Ozone DepletionOzone Depletion

Reducing the Reducing the manufacture and manufacture and

release of halogenated release of halogenated organic chemicalsorganic chemicals

What are halogenated What are halogenated organic chemicals?organic chemicals?

CFCs CFCs ChlorofluorocarbonsChlorofluorocarbons

HCFCsHCFCs HydrochlorofluorocarbonsHydrochlorofluorocarbons

CFCsCFCs

Can (in some cases used to) be found in:Can (in some cases used to) be found in: Aerosol spraysAerosol sprays Cleaning fluidsCleaning fluids FreezersFreezers Air conditionersAir conditioners RefrigeratorsRefrigerators Industrial solventsIndustrial solvents DehumidifiersDehumidifiers Foam insulationFoam insulation

HCFCsHCFCs

Are found in:Are found in: Heat pumpsHeat pumps Central air conditionersCentral air conditioners

A Brief History and StatusA Brief History and Status

1978 – US banned CFC’s as propellants in 1978 – US banned CFC’s as propellants in aerosol productsaerosol products

1987 – “Montreal Protocol on Substances 1987 – “Montreal Protocol on Substances that deplete the Ozone Layer” that deplete the Ozone Layer” International conference to control these International conference to control these chemicals. Signed by US and 22 other chemicals. Signed by US and 22 other countriescountries Limited production and use of CFC’sLimited production and use of CFC’s 50% reduction in CFC production worldwide 50% reduction in CFC production worldwide

by 2000by 2000

A Brief History and StatusA Brief History and Status

““Montreal Protocol on Substances Montreal Protocol on Substances that deplete the Ozone Layer”that deplete the Ozone Layer” Now signed by over 90 nationsNow signed by over 90 nations Revised to require the virtual Revised to require the virtual

phaseout of CFC production by 1996phaseout of CFC production by 1996 1990 – US “Clean Air Act 1990 – US “Clean Air Act

Amendment” passedAmendment” passed

Alternatives and Alternatives and ReplacementsReplacements

HCFCs (hydrochloroflurocarbon)HCFCs (hydrochloroflurocarbon) Positive aspects – Break down more Positive aspects – Break down more

quickly in the atmosphere posing less quickly in the atmosphere posing less danger to the ozone layerdanger to the ozone layer

Negative aspects – if overused they Negative aspects – if overused they could cause damage to the ozone could cause damage to the ozone layer in the same way as CFC’s. layer in the same way as CFC’s. Redesigned appliances could use Redesigned appliances could use more energy than the original modelsmore energy than the original models

Alternatives and Alternatives and ReplacementsReplacements

HFCs (Hydrofluorocarbons)HFCs (Hydrofluorocarbons) Positive aspects – do not contain Positive aspects – do not contain

chlorine and are therefore safe for the chlorine and are therefore safe for the ozone layerozone layer

Negative aspects – safety questions Negative aspects – safety questions such as flammability and toxicity still such as flammability and toxicity still unclearunclear

Alternatives and Alternatives and ReplacementsReplacements

Hydrocarbons (such as butane and Hydrocarbons (such as butane and propane)propane) Positive aspects - they are relatively Positive aspects - they are relatively

cheap and readily availablecheap and readily available Negative aspects – can be flammable Negative aspects – can be flammable

and poisonous and some increase and poisonous and some increase ground-level pollutionground-level pollution

Alternatives and Alternatives and ReplacementsReplacements

AmmoniaAmmonia Positive aspects – A simple alternative Positive aspects – A simple alternative

for refrigeratorsfor refrigerators Negative aspects – Must be handled Negative aspects – Must be handled

carefullycarefully

Alternatives and Alternatives and ReplacementsReplacements

Water (and Steam)Water (and Steam) Positive aspects – Effective for some Positive aspects – Effective for some

cleaning applicationscleaning applications

Other Options and Other Options and AlternativesAlternatives

Serious attempt at the control of Serious attempt at the control of the production, use, and emission the production, use, and emission of ozone-depleting chemicals of ozone-depleting chemicals world-wideworld-wide

Enforce by law and increase the Enforce by law and increase the recycling of these chemicalsrecycling of these chemicals

Enforce and regulate the servicing Enforce and regulate the servicing of refrigeration and air of refrigeration and air conditioning equipmentconditioning equipment

Other Options and Other Options and AlternativesAlternatives

Regulate and promote safe disposalRegulate and promote safe disposal Approve and enforce the use of Approve and enforce the use of

alternative chemicals that do not harm alternative chemicals that do not harm the ozonethe ozone

Regulate and enforce that CFCs and Regulate and enforce that CFCs and HCFCs are handeled legally when HCFCs are handeled legally when servicing or disposal of air conditionersservicing or disposal of air conditioners

Proper protection against the UV Proper protection against the UV radiation from the sunradiation from the sun

AssignmentAssignment

3.2.5: Research 1 national and 1 3.2.5: Research 1 national and 1 international agency/organization. international agency/organization. Be prepared to describe, compare, Be prepared to describe, compare, and evaluate their roles in the and evaluate their roles in the reduction of emissions of ozone-reduction of emissions of ozone-depleting substancesdepleting substances