What is leading to depletion of Ozone Layer in the atmosphere?

Many chemicals like Chlorine, Bromine and Chlorofluorocarbons are leading to depletion of Ozone Layer in the atmosphere. Chlorofluorocarbon compounds escape into the atmosphere and finally break down in the Stratosphere. They produce Chlorine atoms which destroy the Ozone layer.

Sulphur dioxide given out during volcanic eruptions, solar storms and human activities also lead to depletion of Ozone layer.