State the chemicals responsible for ozone layer depletion.

Chemicals responsible for the depletion of the ozone layer are :

1. Excessive use of chlorofluoro carbons: CFCs (freons) enter the atmosphere because of their excessive use in solvents, aerosol sprays, propellants, refrigerants and blowing agents for plastic foams.
2. Fuel of planes: When the fuel of planes burns, a large quantity of nitric oxide and other gases is emitted in the atmosphere.
3. The chemicals used in industries like methyl chloride (CH₃Cl), methyl bromide (CH₃Br), carbon tetrachloride (CCl₄) also deplete ozone layer.