Chlorofluorocarbons and ozone layers?

Question

What role do chlorofluorocarbons play in the catalytic destruction of the ozone layer?

Answer 1

Chlorofluorocarbons (CFC) are compounds containing chlorine, fluorine and carbon only, that is they contain no hydrogen. They were formerly used widely in industry, for example as refrigerants, propellants, and cleaning solvents. Their use has been regularly prohibited by the Montreal Protocol, because of effects on the ozone layer (see ozone depletion). They are also powerful greenhouse gases, in terms of carbon dioxide equivalence (over a time period of one hundred years) between 5000 and 8100 per kg. [1] CFCs have half-lives between 50-100 years, so their presence in the atmosphere and reactivity with ozone is long lived. One CFC molecule typically degrades around 10,000 ozone molecules before its removal, but this number can sometimes be in the millions.

Hydrochlorofluorocarbons (HCFCs) are of a class of haloalkanes where not all hydrogen has been replaced by chlorine or fluorine. They are used primarily as chlorofluorocarbon (CFC) substitutes, as the ozone depleting effects are only about 10% of the CFCs.