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PHOENIXLOSS PREVENTION

CERTIFICATION OF CERTIFICATION OF EQUIPMENT FOR USE IN EQUIPMENT FOR USE IN POTENTIALLY EXPLOSIVE POTENTIALLY EXPLOSIVE ATMOSPHERESATMOSPHERES

What do I Really Have to Do ?


UK’S IMPLEMENTATION OF UK’S IMPLEMENTATION OF ATEXATEX

1999/92/EC – ATEX 137 – Implemented as The Dangerous Substances and Explosive Atmospheres Regulations 2002 (DSEAR) – Social Directive

94/9/EC – ATEX 100 – Implemented as the Equipment and Protective Systems for Use in Potentially Explosive Atmospheres Regulations 1996 (EPS) – Trade Directive


DUTIES UNDER DSEARDUTIES UNDER DSEAR Conduct Risk Assessment relating to Explosive

Atmospheres and their potential threat to people – hazards from flammable gases and vapours and combustible dusts

Conduct Area Classification – define locations of Hazardous Areas in the workplace

Employ suitable Safety Management systems to ensure that an adequate level of explosion safety is maintained


SUPPLIER RESPONSIBILITIES SUPPLIER RESPONSIBILITIES UNDER EPSUNDER EPS

Assess risks associated with equipment to demonstrate it is safe for use

Ensure that equipment supplied for use in areas defined as hazardous by the customer is suitably certified for the type of hazardous area in which it will be installed

Must consider all potential ignition sources – e.g. flames, sparks, static, etc – not just electrical ignition sources


Supplier’s Responsibilities (cont)Supplier’s Responsibilities (cont)

Ensure equipment is suitably labelled

Maintain a technical file and quality records re production

Provide instructions for Installation, Maintenance, Inspection and Use


Operator’s Responsibilities when Operator’s Responsibilities when OrderingOrdering

– Tell the supplier what classification of hazardous area the equipment will be installed in

– Tell the supplier if the equipment is to be connected to other equipment which may contain an explosive atmosphere

– Tell the supplier what material the equipment will handle (if it is processing material) and provide information on material properties


Information on Material Information on Material PropertiesProperties

As a minimum– Whether the material can support an explosion (gas or dust)– Physical characteristics – Gas – autoignition temperature– Dust - Layer Ignition Temperature & Minimum Cloud Ignition

Temperature Other data which the supplier may need to request

(depending on how equipment is to be protected)– Minimum Ignition Energy– Explosion Indices


CUSTOMER MUST PROVIDE CUSTOMER MUST PROVIDE INFORMATION ON HAZARDOUS INFORMATION ON HAZARDOUS

AREASAREAS

WHAT IS A HAZARDOUS AREA?WHAT IS A HAZARDOUS AREA?

“A place in which an explosive atmosphere may occur in sufficient quantities to require special precautions to protect the health and safety of the workers concerned is deemed to be hazardous”

“A place in which an explosive atmosphere is not expected to occur in such quantities to require special precautions is deemed to be non-hazardous within the meaning of these Regulations”


HAZARDOUS AREA HAZARDOUS AREA DEFINITIONS UNDER DSEARDEFINITIONS UNDER DSEAR

Zone 0 (20): A place in which an explosive atmosphere consisting of a mixture with air of flammable substances in the form of gas, vapour or mist (or dust) is present continuously or for long periods or frequently.

Zone 1 (21): A place in which an explosive atmosphere consisting of a mixture with air of flammable substances in the form of gas, vapour or mist (or dust) is likely to occur in normal operation occasionally.

Zone 2 (22): A place in which an explosive atmosphere consisting of a mixture with air of flammable substances in the form of gas, vapour or mist (or dust) is not likely to occur in normal operation but, if it does occur, will persist for a short period only.


Problems re Classification of Problems re Classification of Hazardous AreasHazardous Areas

Customers tend to be conservative and “over-classify” hazardous areas

Customers may not have classified hazardous areas

Zone 0/20 & 1/21 require that explosive concentrations are present in normal operation (e.g. >20,000ppm or 50g/m3)

Majority of workplaces will be no worse than Zone 2/22 (and may be safe)

Need to include the new equipment in the evaluation of workplace hazardous areas – ideally operator would consult with supplier

Be prepared to challenge the customer’s area classification


Classification of Gas Hazardous Classification of Gas Hazardous AreasAreas

Tendency is to be too conservative (e.g. extent of flammable atmosphere above flammable liquids will generally be small)

Historical “Flameproof” areas might not be zone 1

Take credit for ventilation

T AB L E 3 .1 : INFL U ENC E O F VEN TIL AT IO N O N T YPE O F Z O NE

Gra de o frelease

Ventilatio n

D egree

H igh M ed ium Low

A v a i l a b il i ty

G o o d F a i r P o o r G o o d F a i r P o o r G o o d , fa i ro r p o o r

Con tin uou s ( Z o n e 0 N E )

N o n -h a za rd o u s 1 )

( Z o n e 0 N E )

Z o n e 2 1 )

( Z o n e 0 N E )

Z o n e 1 1 )

Z o n e 0 Z o n e 0 +Z o n e 2

Z o n e 0 +Z o n e 1

Z o n e 0

Prim ary ( Z o n e 1 N E )


( Z o n e 1 N E )

Z o n e 2 1 )

( Z o n e 1 N E )

Z o n e 2 1 )

Z o n e 1 Z o n e 1 +Z o n e 2

Z o n e 1 +Z o n e 2

Z o n e 1 o rZ o n e 0 3 )

Secondary 2)2) ( Z o n e 2 N E )


( Z o n e 2 N E )


Z o n e 2 Z o n e 2 Z o n e 2 Z o n e 2 Z o n e 1a n d e v e nZ o n e 0 3 )

1 ) Z o n e 0 N E , 1 N E o r 2 N E in d ic a t es a t h eo re t ic a l zo n e w h ic h w o u ld b e o f n eg l ig ib le e x t en tu n d e r n o rm a l co n d it io n s .

2 ) T h e zo n e 2 a rea c rea t ed b y a s e co n d a ry g rad e o f re le as e m a y e x c ee d t h a t a tt r ib u t ab le t o ap r i m a ry o r co n t in u o u s g ra d e o f re le a s e ; i n w h ic h c as e , t h e g re a t e r d is t an ce s h o u ld b e t a k e n .

3 ) W il l b e zo n e 0 if t h e v e n t il a t io n is s o w e a k an d th e re le a s e is s u ch th a t in p ra c t ic e ane x p lo s iv e a t m o s p h e re e x is ts v ir t u a lly co n t in u o u s l y ( i . e . a p p ro ac h in g a “ n o v en t ila t io n ”c o n d it io n ) .

N O T E - “ + ” s ig n i f ie s “s u r ro u n d e d b y ” .


EXPLOSIVE DUST EXPLOSIVE DUST ATMOSPHEREATMOSPHERE

A cloud of 40 g/m3 of coal dust in air is so dense that a glowing 25W light bulb can hardly be seen through a dust cloud of 2m thickness


CLASSIFICATION OF CLASSIFICATION OF EQUIPMENTEQUIPMENT

You have agreed with your customer what You have agreed with your customer what the hazardous areas are – what do you the hazardous areas are – what do you

now have to do to classify your equipmentnow have to do to classify your equipment


Certification of Equipment for Certification of Equipment for Use in Hazardous AreaUse in Hazardous Area

1. Equipment which does not handle hazardous material – only need to address the potential for the equipment to ignite a surrounding explosive atmosphere

2. Equipment which handles hazardous material – have to address control of explosion risks inherent to the equipment, the potential to ignite a surrounding explosive atmosphere, and the potential to ignite an explosive atmosphere in connected equipment


Equipment Classification to EPSEquipment Classification to EPS

Category 3 – equipment which does not represent an ignition source in normal operation – suitable for use in zone 2 (22) area

Category 2 – equipment which does not create an ignition source in normal operation, or in the event of a foreseeable malfunction – suitable for use in zone 1 (21) and 2 (22) areas

Category 1 – equipment which does not create an ignition source even in the event of a rare malfunction – suitable for use in zone 0 (20, 1 (21) and 2 (22) areas


Authority to ClassifyAuthority to Classify Category 3 – self certification by supplier

Category 2, non-electrical ignition sources – self certification by supplier (technical file to be sent to a Notified Body)

Category 2, electrical ignition sources (or internal combustion engines) – certification by Notified Body

Category 1 – certification by Notified Body

Have to be clear if the equipment is certified for Gases (G) or Dusts (D) or both (G/D)


Equipment from Outside the ECEquipment from Outside the EC

For equipment manufactured in the EC the supplier is responsible for the certification

When equipment is imported from outside the EC it must still be certified, and either the EC agent (if there is one), or the EC customer has to take on the responsibilities of the supplier


Certification of EquipmentCertification of Equipment Have to consider the Machinery Directive as well as EPS

Do risk assessment for Machinery Directive first, then move on to EPS

Machinery Directive requires a demonstration that the equipment is safe for intended use – requires consideration of inherent explosion hazards – may determine that equipment requires explosion protection

Having completed the Machinery Directive risk assessment conduct an Ignition Hazard Assessment for EPS


Explosion Protection DevicesExplosion Protection Devices

Equipment Intended to provide protection against explosion affects, or to prevent explosion propagation from an item of equipment to another are “explosion protection devices” and must be Certified under EPS (by a notified body)

Examples are :– Relief panels– Suppression Systems– Explosion Barrier Valves– etc


Let’s look at how to classify the Let’s look at how to classify the two types of equipment (that two types of equipment (that

which does not handle a which does not handle a flammable material and that flammable material and that

which does)which does)


Equipment which does not Equipment which does not handle Hazardous Materialhandle Hazardous Material

Machinery Directive assessment will concentrate on basic health and safety requirements (e.g. guarding) and will not touch on EPS matters

Ignition Hazard Assessment required to categorise equipment depending on its ability to ignite a surrounding explosive atmosphere


Ignition Hazard AssessmentIgnition Hazard Assessment Systematically review the operation of the equipment to identify

conditions when ignition sources could arise

Consider all potential sources of ignition (e.g. electrical & mechanical sparks, friction / hot surfaces, static)

Consider normal (intended) operation first

Identify foreseeable malfunctions and decide whether these could create ignition sources (considering ignition of a surrounding explosive atmosphere)

Identify rare malfunctions (e.g. two simultaneous malfunctions) and decide whether these could create ignition sources

BS EN 13463 provides a methodology


Possible Outcomes of Ignition Possible Outcomes of Ignition Hazard AssessmentHazard Assessment

1. Equipment provides an ignition source in normal operation – can’t certify under EPS (need to look at measures to remove the ignition source)

2. Equipment provides an ignition source as a result of a foreseeable malfunction – self certify as Category 3

3. Equipment provides an ignition source as a result of a rare malfunction – self certify as Category 2 (if no electrical ignition sources). If machine has some electrical components then invite Notified Body to certify, or use pre-certified category 1 or 2 electrical components in the assembly - lodge technical file with Notified Body

4. Equipment does not provide an ignition source in the event of a rare malfunction – invite Notified Body to certify as category 1


Further ConsiderationsFurther Considerations

Creation of sparks or hot surfaces inside equipment may ignite a surrounding explosive atmosphere if there is no isolation

Have to consider how the equipment might be used (abused) by the customer – may need some additional controls to prevent inadvertent incorrect use – or some warnings in instructions provided with the machine


Equipment Handling a Hazardous Equipment Handling a Hazardous MaterialMaterial

Conduct Machinery Directive Risk Assessment– Identify causes of explosive atmosphere within equipment– Look for possible sources of ignition of any such

atmospheres– Determine whether ignition sources can be adequately

controlled– Decide whether explosion protection is needed (will depend

on overall risk – frequency and consequences)– Define explosion protection controls

Complete Ignition Hazard Assessment in relation to an explosive atmosphere surrounding the equipment, and any explosive atmospheres in items which will be connected to the equipment, taking into account controls defined by the Machinery assessment


Implications of Internal IgnitionsImplications of Internal Ignitions Ignition of an explosive atmosphere within an item of

equipment may create an ignition source to an explosive atmosphere surrounding the equipment, if there is no isolation

e.g. assessment of components on the outside of the equipment might allow Category 2, but internal ignition from a foreseeable malfunction would reduce this to Category 3 if flame can propagate from inside to outside

Isolation devices will be “explosion protection devices” under EPS and will have to be certified by a notified body


Transfer of Ignition Sources to Transfer of Ignition Sources to Connected EquipmentConnected Equipment

“Internal” classification of machine (i.e. likelihood of ignition sources to up- and down-stream equipment) may be different to external classification

If internal classification is not compatible with hazardous area classification for connected items will have to advise the customer that the connected items require explosion protection


Key Problems with the Key Problems with the RegulationsRegulations

Many suppliers are not confident enough to self certify equipment

Operators tend to overstate the hazardous areas

Difficult to take into account the different ignition and combustion properties of different materials

Assistance from Notified bodies can be expensive


EXAMPLE – Hammer MillEXAMPLE – Hammer Mill Zone 22 workplace, Category 3D

mill required as a minimum But internal explosive atmosphere

in normal operation identified by the Machinery Risk Assessment, and possible ignition source in the event of a malfunction

Large volume grist hopper – consequences of explosion could be severe

Explosion protection required EPS certified explosion barriers

required to prevent explosion protection to connected equipment (which might also contain explosive atmospheres)


So if my risk assessment So if my risk assessment determines that my equipment determines that my equipment requires explosion protection requires explosion protection

what can I do ?what can I do ?


Explosion ProtectionExplosion Protection Explosion Containment

– design plant for maximum explosion pressure

Explosion Suppression– install extinguishing system

Explosion Venting– provide weak panel to relieve pressure

Explosion Isolation– prevent explosion propagation

In all cases would have to use Certified Devices approved by a Notified Body


MYTH MYTH Existing equipment must be replaced Existing equipment must be replaced

by ATEX approved equipmentby ATEX approved equipmentEquipment on the market before 1st July 2003

exempt from EPS (ATEX 100)– i.e. already installed, second hand or in stores

Equipment must be safe for use in hazardous areas– e.g. old “Ex” rated electrical equipment in

gas/liquid zones & suitable ‘IP’ rating for dust zones – suitable surface temperatures in both cases


MYTH MYTH Existing protective systems must be Existing protective systems must be replaced by ATEX certified systemsreplaced by ATEX certified systems

Protective systems on the market before 1st July 2003 are exempt from EPS – Aluminium panels

secured by nylon bolts– Explosion Doors with

Brixon Latches OK to retain so long as

they provide effective protection


OTHER AREAS OF OTHER AREAS OF CONFUSIONCONFUSION

Maintenance of Certified Equipment– Under EPS Suppliers must provide essential information for

operation and maintenance – qualified technicians should be able to perform all necessary maintenance

Refurbishing Old Equipment– Can legitimately refurbish equipment back to its original

state without having to certify it – only have to certify if functionality is changed

Use of Plastic in Hazardous areas– No restriction in zone 2/22 areas


SUMMARYSUMMARY Operator is responsible for Area Classification and must tell

the Supplier what classification of hazardous area equipment will be required to operate in, and whether it will be connected to hazardous areas in other equipment

Be prepared to challenge the Customer’s area classification

Most equipment will be going into zone 2 (22) areas at worst, so can self certify

Conduct Machinery Assessment first to define any explosion controls, then conduct Ignition Hazard Assessment

Suppliers should provide instructions for safe operation which should cover maintenance as well

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