What are CFCs and why are they harmful?
Chlorofluorcarbons (CFCs) are the main culprits in the destruction of the stratospheric ozone layer. CFCs were first introduced in the 1920s as refrigerants and coolants, propellants for aerosol sprays, and cleaning solvents. CFCs are not easily degradable, so they rise up into the stratosphere where they are broken down by ultraviolet light. The chlorine atoms then destroy the ozone in a series of complex chemical reactions. One chlorine atom has the potential to destroy as many as 10,000 ozone molecules before it bonds with another atom and returns to the troposphere.
