Ozone depleting substances are chemicals which, when released into the atmosphere accumulate in the ozone layer and react with the ozone molecules to destroy them. The main ozone depleting substances are CFCs (chlorofluorocarbons), HCFCs (hydrochlorofluorocarbons), HBFCs (hydrobromofluorocarbons), halons, methyl bromide, methyl chloroform and carbon tetrachloride.

Chemicals that are stable within the troposphere (nearest atmosphere layer to ground surface) and contain one or more atoms of chloro, starts a chemical reaction the moment it reaches the stratosphere layer, which results in depleting the ozone atoms in this layer.

Ozone Depletion Potential ODP