Phase-Out of Ozone Depleting and Chemicals

The United States signed the Montreal Protocol on Substances that Deplete the Ozone Layer, which is an international agreement to reduce and eventually ban the production of most ozone depleting chemicals. In order to implement this agreement in the U.S., Congress passed the Clean Air Act of 1990. This directed the EPA to implement regulations to phase out CFCs and HCFCs.



The production of CFCs for air conditioning and refrigeration in the United States was banned in 1995. CFCs are much more harmful to the environment than HCFCs, but HCFCs are next in line for elimination. The chart above shows how much and when the United States must reduce use of ozone depleting HCFCs such as R-22.

The impact on the ozone layer for every HCFC chemical such as R-22 has been estimated and compared to that of CFC-11. This impact is called its "Ozone Depletion Potential" or "ODP". For R-22, this number is 0.055 because it is 5-1/2% as ozone depleting as R-11 over a 100 year period. There are many other ozone-depleting HCFCs, such as "141b" which is used for insulating refrigerators and houses. Production of HCFC-141b in the U.S. has already been banned and other HCFCs are scheduled to be phased out.