Chlorofluorocarbons. Ozone protects us from the harmful UV radiations from the sun. Major pollutants responsible for the depletion of ozone layer are chlorofluorocarbons, nitrogen oxides and hydrocarbons CFCs are widely used as coolants in air conditioners and refrigerators, cleaning solvents, aerosol propellants and in foam insulation. The threat to $O_{3}$ is mainly from CFCs, which are known to deplete $O_{3}$ by 14% at the current emission rate