtothetypeofasbestosproduct,thestructuralcondition,theavailabilityoftheprod-uct,andthenatureandfrequencyoftheuseofthespacebythegroupofpeopleconcerned.Thesumoftheevaluationfiguresthenshowswhetherremediationisrequiredimmediately,inthemediumtermorinthelongterm.Insomecasesanindoorairmeasurementmayalsobenecessary.Oncompletionofremediationwork,tomonitoritssuccess,readingsoftheconcentrationofasbestosfibresintheindoorairshouldbecarriedoutinaccordancewiththeasbestosguidelines.Aftersuccessfulremediationtheasbestosconcentrationshouldbebelow500fibres/m3ofair.
Formostoftherelevantschoolbuildings,whichwereconstructedinthe1960sand1970s,thisevaluationmaybecompletedinthemeantimeusingtheasbestosguidelinesandappropriateremediationmeasurescarriedout.
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Theprinciplesofasbestosremediationaresummarisedinthefollowing(inanextractquotedfromtheasbestosguidelines):
1. “Remediationmeasuresmustbeplannedasaclosedconceptfromthebeginningoftheworktothedisposalofthewasteinaccordancewiththeapplicableregulations.
2. Onlythosefirmsshouldbecommissionedwhoarefamiliarwiththework,thehazardsarisingfromitandthenecessaryprotectivemeas-uresandwhohaveaccesstothenecessarytoolsandequipment.
3. Protectivemeasuresarenecessaryatalltimesduringtheremediation.”
Theplanningdepartmentsareresponsiblefortheremediationworks,andappointcompetentfirmsinaccordancewithPoint2.Iftheremediationhasnotyetbeencarriedout,itisessentialtoensurethatfibresarenotreleasedintotheindoorairthroughservicing,cleaningormaintenancework.
E-2 Polychlorinated biphenyls
AftertheproblemofcontaminationofbuildingswithPCBs–mainlyemittedbysealantscontainingPCBs,whichweremanufacturedanduseduntilthemid-1970s–cametolight(cf.SectionB-4),the“RichtliniefürdieBewertungundSanierungPCB-belasteterBaustoffeundBauteileinGebäu-den(PCB-Richtlinie)”[GuidelinesfortheevaluationandremediationofPCBcontaminatedmaterialsandcomponentsinbuildings(PCBguidelines)]weredevisedbythepollutantsprojectgroup.Theseguidelinescontainahealthevaluation,listremediationprocedures,evaluatetheirurgencyandgiveadviceontheup-to-datehealthandsafetyatworkregulationsaswellasanoverviewofrelevantlawsandordinancesrelatingtothedisposalofPCBcontaminatedproducts.InadditionrecommendationsfordeterminingthePCBsintheindoorairanalyticallyareprovided.TheguidelineswerepublishedinthereportsoftheGermanInstituteforConstructionEngineer-ing(DIBtNo.2,1995,pp.50–59).TheyhavebeenintroducedastechnicalbuildingregulationsbytheconstructionauthorityinmostLänder,evenifwithconsiderablealterationsinsomecases,andassuchshouldberegardedasbindinginconstructionlaw.
Itisaprerequisiteforproperremediationthatthemeasuresareplannedasaclosedconceptfromthebeginningoftheworktothedisposalofthewaste,andthatonlythosefirmsarecommissionedwhoarefamiliarwiththerelevantproblemsandpotentialhazardsandwhohaveaccesstothenecessarytoolsandequipment.Theremediationworkmustbecarriedoutwithaslittledustaspossible.Thefirststageofapermanentremediation
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isgenerallytheremovaloftheprimarysources.InsomecasesseparatingofftheareaofthebuildingcontaminatedwithPCBsfromunpollutedareaswithsolidstructures(dividingwalls,etc.)canalsobeasensibletemporarymeasure.Iftheindoorairconcentrationcannotbeloweredtothetargetvaluesspecifiedintheguidelinesimmediatelywiththesemeasures,there-mediationofsecondarysourcesisnecessaryaswell.Thesecondarysources,oftencoveringlargeareas(e.g.wallsandceilings),canberesurfaced,sepa-ratedofforevenremoved.
AfterremediationthePCBconcentrationintheindoorairshouldnotexceed0.3μg/m3ofairinthemiddleoftheyearifpossible.AsthePCBconcentrationinindoorairissubjecttoseasonalvariationsintemperature,asinglereadingisnotnecessarilyrepresentativeofthemid-yearvalue.VDIGuidelines4300part2containsinformationonasuitablemeasuringstrat-egyfordeterminingPCBsinindoorair.
E-3 Pentachlorophenol
In1996theARGEBAUpollutantsprojectgroupdevisedguidelinesfortheevaluationandremediationofPCP-contaminatedbuildingmaterialsandcomponentsinbuildings(thePCPGuidelines).TheGuidelineswerepub-lishedintheGermanInstituteforConstructionEngineeringreports(DIBtNo.2,1997,pp.6–15).ThePCPguidelineswerealsointroducedbythecon-structionauthoritiesinmostLänder.
Theflowchartshownintheguidelinesfordeterminingtheneedforreme-diationenvisagesthatitwillfirstbeestablishedwhetherwoodpreservativeshavebeenusedinconstructionmaterialsandcomponentsinthebuildinginquestion,orwhetherotherPCPsourcesshouldpossiblybesought.Ifwoodpreservativeshavebeenused,stagedtestswillbeneededonthedust,thetreatedwoodandtheindoorair,inaccordancewiththeaforemen-tionedflowchart.Theremediationdecisionshouldbededucedfromtheseonthebasisofthelimitvaluesstipulated.Possibleremediationmeasurescouldbe–ifviablefromaconstructionperspective–boththeremovalofthetreatedmaterialsandmeasuressuchasresurfacingandliningorseparatingofftheareawithtreatedcomponents.Theapplicablelegalre-quirementsforthedisposalofmaterialscontainingPCPsaresetoutintheguidelines.
Forprecautionaryhealthreasonsanindoorairvalueof<0.1μgPCP/m3ofindoorairshouldbethelong-termgoaltoaimatwhencarryingoutreme-diationwork.Thesuccessoftherenovationshouldbeverifiedbydetermin-
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ingthePCPcontentoftheindooraironthebasisoftheVDIGuidelines4300part4and4301part2.
InwoodpreservativesPCPwasusuallypresentwiththeinsecticidelindaneintheproportion10partsPCPto1partlindane(cf.SectionB-4).Accord-ingtotheevaluationoftheformerFederalInstituteforHealthProtectionofConsumersandVeterinaryMedicine(BgVV)adversehealtheffectscanveryprobablyberuledoutifanindoorairvalueof1μglindane/m3ofairismaintained.Indoorairvaluesof1μglindane/m3ofairandaboveareonlyreachedafterusingwoodpreservativesifthePCPpollutionisalsosignificantlyabove1μg/m3.ThePCPrelatedremediationthenrequiredalsoreducesthelindaneconcentrationfarenough.
E-4 Polycyclic aromatic hydrocarbons
In2000theARGEBAUpollutantsprojectgroupdevisedthe“HinweisefürdieBewertungundMaßnahmenzurVerminderungderPAK-Belastungdu-rchParkettbödenmitTeerklebstoffeninGebäuden(PAKHinweise)”[AdviceonevaluationandmeasurestoreducePAHcontaminationbywoodblockflooringwithtar-basedadhesivesinbuildings(PAHAdvice)].Thiswaspub-lishedinDIBtreportNo.4(2000)pp.114–123.
Thetar-basedadhesivesthatwereusedtogluewoodblockflooring,mainlyinthe1950sbutoccasionallyrightuptothe1970s,camebrieflytopublicattentioninthe1990s,afterraisedPAHconcentrationswerediscovered,forthemostpartinbuildingsformerlyoccupiedbyUSforcesinGermany.Theseweretracedbacktoadhesivesunderdilapidatedwoodblockfloors.Asthesemi-volatilePAHsaremainlytakenupbydust,theprojectgroupreachedthefollowingevaluation:“InthecaseofPAHcontaminationbytar-basedwoodflooradhesivesnoriskthresholdcanbeset,atwhichmeasuresareurgentlyneededtomeetplanninglegislation,overandaboveprecau-tionarymeasures.However,theadhocworkinggroupconsiderstheoccur-renceofcertainBaPconcentrationsundesirableonhygienegrounds…”
Benzo(a)pyrene(BaP)isregardedhereastheleadsubstanceforthegroupofpolycyclicaromatichydrocarbons.
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Theprojectgroupassumedthatingeneralrepairingthedamagedwoodfloorbyfillingthedefectivejointsandthensealingitissufficientandcom-pleteremovaloftheflooringandstrippingofforsealingoffthetar-basedadhesivesisonlynecessaryinseverecases.Theprojectgroupcametothefollowingconclusionforevaluatingthesuccessoftheremediation:
1. Inroomsusedforlongperiodsmeasurestoreduceexposureshouldbeintroducedifhousedustconcentrationsexceed100mgBaP/kgoffreshdust.
2. Inhomesorotherspaceswherebabiesorsmallchildrenregularlyspendseveralhoursadayoverafairlylongperiodandwhereexpo-suretodustistobeexpectedfromthetypeofuse,e.g.indaynurseriesorchildren’shomes,measurestoreduceexposureshouldbecarriedoutifhousedustconcentrationsexceed10mgBaP/kgoffreshdust.
Insomejustifiedcasesadditionalmedicalexaminationswererecommend-ed.ThePAHAdvicealsocontainsrecommendationsforhealthandsafetyatworkandfordisposalofwastecontainingPAHs.
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Appendix 1:
(Specimen) school hygiene plan
InaccordancewithArticle36para.1oftheProtectionagainstInfectionsAct(IfSG)schoolshaveadutytosetoutinternalproceduresforthemain-tenanceofinfectionhygieneinhygieneplans,inordertominimiseriskofinfection.Theplansshouldbedrawnupinthefollowingstages:
Analysisoftherisksofinfection
Evaluationoftherisks
Riskminimisation
Establishmentofmonitoringprocedures
Reviewofthehygieneplan
Documentationandtraining.
Thefollowingspecimenhygieneplanprovidessuggestionsfordevisingahygieneplanappropriatetothespecificcircumstancesoftheschoolcon-cerned.
Cleaning plan
Thecleaningplanshouldbeappropriatetothespecificcircumstances(hardwashablefloororcarpeting)oftheschoolconcernedinaccordancewiththeguidelinesinDIN77400“CleaningServices–SchoolBuildings–Clean-ingRequirements”forboththeschoolbuildingsandtheattachedsportsfacilities(seealsoA-2CleaningProcedures).
Thefollowingareasshouldbetakenintoaccount:
theentrancearea
thegroundfloortrafficareasandthestairstothefirstfloor
theremainingcorridorsandstaircases
classrooms
sanitaryareas,includingchangingrooms
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staffrooms,schooloffices,administrativeareas,officesandmeetingsrooms
storerooms
gymnasia
schoolmealskitchens,homeeconomicsroomsanddininghalls
Thoroughcleaningandmaintenanceshouldbecarriedoutinallareasoftheschoolatleastonceayear.Forroutinecleaningandtheannualinten-sivecleaningormaintenanceonlycleaningproductswhichposenohealthriskshouldbeused.Ifseveralcleaningproductsareused,acheckshouldbeundertakentomakesurethattheproductsdonotreactwithoneanotherandthatmixingthemdoesnotproducesubstanceshazardoustohealth.
“Cosycorners”inschoolsshouldbeavoidedifpossible.If,however,thesedoexist,itmustbeensuredthattheyarecleanedthoroughlytoanappro-priatestandardeveryweek.
Ventilation plan
Iftheschoolhasnomechanicalventilation,theclassroomsshouldbeaired,wherepossiblewithcross-ventilation,atleastaftereverylesson(45min-utes)andatthebeginningandendoftheschooldayduringterm-time.Theseniorstaffdecideswhoairstheclassroomaftereverylessonandhowitistobeaired.Inthelowerschooltheteacherwhoispresentshouldberesponsibleforthis.Intheupperschoolapupilrotacanbedrawnupforthisfunction.
AshumanshavenosensoryorganfordetectingtheCO2contentoftheair,
ventilation“trafficlights”canbeameansofvisualisingtheindoorairqual-ity.“Ventilationbehaviourtraining”canbecarriedoutinthisway.
Besidesregularmaintenance,existingindoorair-conditioningsystemsmustbeinspectedinaccordancewiththetechnicalregulations(VDI6022–Hy-gienerequirementsforair-conditioningsystemsandappliances).Aspecialinspectionisneededforthesystemcomponentswhichcontainmoistureintheformofwaterorcondensingwater,suchashumidifiersorheatex-changers.
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Noise reduction plan
Inschoolsthenoisefromthevicinity(road,railandairtraffic,industrialactivities),frompoorroomacousticsorfromthepupilsthemselvescanpresentaparticularproblem.TheWorkplacesOrdinanceprescribesanaveragemeasurementof55dB(A)forworkplaceswithpredominantlyintel-lectualactivity.
1. Noise from the surrounding area
Possiblemeasurestoreducetheeffectoftrafficnoisefrombusyroads:
Ventilationburstsinsteadofcontinuousventilationtoreducetheentryofnoisefromoutside
Installationofsoundproofwindows
2. Room acoustics
Speechintelligibilityisinfluencedmainlybythereverberationtime.Theacousticpropertiesofaroomareestablishedandevaluatedobjectivelybymeasuringthisreverberationtime.Thereverberationtimeinaclassroomshouldbeintheregionof0.5seconds.Byinstallingnoise-absorbentmateri-alinaroomthereverberationtimeisreducedandtheacousticsoptimised.
Simplemeasuresforimprovingroomacoustics:
Mufflingcontactofmoveablefurniturewiththefloor
Fittingfeltpadstochairandtablelegs
Oilingsqueakingdrawers
Installingnoise-absorbentfurnishings
Puttingupcurtainsatthewindows
Puttingupwallhangingsorcorktiles(e.g.pinboards)
Installingpanellingonwallsfromfloorleveluptoabout1.5metres(agreementfromeducationdepartmentorpublicworksdepartmentrequired)
Checkingceilingpanelsandinstallingnoise-absorbentceilingandwallpanelsifnecessary(agreementfromeducationdepartmentorpublicworksdepartmentrequired)
Usingquieterappliances(e.g.computerstationswithquietfans)
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Whenconstructingnewschoolbuildings,undertakingremediationorreno-vationorsubmittingcomplaintsthenewApril2004editionofDIN18041“Acousticqualityinsmalltomedium-sizedrooms”shouldbereferredto.
3. Organisational and educational recommendations
Puttinguprulesforhearingandlistening
Coveringthetopic„Noiseandtheeffectsofnoise”inclass(materialsforthisareavailablefreeofchargefromtheFederalCentreforHealthEducation(BZgA))
Usingvisualaidsfornoisereduction,e.g.Soundearor“noisetrafficlights”
Reducingclasssizes
Havingshortbreaksinthemiddleofdoublelessons
Conductingtraininginimprovedsocialbehaviour
Speakingslowlytoimprovespeechintelligibility
Ensuringeyecontactbetweenspeakerandlistener
Introducingsomephysicalexercisesifconcentrationflags
Voicetrainingforteacherstoprotectvocalcords
Stressmanagementprogrammesforteachers
Water hygiene
Inschoolsshowersinsportsfacilitiesandswimmingpoolscanposeapartic-ularproblemwithregardtolegionellacontamination.Topreventlegionel-lashowersthatarenotusedeverydayshouldberinsedthroughbyrunningthehotwaterdailyforaround5minutes(setthemaximumtemperaturetoatleast60oC).Limescaledepositsshouldberemovedfromtheshowerheadsattherequiredintervals.Thehealthagencyshouldbeconsultedaboutthenecessityforregularbacteriologicalinspectionsforlegionella.
Ifdrinking waterisusedinthepreparationoffoodordrinks,thewaterinthepipesshouldberunofffirst.
Thewaterinschool swimming pools shouldbetreatedinaccordancewiththeguidelinesinDIN19643.Itmustbeensuredthatthewaterinswimmingandbathingpoolsdoesnotposeanyhealthrisk.TheProtectionagainstInfectionsAct(Article37)providesthelegalbasisforthis:“Waterinswim-
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mingandbathingpoolsincommercialoperations,publicbathsandinothernotexclusivelyprivately-usedfacilitiesmustbesuchthatthereshouldbenoconcernthatanyharmtohumanhealth,especiallyfrompathogens,couldarisefromusingit”.
Inthisregardparticularattentionshouldbepaidtotheproperdisinfectionofthepoolwater.Thelimitvaluefortrihalogenmethanesof20μg/llaiddowninDIN19643mustbecompliedwith.Itmustbeensuredthatthestaffresponsibleforthepoolmachineryreceiveregularfurthertraininginthisfield.WithregardtothistherecommendationsoftheFederalEnviron-mentAgency/theBathingWaterCommission(seeBundesgesundheitsbl–Gesundheitsforsch–Gesundheitsschutz9,2006)andotherhygienerecom-mendationsshouldbetakenintoaccount.
Verruca infections in swimming pools and gymnasia /sportshalls
Besidesthegenerallywidespreadathlete’sfootinfectionstheoccurrenceofverrucasissometimesobservedinrelationtotheuseofswimmingpoolsandsportshalls.Verrucas/wartsandmolluscumcontagiosum(MC)areamongthemostcommonskincomplaintscausedbyviruses.Theycanoc-curatanyage,butwarts,especiallyMC,areparticularlycommonamongchildrenandadolescents.
Wartvirusesareusuallytransmittedbydirectorindirectcontact.Thiscanoccurthroughphysicalcontact,butalsothroughshareduseoftowels,sandalsetc.orthroughcontactwithflakesofskinonthefloor.Properlydisinfectedpoolwaterplaysnopartintransmission,asthepathogensarerenderedinactivebythechlorineinthewater.Itismorelikelythattransmissionarisesthroughdampseatingandfloorsroundthepoolandintheshowerandchangingroomcubicles,ifthesehavepreviouslybeenusedbyacarrierofverrucasorathlete’sfoot.Forthisreasonthesesurfacesaredisinfectedatleastonceadayatpublicbaths.
Measurestopreventtransmission(prophylaxis):
Teachers,especiallyP.E.andswimminginstructorsandpre-schoolstaffshouldbeinformedabouttransmissionroutes.
Parentsshouldalsobeinformedandshouldexplaintherelevantmeas-urestotheirchildren.Thesolesofchildren’sfeetandbetweentheirtoesshouldbeinspectedfrequently.
Beforeswimmingoneshouldwashthoroughlyfromheadtotoe,sothatthechlorineinthewaterdoesnotloseitsdisinfectanteffectbe-causeoforganicsubstances(sweat,oils).
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Sandalsshouldbeworninindoorpoolsandchangingrooms.
Shareduseoftowels,lotionsetc.byseveralpeopleshouldbeavoided.
Oneshouldnotwalkaboutbarefootincommunalfacilitieswithath-lete’sfootorverrucasthathavenotclearedup.
ThedoctoradministeringtreatmentshoulddecideonparticipationinswimmingorP.E.lessons,ifthisinvolvesphysicalcontact(possiblywithawrittencertificate).
Operatorsofswimmingpools,saunasandsportsfacilitiesshouldcarryoutorarrangeforthecleaningofpassageways,showersandchangingrooms,aswellasotherareasusedwithbarefeet,everyday,orwherenecessary,severaltimesdaily.
Attheendoftheworkingdayallsurfacesusedwithbarefeetinswim-mingpools,saunasandsportsfacilitiesshouldbecleanedusingadis-infectanttestedforitsvirucidalefficacy.Theproductshouldbeappliedwiththescrubandwipeprocedure.Sprayingaloneisnotsufficient,asskinflakesarenoteffectivelyremovedbythis.
Kitchens
Homeeconomicskitchensandschoolmealskitchensshouldbetreatedinthesamewaywithregardtothehygienerequirementstobemetinthem.PeoplesufferingfromaninfectionasdefinedbyArticle42oftheProtec-tionagainstInfectionsAct(IfSG)orfrominfectedcutsorskincomplaints,fromwhichthereisariskofpathogensbeingtransmittedviafood,maynotbeemployedinthekitchen.InaccordancewithArticle43oftheActthekitchenstaffshouldbeadvisedoftheworkingrestrictionsonceayear.
Thekitchenstaffshouldreceiveannualtraininginfoodhygiene.
Hand disinfectionbythoseworkinginkitchensisrequiredinthefollowingcases:
whenstartingwork
afterbreaks
aftereachvisittothelavatory
afterdirtyjobs
afterworkingwithcriticalrawgoods(e.g.rawmeat,poultry)
aftercoughingorsneezingintoone’shand,everytimeafterusingahandkerchief.
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Onlypreparationsthathavebeentestedandproveneffectivemaybeused.InthecaseofhanddisinfectantproductstheseshouldbechosenfromthedisinfectantslistissuedbytheDeutscheGesellschaftfürHygieneundMikro-biologie[Germanassociationforhygieneandmicrobiology].
Walldispensersshouldbeprovidedatwashbasinsforwashinganddisin-fectinghandsinthekitchenarea.Thecontentsofsoapanddisinfectantdis-pensersshouldbecheckedweekly.Beforerefillingthedispensersshouldbecleanedout.Liquidsoapsanddisinfectantsshouldbekeptintheiroriginalcontainers.
The procedure should be described:
Forexample:bothsidesofthehandstobecovered,togetherwithwrists,betweenthefingers,fingertips,cuticlesandthumbsandleftfor30secondsforthedisinfectanttowork.3to5mlofdisinfectant(acuppedhandfull)isneeded.
Thefloorsinthekitchenareashouldbecleaneddaily.Protectiveclothingshouldbeprovidedforparticulartasks(e.g.cleaningfloors).Thisprotectiveclothingshouldbechangeddaily,orasnecessary.
Surface disinfection is necessary:
whenworkingwithcriticalrawgoods(e.g.rawmeat,poultry)
afterfinishingworkonsurfaceswhereanimalproductshavebeenprepared.
Thedisinfectantisappliedtothesurfaceconcernedandspreadvigorouslywithaclothorsponge(scrubandwipedisinfection).Thedisinfectantmustbelefttotakeeffectbeforethesurfaceisusedagain.Surfacesthatcomeintocontactwithfoodshouldberinsedwithcleanwaterafterwards.
Topreventdeteriorationinfoodqualitythroughpestinfestationsfoodstuffsshouldbepackagedcorrectly(e.g.wrappeduporinbins)andthepackageslabelledwiththedateopened/dateprocessedandthecontents.
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Thefollowingin-housefoodinspectionsshouldbecarriedout:
goodsinspectiononarrivalforpackaging,bestbeforedates,varioustypesofdamagetogoods
dailytemperaturechecksonrefrigeratorsandfreezers(refrigerator<8oC,***freezer<-18oC)
weeklycheckonbestbeforedatesonfoods
inthecaseoffoodspreparedonsite,samplesshouldbestoredinfreez-ersfor96hours,separatedaccordingtoingredients.
Animal pests (parasites)
Inschoolsanimalpestscanbothattackhumansintheformofparasitessuchaslice,oroccuraspestsinclassrooms.
Outbreaksofheadliceinchildrenarearecurrentprobleminschools.Con-trollingoutbreaksofheadlicerequiresclosecooperationbetweenparents,schoolandhealthagency.Everycaseoflicemustbereportedbynameinwriting(byletter,faxore-mail)tothehealthagency,inaccordancewithArticle34oftheProtectionagainstInfectionsAct(IfSG).Apreciseplanofactionshouldbeputinplacefortheprocedureintheeventoftheoccur-renceoflice.
Example:
Ifachildisfoundtohaveheadlice,he/sheshould(afterconsulta-tionwiththeparents)besenthomeassoonaspossible,tocommencetreatment.ifthatisnotpossible,e.g.becausetheparentscannotbecontacted,thechildcanremaininthebuildinguntiltheendofhis/herusualsession.Closecontactduringthefollowinghoursshouldbeavoidedviadiscreetmeasures.
Withtheagreementoftherelevanthealthagencytheschoolinformsthepupils’parentsorguardiansoftheoutbreakoflice.Indoingsoanydiscriminationagainstthechildrenaffectedshouldbeavoided.
Theparentsareaskedtoexaminetheirchildrencarefully,andinthecaseofinfectiontocarryouttreatmentasdirectedbyadoctor.Atthesametimeexaminationandifnecessarytreatmentofallcontacts(families,friendsetc.)shouldtakeplace.
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IftreatmentoftheheadliceinfectionisundertakenimmediatelyandaccordingtotheencloseddirectionsusingaproductrecommendedbytheRobertKochInstitute(doctor’sprescriptionadvisable,alsoregardinginsuranceclaims),theaffectedchildrencan,dependingontheinfection,return to school straight away on the day after the initial treatment,iftheparentsconfirmthecorrectimplementationofthismeasurebywrittenreplyoradoctorcanruleoutthefurtherspreadofheadlicewithahighdegreeofcertainty.Thereplyshouldreachtheformteacherpromptly,withinthreedaysatthelatest.Itisessentialthattheparentsshouldbemadeawarethatasecond treatment is neces-sary within 8-10 days.
Ifnoreplyisreceivedwithinthisperiod,theestablishmentshouldwherepossibleattempttocontacttheparentsofthechildrenaffected(e.g.bytelephone).Ifnecessarytheyshouldbeaskedtoattendanotherexamination.Ifindividualparentsarenotwillingtocooperatedespitetheinformationreceived,alegalbasisforfurthersteps(meetingwithparents,examinationtoestablishfitnessforschool)isavailableintheeducationact.
TheProtectionagainstInfectionsActlaysdownthatthechildshouldbereadmittedtoschoolassoonas“intheopinionofadoctor”thereisnolongeranyriskofafurtherspreadoflice.TheActdoesnotdemandawrittencertificate.Inpracticeitcanbeassumedthatthedoctorinformsthepatientatthestartoftreatmentwhentherewillnolongerbeanyriskofcontagion.Adoctor’scertificateshouldbepresentedifthesamechildisre-infectedwithheadlicewithinfourweeks.
Inthecaseoffrequentoccurrencesofheadliceinoneschooladvicetoparentsandchecksonrepliesinparticularshouldbesteppedup.Thisappliesbothtorepliesfromtheaffectedchildrenandtorepliesfromchildrenwhohavehadcontact.Onlywhenalltheparentsofchildrenincontactsendrepliesorotherwiseconfirm,e.g.bytelephone,thattheirchildrenarefreeoflice,cantheschoolbesurethattheinforma-tionhasreachedallparentsandthatperhapspreviouslyunidentifiedcasesoflicearethereforebeingtreated.Theextentandtypeofadviceandtheproceduresshouldbelaiddowninconsultationwiththerel-evanthealthagency,which,dependingonthesituation,supportstheschoolincarryingoutthenecessarymeasures.
Kitchenareasareparticularlyatriskfromanimalpestinfestations.Kitchensshouldthereforebeinspectedregularlyforpest infestations.Intheeventofaninfestationpestcontrolmeasuresusingthemostup-to-datemethods
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shouldbecarriedoutbyaspecialistcompany.Particularcareshouldbetakensothatfooddoesnotcomeintocontactwithpestcontrolprepara-tionswhilethisistakingplace.
Foodwastemustbestoredinsealablecontainers,whichshouldbecleanedouteachtimetheyareemptied.Wastestoresmustbeabletobekeptcleanandfreeofanimalpests.Kitchenwindowsthatcanbeopenedtotheout-sideshouldbefittedwithinsectmesh.
Infectious diseases
Ahygieneriskfrombacteriaandvirusescanarisethroughtransmissionofinfectiousgermsfromonepersontoanotherviadropletorcontacttransmission.Thetransmissionofdiseasessuchasinfluenza,scarletfever(streptococcus pyogenes)andwhoopingcough(bordetella pertussis)ishowevernotaproblemspecifictoschools.TopreventthemtheencloseddirectionsfromtheRobertKochInstitute(e.g.HinweisefürÄrzte,LeitungenvonGemeinschaftseinrichtungenundGesundheitsämternzurWiederlassunginSchulenundsonstigenGemeinschaftseinrichtungen[Advicefordoctors,managementofcommunityfacilitiesandhealthagenciesonreadmittancetoschoolsandothercommunityfacilities],updatedversionofJuly2006,firstpublishedinBundesgesundheitsblatt44(2001):pp.830-843)shouldbeobservedandthechildreninstructedinhandhygieneandcoughetiquette.
First aid
Minorcutsshouldbecleanedwithtapwater(drinkingquality)beforedressing.
Thefirstaidershouldweardisposableglovesanddisinfecthis/herhandsbeforeandafteradministeringaid.Thenatureoftheinjuryshouldbeenteredintheaccidentbookinthefirstaidcabinet.Theparentsshouldbeinformedofthecause,natureandseverityoftheinjury.
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Informationshouldbeprovidednearthefirstaidcabinetonwhothefirstaiderinthisareaisandwhichdoctortocall(providetelephonenumber)formoreseriousaccidents.Thisnoticeboardshouldalsodisplayinstruc-tionsonhowtodealwithcasesofpoisoning(provideemergencynumberforpoisons)andfires.
Checking first aid contents
Suitablefirstaidmaterialsinaccordancewiththepreventionofaccidentsregulation“GUVErsteHilfe0.3”arecontainedin:
largefirstaidchestequippedinaccordancewithDIN13169
smallfirstaidchestequippedinaccordancewithDIN13157.
Thefirstaidcabinetshouldadditionallybeequippedwithanalcohol-basedhanddisinfectantinasecurelysealedcontainer.Usedmaterials(e.g.dispos-ableglovesandplasters)shouldbereplacedpromptly,andregularchecksshouldbeundertakenonthecontentsofthefirstaidchests.Inparticular,theexpirydateonthehanddisinfectantshouldbechecked.
Treatment of contaminated surfaces
Surfacescontaminatedwithblood,vomitorotherpotentiallyinfectiousbodilyfluidsshouldbescrubbedwithadisinfectant-soakedclothandtheaffectedsurfacedisinfectedagainafterwards.Disposableglovesshouldbewornthroughout.
Procedures in the event of hygiene problems
If“classic”hygieneproblemsariseinaschoolorindoorcontaminationwithharmfulsubstancesissuspectedorestablished,thefirstactionistoinformtheschoolauthorities.Theywillinformtherelevanthealthagencyandtherelevantoccupationalhealthdepartment.Theseinstitutionswilltogetherputinplacethenecessarycrisismanagementmeasures.Thiscrisismanage-mentincludesinformingteachers,pupilsandparents.Ifitisnecessarytoundertakeenvironmentalhealthinspectionsorbuildingsurveysorcallinfurtherprofessionals,theseshouldbeorganisedbytheschoolauthoritiesafterconsultationwiththerelevanthealthagencyandtherelevantoccupa-tionalhealthdepartment.Theschoolauthoritiesareresponsibleforcheck-ingthenecessarycompetenceofthetradesmenbroughtin.Theteachingstaff,pupilsandparentsshouldbeinformedoftheresultsoftheseinvestiga-tions.
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Symbols1.1.1-trichloroethane. 432-ethylhexanol. 42,.45α-pinene. 41β-pinene. 41δ-3-carene. 41
AAcetophenone. 43Acrolein. 43Acrylic.fabric. 44Actinomycetes. 69Acoustics. 93,.95Acoustic.ceiling.boards. 65Acoustic.ceiling.constructions. 67Acoustic.parameters. 94Acoustic.requirements. 93Acoustic.quality. 97Added.disinfectants. 23Adhesives. 83Ad.hoc.working.group. 13,.38,.46,.62Adipates. 55AgBB..(Ausschuss.zur.gesundheitlichen..Bewertung.von.Bauprodukten.–..Committee.for.the.Health.Evaluation.of.Building.Products). 75AgBB.evaluation.scheme. 30,.75Agents.in.wood.preservatives. 54Airborne.pollution.in.the..surrounding.area. 17Air.change.number. 24,.36Air-conditioning.scheme. 11Alcohols. 42,.81Aldehydes. 23,.42Aliphates. 40Alkenes. 40,.41Alkyd.resin.varnishes. 81Allergens. 68,.70
AOLG. 13Animal.allergens. 68Aromatics. 104,.105Aromatic.compounds. 41Asbestos. 63,.64Asbestosis. 65Asbestos.guidelines. 65Asbestos.product. 64Asbestos.spray. 64
BBacteria. 69Benzaldehyde. 42Benzene. 41Benzo(a)pyrene.(BaP). 59,.114Biological.substances. 68Biopersistence. 64,.67Biosoluble.SMF..insulation.materials. 67Blue.Angel. 81Blue.Angel.ecolabel. 29Bricks. 77Bromine. 26Brominated.compounds. 54Bronchial.tubes. 60Building.climate. 86Building.products. 30,.75,.76,.83Building.products.containing. 64Building.shell. 76Butanone. 43Butanonoxim. 40,.45Butyl.acetate. 43
CCarbon.dioxide.(CO
2). 25,.35
Carbon.monoxide.(CO). 35,.38Carcinogenicity.Index.(KI-Index). 66Carpeting. 21Case.studies. 99,.102
Appendix 2: Index
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Changing.rooms. 22Chemical.wood.preservatives. 58Chemistry.laboratories. 32Cleaning.intervals. 19Cleaning.procedures. 19,.20Cleaning.products. 23Chloranisols. 43Chlorine.gas. 26Chloronaphthalene.in..prefabricated.school.buildings. 103Chloronaphthalene. 59,.103Classrooms. 17,.21Cloakrooms. 18Clophen.A50. 56Clophen.A60. 56CMR.substances. 33CO
2.concentrations. 36,.37
CO2.content.of.outside.air. 35
CO2.problem. 37
Coal.stoves. 59Coarser.particulate.matter. 60Complaints,.authorities..responsible.for. 29,.99Combustion.processes. 62Composite.wood.panels. 78Comprehensive.hygiene.plan. 23Concrete. 77Construction.Products.Act..(Bauproduktengesetz). 75Convection. 86Copiers. 34Corridors. 20Cosy.corners. 21Critical.fibres. 63Cross-ventilation. 25Cyclohexanone. 43
DDay.lighting. 24Demountables. 8Di-2(ethylhexyl)phthalate.(DEHP). .55Dibasic.dimethyl.esters. 107
Dichlofluanid. 58Diisobutyl.phthalate.(DiBP). 55Diisocyanates. 53Dimethylformamide. 44DIN.77400. 19Dining.rooms. 22Disinfection.by-products.(DBPs). 26Disinfectant.cleaning. 20Di-n-butyl-phthalate.(DBP). 55Di-iso-nonylphthalate.(DINP). 55Dust. 60
EEC.Construction.Products.Directive.75ELF.paints. 82EMICODE. 80Emulsion.paints. 82EN.13779. 37Energy.Conservation.Ordinance..(Energieeinsparverordnung,.EnEV).7,.11Esters. 43Ethanol. 42Ethyl.acetate. 43Evaluation.for.carbon.dioxide. 35Evaluations.of.VOC.concentrations. 45Evaporation. 86Extraction.systems. 24Extractor.hood. 33,.34
FFibre.dusts. 63Fine.particles. 34Fire.retardants. 34,.54First.aid.contents. 127Fixtures.and.fittings.for..indoor.areas. 84Floor.coverings. 84Floor.covering.adhesives. 82,.83Food.distribution.points. 22Formaldehyde.(CH
2O). 42,.52,.53
Formaldehyde.emissions. 53Formaldehyde-free. 78,.85
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Free.ventilation. 92
Fundamental.hygiene.requirements.17
Fume.cupboards. 32
Furfural. 42
Furnishings. 18
GGas.cookers. 38
General.hygiene.requirements. 17
Glass.roofs. 90
Glasswool. 63,.65
Glutardialdehyde. 23
Glycols. 42
Glycol.ether. 42,.81
Glyoxal. 23
Guideline.value.I.(RW.I). 13,.46
Guideline.value.II.(RW.II). 13,.46
Gyms. 22
HHalogenated.organic.compounds. 43
Hand.disinfection. 122
Hazardous.Substances.Ordinance..
(Gefahrstoffverordnung). 8,.16
Head.lice. 70
Health.evaluations.of.particulate..
matter.in.indoor.environments. 62
Health.impact.of.dusts. 60
Health.problems.in.a.new.wing. 109
Heating. 18
Heat-retaining.components. 90
Home.Economics.practical.areas. 33
Hot.water.temperatures. 70
House.dust.mites. 68
Humidifiers. 70,.72
Hypochlorite.compounds. 26
IIll-fitting.windows. 11Indoor.Air.Hygiene.Commission..(Innenraumlufthygiene-.Kommission,.IRK). 13Indoor.acoustic.properties. 96Indoor.air.quality.in.schools. 7Indoor.contamination.with..dibasic.dimethyl.esters. 107Indoor.air.temperatures. 91Indoor.fountains. 72Inorganic.gases. 35Isobutanol. 42Isobutyl.acetate. 43Isocyanates. 79Isopropanol. 42
KKitchens. 22,.122
LLaboratories. 18,.32Laminate.floors. 76Laser.printers. 34,.62Legionella. 27,.70Light.conditions,.Lighting. 11Linoleum. 21,.42Linoleum.floor.coverings. 76Lime-sand.bricks. 77Limonene. 41Load-bearing.timber.components. 78Low-emission.floor.covering..adhesives. 83Low-formaldehyde. 78,.85Lung.cancer. 65
MMechanical.disturbance. 60Mechanical.ventilation. 92
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Melamine-formaldehyde..adhesive.resin. 52Mesothelioma. 65Methyl.polysiloxanes. 43Micro-organisms. 68Mineral.fibres.from.suspended..ceiling.construction. 102Mineral.wool. 65Mineral.wool.products. 67Minimum.cleaning.frequencies. 20Minimum.requirements.for..cleaning.school.buildings. 19Minor.building.works. 28Moisture.damage. 69Mono-.and.dichloronaphthalenes. 59Mono-.to.trichloronaphthalenes. 43Mould. 68Mould.attack. 69Mould.damage. 68,.71Mould.growth.in.schools. 69,.44MVOCs. 44Mycotoxins. 71
NNaphthalene. 41Natural.air.exchange. 24Natural.ventilation. 92Need.for.remediation. 58,.68,.113Necessary.air.exchange. 25n-hexanal. 42Night.ventilation. 91Nitrogen.dioxide.(NO
2). 35,.38
Nitric.oxide.(NO). 38Nitrogen.oxides.(NO
x). 38,.33
Noise.insulation. 17Nonane. 40Non-specific.complaints. 45
OOctadecane. 40Odours. 29Odour.active.volatile.organic..compounds. 44
Odour.emissions. 30Odour.pollution.in.classrooms. 104Office.furniture. 85Olefins. 41Organophosphate.esters.(OPEs). 54OSB.panels. 78OVOCs. 44Ozone.(O
3). 34,.35,.39
PPAHs. 59PAH.concentrations. 114PAH.contamination.by.wood.-.block.floors. 114PAH.lead.substance. 59Particles. 34Particle.board. 59,.78Particle.size. 60Particulate.matter. 60Particulate.sources. 61PCBs. 54,.55,.112PCB.congeners. 55PCB.Guidelines. 56ff,.112ffPCB.remediation. 57p-dichlorobenzene. 43Pentachlorophenol. 57,.113Pettenkofer.number. 35Phenol-formaldehyde..adhesive.resins. 52Phosphoric.acid.esters. 54Phthalates. 55Pivot-hung.windows. 92PM.2.5. 63Polychlorinated.biphenyls..(PCBs). 54,.55,.112Polycyclic.aromatic.hydrocarbons.(PAHs). 54,.59,.114Polyurethane.glues. 53Porous.concrete.blocks. 77Preservatives. 82Preservatives.in.cans. 82Pressed.cork.products. 42Printers. 34
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Procedural.model.for..indoor.guideline.values. 46Propanal. 43Propanol. 42Propiconazole. 58Pseudomonas.aeruginosa. 27Pulmonary.alveoli. 60
QQuaternary.ammonium.compounds.(QUATS). 23
RRadiation. 72Radon. 73Radon.risk.inside.buildings. 73Recirculated.air. 92Rendering.mortar. 77Renovations. 11,.29Reverberation.time. 95,.96Risk.of.lung.cancer. 73Rockwool. 65
SSanitary.facilities. 84Sawdust. 32School.furniture. 85School.offices. 22School.swimming.pools. 26Sealing.compounds. 40,.55Sealants.containing.PCBs. 112Sedimentary.particles. 60Semi-volatile.organic.compounds.(SVOCs). 54Silicate.paints. 82Siloxanes. 43SMF. 63,.65SMF.fibres.of.critical.size. 66Smoke.production. 32Softeners. 54,.55Solar.radiation. 89
Solvent-based.cleaning.products..on.wood.floors. 106Staffrooms. 22Stairwells. 20Structural.noise.insulation. 17Sun-protection.devices. 90Surface.disinfection. 20,.123Styrene. 41SVOCs. 31,.39,.54Synthetic.mineral.fibres. 63,.65
TTall.resins. 83Tall.oils. 83Tar-based.adhesives. 59Tar.products. 59Tebuconazole. 58Technology.lessons. 61Thermal.conduction. 86Thermal.radiation. 87Terpene.alcohols. 41Tetradecane. 40Texanol. 43Timber.cladding. 57Titanium.dioxide. 82Tobacco.smoke. 12,.59Toilets. 18Toluene. 41Toner.cartridge.changing. 34Toner.particles. 34Total.PCBs. 56Total.volatile.organic.compounds. 47Transparent.window.area. 89Treatment.of..swimming.pool.water. 27Trihalogen.methanes. 26TSPs. 60Tuberculosis.bacteria. 69TVOCs. 39TVOC.evaluation. 47TVOC.values. 48
10.140_UBA_Schule_engl_04_RZ.indd 133 22.03.11 09:45
134
UUltra-fine.particles. 34Ultra-fine.particulate.matter. 34,.60Urea-formaldehyde-resins..adhesives. 52,.79
VVarnishing.parquet.floors. 81Ventilating. 21,.24Ventilation.requirements..for.workshops. 32Ventilation.technology. 92Ventilation.through.windows. 24,.92VOC.emissions. 29,.30Volatile.organic.compounds..(VOCs).. 31,.34,.39,.40,.47VVOCs. 39
WWall.paints. 82Wart/verruca.infections. 27Washbasins. 22,.23Washing. 19Washrooms. 22Windowless.rooms. 12Working.Group.of.the..Supreme.Health.Authorities.of..the.Federal.States. 13,.35,.46Workshops. 32Wood. 57,.78Wood-based.materials. 52,.59Wood.glazes. 81Wood.preservatives. 52,.59Woodworking.machinery. 32
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10.140_UBA_Schule_engl_04_RZ.indd 135 22.03.11 09:45
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10.140_UBA_Schule_engl_04_RZ.indd 136 22.03.11 09:45
Tabe
lle 6
: Hyg
ieni
sche
Bew
ertu
ng v
on T
VOC-
Wer
ten
und
dara
us r
esul
tier
ende
Em
pfeh
lung
en fü
r M
aßna
hmen
(Um
wel
tbun
desa
mt
2007
)
Stuf
eKo
nzen
trat
ions
bere
ich
[mg/
m3 ]
Hygi
enis
che
Bew
ertu
ngzu
klä
rend
e Fr
agen
Empf
ehlu
ngen
1≤
0,3
mg/m
3
Hyg
ien
isch
un
bed
enk
lich
. In
der
Reg
el k
ein
e Bes
chw
erden
.
Lieg
en R
ich
twer
tüber
sc
hre
itun
gen
vor?
Kei
ne
wei
tere
n M
aßn
ahm
en.
2>
0, 3
–1 m
g/m
3
Hyg
ien
isch
noch
un
be
den
klic
h, s
owei
t ke
ine
Ric
htw
ertü
ber
sch
rei
tun
gen
fü
r Ei
nze
lsto
ffe
bzw
. Sto
ffgru
ppen
vo
rlie
gen
.
In E
inze
lfäl
len
Be
sch
wer
den
oder
Ge
ruch
swah
rneh
mun
gen
, z.
B. n
ach
kle
iner
en
Ren
ovie
run
gsm
aßn
ah
men
oder
Neu
möb
lie
run
gen
in
den
let
zten
W
och
en.
Lieg
en R
ich
twer
tüber
sc
hre
itun
gen
vor
? Li
egen
auff
ällige
Ref
eren
zw
ertü
ber
sch
reit
un
gen
vo
r?
Sin
d d
ie r
aum
klim
ati
sch
en B
edin
gun
gen
(L
uft
wec
hse
l, Te
m
per
atur,
Luft
feuch
te)
ein
wan
dfr
ei?
Ausr
eich
end L
üft
en b
eson
der
s n
ach
Ren
ovie
ru
ngsa
rbei
ten
.
VO
CQ
uel
len
erm
itte
ln (z.
B. B
egeh
un
g
des
Rau
mes
).
Ver
wen
dun
g v
on
Putz
un
d R
ein
igun
gsm
itte
ln
über
prü
fen
.
Nac
hm
essu
ngen
zur
Kon
trolle
von
Ric
htw
ert
über
sch
reit
un
gen
un
ter
Nutz
un
gsb
edin
gun
gen
(s
. Kap
. 9).
3>
1–3
mg/m
3
Hyg
ien
isch
au
ffäl
lig.
Nu
tzu
ng b
ei R
äum
en,
die
reg
elm
äßig
gen
utz
t w
erden
, nu
r bef
rist
et
akze
pta
bel
(<
12
Mon
ate)
.
Inn
erh
alb v
on
ca.
6
Mon
aten
sollte
n T
VO
C
Kon
zen
trat
ion
deu
tlic
h
un
ter
den
an
fan
gs
gem
esse
nen
TV
OC
W
ert
abges
enkt
w
erden
.
Fälle
mit
Bes
chw
erden
oder
Ger
uch
swah
rn
ehm
un
gen
, z. B
. nac
h
grö
ßere
n R
enov
ie
run
gsa
rbei
ten
.
Lieg
en R
ich
twer
tüber
sc
hre
itun
gen
vor?
Lieg
en a
uff
ällige
Ref
ere
nzw
ertü
ber
sch
reit
un
gen
vor?
Sin
d d
ie r
aum
klim
ati
sch
en B
edin
gun
gen
(L
uft
wec
hse
l, Te
m
per
atur,
Luft
feuch
te)
ein
wan
dfr
ei?
Ric
htw
ertü
ber
sch
reit
un
gen
um
geh
end d
urc
h
Nac
hm
essu
ng u
nte
r N
utz
un
gsb
edin
gun
gen
ko
ntr
ollie
ren
un
d b
ei d
er B
ewer
tun
g d
ie H
in
wei
se in
Kap
. 4 b
erück
sich
tigen
.
Auff
ällige
Ref
eren
zwer
tüber
sch
reit
un
gen
auf
ges
un
dh
eitl
ich
e R
elev
anz
prü
fen
.
In jed
em F
all: Q
uel
len
such
e durc
hfü
hre
n u
nd
Lüft
un
gsv
erh
alte
n ü
ber
prü
fen
: in
ten
siv
lüft
en
un
d g
gf. N
utz
un
gs
un
d L
üft
un
gsb
edin
gun
gen
fe
stle
gen
.
Kon
trollm
essu
ng b
zw. N
ach
mes
sun
g n
ach
ca
. 1 M
on
at e
mpfo
hle
n (u
nte
r N
utz
un
gsb
edin
gun
gen
).
Lieg
t n
ach
12
Mon
aten
tro
tz d
er b
esch
rieb
enen
Bem
üh
un
gen
die
TV
OC
Kon
zen
trat
ion
wei
terh
in
über
1 m
g/m
3 , s
o s
ind a
däq
uat
e Sa
nie
run
gsm
aß
nah
men
in
die
wei
tere
Pla
nun
g a
ufz
un
ehm
en.
4>
3–10
mg/m
3
Hyg
ien
isch
bed
enkl
ich
Nu
tzu
ng b
ei R
äum
en,
die
reg
elm
äßig
gen
utz
t w
erden
, nu
r bef
rist
et
akze
pta
bel
(<
1 M
on
at).
Die
TV
OC
Kon
zen
tra
tion
sollte
in
ner
hal
b
ein
es M
on
ats
un
ter
3 m
g/m
3 ab
ges
enkt
w
erden
.
Fälle
mit
Häu
fun
g v
on
Bes
chw
erden
oder
G
eru
chsw
ahrn
ehm
un
gen
, z. B
. nac
h g
röße
re
n R
enov
ieru
ngsa
rbei
ten
.
Lieg
en R
ich
twer
tüber
sc
hre
itun
gen
vor?
Lieg
en a
uff
ällige
Ref
ere
nzw
ertü
ber
sch
reit
un
gen
vor?
Sin
d d
ie r
aum
klim
ati
sch
en B
edin
gun
gen
(L
uft
wec
hse
l, Te
m
per
atur,
Luft
feuch
te)
ein
wan
dfr
ei?
Ric
htw
ertü
ber
sch
reit
un
gen
um
geh
end d
urc
h
Nac
hm
essu
ng u
nte
r N
utz
un
gsb
edin
gun
gen
ko
ntr
ollie
ren
un
d b
ei d
er B
ewer
tun
g d
ie H
in
wei
se in
Kap
. 4 b
erück
sich
tigen
.
Auff
ällige
Ref
eren
zwer
tüber
sch
reit
un
gen
auf
ges
un
dh
eitl
ich
e R
elev
anz
prü
fen
. Tox
ikolo
gis
che
Bew
ertu
ng v
on
Ein
zels
toff
en o
der
Sto
ffgru
ppen
er
ford
erlich
.
In jed
em F
all: Q
uel
len
such
e durc
hfü
hre
n u
nd
inte
nsi
v lü
ften
un
d g
gf. N
utz
un
gs
un
d L
üf
tun
gsb
edin
gun
gen
fes
tleg
en u
nd g
eeig
net
e M
inim
ieru
ngsm
aßn
ahm
en v
eran
lass
en. E
in
ggf. n
otw
endig
er A
ufe
nth
alt
ist
nur
mit
zei
tlich
er B
esch
rän
kun
g p
ro T
ag ü
ber
ein
en v
om
G
esun
dh
eits
amt
vorz
ugeb
enden
max
imal
en
Zei
trau
m (pro
Tag
stu
nden
wei
se/z
eitl
ich
bef
rist
et) to
lera
bel
.
Kon
trollm
essu
ng b
zw. N
ach
mes
sun
g n
ach
ca
. 1 M
on
at e
mpfo
hle
n (u
nte
r N
utz
un
gsb
edin
gun
gen
).
Lieg
t n
ach
1 M
on
at t
rotz
der
bes
chri
eben
en
Bem
üh
un
gen
die
TV
OC
Kon
zen
trat
ion
wei
ter
h
in ü
ber
3 m
g/m
3 , s
o s
ind a
däq
uat
e Sa
nie
run
gs
maß
nah
men
in
die
wei
tere
Pla
nun
g a
ufz
un
eh
men
.
5>
10–2
5 m
g/m
3
Hyg
ien
isch
in
akze
p
tabel
.
Rau
mn
utz
un
g m
ög
lich
st v
erm
eiden
. Ein
A
ufe
nth
alt
ist
alle
nfa
lls
pro
Tag
stu
nden
wei
se
/zei
tlic
h b
efri
stet
zu
läss
ig.
Bei
Wer
ten
ober
hal
b
von
25
mg/m
3 is
t ei
ne
Rau
mn
utz
un
g z
u
un
terl
asse
n.
Die
TV
OC
Kon
zen
tra
tion
sollte
in
ner
hal
b
ein
es M
on
ats
un
ter
3 m
g/m
3 ab
ges
enkt
w
erden
.
In d
er R
egel
Bes
chw
er
den
un
d G
eru
chsw
ahr
neh
mu
ngen
z. B
. nac
h
Feh
lan
wen
du
ngen
, U
nfä
llen
.
Lieg
en a
uff
ällige
R
efer
enzw
ertü
ber
sc
hre
itun
gen
vor?
Lieg
en R
ich
twer
tüber
sc
hre
itun
gen
vor?
Sin
d d
ie r
aum
klim
ati
sch
en B
edin
gun
gen
(L
uft
wec
hse
l, Te
m
per
atur,
Luft
feuch
te)
ein
wan
dfr
ei?
Ric
htw
ertü
ber
sch
reit
un
gen
um
geh
end d
urc
h
Nac
hm
essu
ng u
nte
r N
utz
un
gsb
edin
gun
gen
ko
ntr
ollie
ren
un
d b
ei d
er B
ewer
tun
g d
ie H
in
wei
se in
Kap
. 4 b
erück
sich
tigen
.
Auff
ällige
Ref
eren
zwer
tüber
sch
reit
un
gen
auf
ges
un
dh
eitl
ich
e R
elev
anz
prü
fen
. Tox
ikolo
gis
che
Bew
ertu
ng v
on
Ein
zels
toff
en o
der
Sto
ffgru
ppen
er
ford
erlich
.
In jed
em F
all: Q
uel
len
such
e durc
hfü
hre
n u
nd
inte
nsi
v lü
ften
un
d N
utz
un
gs
un
d L
üft
un
gs
bed
ingun
gen
fes
tleg
en u
nd g
eeig
net
e M
ini
mie
run
gsm
aßn
ahm
en v
eran
lass
en. E
in g
gf.
notw
endig
er A
ufe
nth
alt
ist
nur
mit
zei
tlic
her
Bes
chrä
nku
ng p
ro T
ag ü
ber
ein
en v
om
G
esun
dh
eits
amt
vorz
ugeb
enden
max
imal
en
Zei
trau
m (pro
Tag
stu
nden
wei
se/z
eitl
ich
bef
rist
et) to
lera
bel
.
Kon
trollm
essu
ng b
zw. N
ach
mes
sun
g in
ner
hal
b
von
1 M
on
at (un
ter
Nutz
un
gsb
edin
gun
gen
).
Wir
d d
urc
h M
inim
ieru
ngsm
aßn
ahm
en
10 m
g/m
3 im
bet
rach
tete
n Z
eitr
aum
zw
ar
un
ters
chri
tten
, ein
e K
on
zen
trat
ion
von
3 m
g/m
3 al
lerd
ings
wei
terh
in ü
ber
sch
ritt
en, g
elte
n
die
Maß
nah
men
empfe
hlu
ngen
wie
un
ter
St
ufe
4. L
iegt
nac
h 1
Mon
at t
rotz
der
bes
chri
ebe
nen
Bem
üh
un
gen
die
TV
OC
Kon
zen
trat
ion
wei
te
rhin
über
10
mg/m
3 , s
o s
ollte
die
Rau
mn
utz
un
g
un
ter
ble
iben
un
d e
s si
nd a
däq
uat
e Sa
nie
run
gs
maß
nah
men
zu v
eran
lass
en.
08.115_UBA_Schule_Ausklapper_03_RZ.indd 1 26.11.2008 11:14:13 Uhr
| UMWELT & GESUNDHEIT |
GUIDELINES FOR INDOOR AIR HYGIENE IN SCHOOL BUILDINGS
Guid
elin
es fo
r In
door
Air
Hyg
enie
in S
choo
l Bui
ldin
gs
Edi
tion
200
8
Contact: Federal Environment AgencyPostfach 140606813 Dessau-RoßlauInternet: www.umweltbundesamt.de E-mail: [email protected] Printed on 100% recycled paper