An international agreement reached in 1987 to reduce the production and consumption of chlorofluorocarbons (CFCs) and halon, substances which deplete the ozone layer in the upper atmosphere. This was amended in 1990 to target the phasing out of CFCs and halon by 2000. The agreement also provides for trade bans on CFCs and CFC-using products. CFCs and halon are inert and non-toxic substances, and were widely used in refrigeration, foams, aerosols, and dry-cleaning, and halon in fire extinguishers. It has become possible to replace these by less ozone-destructive products.