CFC, chlorofluorocarbon, is the collective name for compounds made of carbon, fluorine, chlorine and hydrogen. Because of their stable, harmless and non-combustible properties, they are widely used in everyday applications such as cleansing agents for electronic components, coolants for air conditioners, foaming agents for the manufacture of insulating materials and so on. CFC variations include HCFC and HFC.
1.CFC (Chlorofluorocarbon)
Because of CFC's strong ozone layer-destroying effect, its production was totally banned at the end of 1995.
It is necessary to ensure proper handling of CFC in appliances currently in use.
2.HCFC (Hydrochlorofluorocarbon)
Although less powerful than CFC in destroying the ozone layer, HCFC must be also contained.

Mechanism of ozone layer destruction by CFCs
Since CFCs are chemically stable, when released into the atmosphere they pass through the troposphere at about 20 km altitude without decomposing, reaching the stratosphere, where they are chemically decomposed by short-wavelength ultraviolet rays, releasing chlorine atoms. In a chain reaction, the chlorine atoms destroy the ozone layer in the stratosphere.