EPA Collaborations with Stakeholders to Protect the Ozone Layer

As a Party to the Montreal Protocol on Substances that Deplete the Ozone Layer, the United States joined with other nations to phase out the production and use of ozone-depleting substances ( ODS ODS A compound that contributes to stratospheric ozone depletion. ODS include chlorofluorocarbons (CFCs), hydrochlorofluorocarbons (HCFCs), halons, methyl bromide, carbon tetrachloride, hydrobromofluorocarbons, chlorobromomethane, and methyl chloroform. ODS are generally very stable in the troposphere and only degrade under intense ultraviolet light in the stratosphere. When they break down, they release chlorine or bromine atoms, which then deplete ozone. A detailed list of class I and class II substances with their ODPs, GWPs, and CAS numbers is available. ) that harm the ozone layer. EPA continues to work with stakeholders to coordinate global and national efforts to protect the ozone layer: