Stratospheric Ozone Depletion

In 1987, 27 countries signed the Montreal Protocol, a treaty that recognized the international nature of ozone depletion and committed the world to limiting the production of ozone-depleting substances. The 1990 Clean Air Act Amendments established a U.S. regulatory program to protect the stratospheric ozone layer. The amendments require the complete phase out of chlorofluorocarbons (CFCs) and other ozone-depleting compounds. Productions of halons ended in January 1994. On the other hand, in January 1996, U.S. production of many ozone-depleting substances virtually ended, including CFCs, carbon tetrachloride, and methyl chloroform.