CFCs

Chlorofluorocarbons better known as CFCs are a type of hydrocarbon which have very useful properties. They aren't toxic or flammable and have a low boiling point. This means they are perfect to use as a refrigerant to replace ammonia which was used previously but was very smelly an toxic. CFCs can be produced to have a specific boiling point which is very useful.

CFCs were used as propellants in aerosols, as a blowing agent to create foam, as a refrigerant and as a cleaning solvent for electronic circuits.

With all these processes CFCs invariably escape into the atmosphere. CFCs being very unreactive can stay in the troposphere for over 100 years without breaking down giving them enough time to travel up into the stratosphere. There they are broken down by the fierce ultra violet rays. Chlorine radicals are formed. chlorine radicals catalyse the transformation of ozone back into oxygen. Each chlorine atom on average destroys 100 000 molecules of ozone.