EPA, the Consumer Product Safety Commission, and the U.S. Food and Drug Administration ban the use of CFCs as propellants in aerosol spray cans; however, CFCs can continue to be used in aerosol sprays as solvents and as active ingredients.

The U.S. and 22 other countries sign the Montreal Protocol on Substances that Deplete the Ozone Layer, committing to reducing production and importing of certain CFCs to 50 percent of 1986 levels by 1998 and freezing of halon production at 1986 levels in 1992.

The U.S. honors its commitment to the Protocol when EPA issues final rules cutting domestic production and importing by 50 percent, through a system of tradable allowances.

Congress levies excise tax on sale of CFCs and other ozone depleters. This program is handled by the Internal Revenue Service.

In London, Parties to the Montreal Protocol pass amendments calling for total phaseout of production and importation of CFCs by 2000.

Clean Air Act Amendments of 1990 signed, and include phaseout controls similar to London Amendments, although interim phaseout timetable more stringent. CFCs, halons and carbon tetrachloride must be phased out by 2000; methyl chloroform by 2002; and hydrochlorofluorocarbons (HCFCs) by 2030. Statute also requires rules restricting use of ozone-depleting substances in society, through such means as recycling and reducing emissions to the atmosphere.

EPA proposes rule implementing Clean Air Act production and importing phaseout schedule for CFCs, halons, carbon tetrachloride and methyl chloroform.

EPA issues final rule for mandatory recycling of CFCs in motor vehicle air conditioners.

The Parties to the Montreal Protocol meet in Copenhagen and agree to accelerate the phaseout of CFCs, carbon tetrachloride and methyl chloroform to Jan. 1, 1996, and halons to Jan. 1, 1994. (By April 1993, 107 nations were party to the Protocol).

EPA issues final rule banning use of ozone depleters in certain nonessential products, such as aerosol spray cans.

EPA issues final rule requiring warning labels on products containing or manufactured with CFCs and other ozone depleters.

EPA proposes rule to accelerate the phaseout of halons to Jan. 1, 1994, CFCs, methyl chloroform and carbon tetrachloride to Jan. 1, 1996, some forms of HCFCs to 2003; also adds methyl bromide and hydrobromofluorocarbons (HBFCs) to list of ozone-depleting substances, the former due for phaseout Jan. 1, 2000, and latter due by Jan. 1, 1996.

EPA proposes rule requiring federal agencies to change contracting practices to minimize purchases of goods containing ozone depleters and to maximize use of safe alternatives.

EPA proposes safe substitutes rule listing acceptable and unacceptable alternatives to ozone depleters, and lays out procedure for future listings.

EPA issues final rule prohibiting venting of ozone depleters into atmosphere during servicing and disposal of residential and commercial air conditioners and refrigerators.