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Chlorofluorocarbons (CFCs)

CFCs

SPRI Emission Reporting Threshold
1.00 Kg/yr Pollutant Emissions to Air
Disclaimer
This sheet is a generic summary, designed to give the reader a basic level of background information about the substance in question. Great care has been taken to represent as effectively and correctly as possible the broad range of (not necessarily consistent) information which is available from a variety of sources. The reader must accept therefore that this sheet has no legal status and cannot be relied upon in any legal proceedings. SEPA disclaims any responsibility or liability whatsoever for errors and omissions in this sheet.
What is it?
Chlorofluorocarbons (CFCs) are a group of compounds which contain the elements chlorine, fluorine and carbon. At room temperatures, they are usually colourless gases or liquids which evaporate easily. They are generally unreactive and stable, non-toxic and non-flammable. CFCs are also a part of the group of chemicals known as the volatile organic compounds (VOCs).
What is it used for?
The properties of CFCs make them useful for a variety of commercial and industrial purposes: as a propellant in aerosol sprays (now banned in the US and Europe), in refrigeration and air conditioning systems, in foams, in cleaning solvents and in electrical components.
Where does it come from?
Most CFCs have been released to the atmosphere through the use of aerosols containing them and as leakages from refrigeration equipment. Other releases may occur from industry producing and using them and other products containing them. There are not thought to be any natural sources of CFCs to the environment.
How might it affect the environment?
CFCs are unlikely to have any direct impact on the environment in the immediate vicinity of their release. As VOCs, they may be slightly involved in reactions to produce ground level ozone, which can cause damage to plants and materials on a local scale. At a global level however, releases of CFCs have serious environmental consequences. Their long lifetimes in the atmosphere mean that some end up in the higher atmopshere (stratosphere) where they can destroy the ozone layer, thus reducing the protection it offers the earth from the sun's harmful UV rays. CFCs also contribute to Global Warming (through "the Greenhouse Effect"). Although the amounts emitted are relatively small, they have a powerful warming effect (a very high "Global Warming Potential").
How might exposure to it affect human health?
Chlorofluorocarbons enter the body primarily by inhalation of air containing chlorofluorocabons, but can also enter by ingestion of contaminated water, or by dermal contact with chlorofluorocarbons. Inhalation of high levels of chlorofluorocarbons can affect the lungs, central nervous system, heart, liver and kidneys. Symptoms of exposure to chlorofluorocarbons can include drowsiness, slurred speech, disorientation, tingling sensations and weakness in the limbs. Exposure to extremely high levels of chlorofluorocarbons can result in death. Ingestion of chlorofluorocarbons can lead to nausea, irritation of the digestive tract and diarrhoea. Dermal contact with chlorofluorocarbons can cause skin irritation and dermatitis. Chlorofluorocarbons are involved in the destruction of the stratospheric ozone layer resulting in increased exposure to UV radiation which is known to cause skin cancer. The International Agency for Research on Cancer has not designated chlorofluorocarbons as a group in terms of their carcinogenicity. The International Agency for Research on Cancer has designated chlorofluoromethane and chlorodifluoromethane as being not classifiable as to their carcinogenicity to humans. However, exposure to chlorofluorocarbons at normal background levels is unlikely to have any adverse effect on human health.
What steps are being taken to limit the potential impacts?
The main legislation controlling releases of CFCs is the Montreal Protocol, which came into force in 1987. This is an international agreement which obliged most signaturies to completely phase out their use of CFCs by 1996. Only developing countries were allowed to exceed this at a level of up to 15% of their production pre the signing of the Protocol. Releases in the UK are also controlled through the UK Pollution, Prevention and Control (PPC) Regulations.