A classification for chemical compounds which contribute to the loss of ozone in the kupper atmosphere; majore examples include: chlorofluorocarbons, hydrochlorofluorocarbons, halons, methyl bromide, carbon tetrachloride, and methyl chloroform.

They are generally stable in the troposphere and only degrade under intense ultraviolet light in the stratosphere, at which time they release chlorine or bromine atoms, which in turn deplete the ozone.