Chlorofluorocarbon
(CFC): A
molecule
containing only chlorine, fluorine, and carbon. Used as
refrigerants, propellants, and blowing agents, but now banned
internationally by the
Montreal
Protocol. Connected with annual
ozone
holes over the Earth's Antarctic and Arctic regions.
HCFCs
(hydrofluorochlorocarbons) were initially used to replace
CFCs in many applications, because it was thought these
molecules
would degrade in the atmosphere before reaching the
ozone
layer. However recent studies suggest that HCFCs may also
lead to
ozone
depletion. HCFCs are now being replaced by
hydrofluorocarbons (HFCs).
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Dichlorodifluoromethane
(Freon-12),
a typical chlorofluorocarbon (CFC). |
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1,1-Dichloro-1-fluoroethane
(HCFC-141b),
a typical hydrochlorofluorocarbon (HCFC).
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1,1-Difluoroethane
(HFC-152a),
a typical hydrofluorocarbon (HFC).
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