The Montreal Protocol was signed in 1987 by members of the United Nations to phase out and reduce production of CFCs and other ozone-damaging chemicals by 50 percent by 1998. Amendments and revisions to the Montreal Protocol were made in 1990, 1992, and 1997 to include other chemicals and accelerate the phase-out of certain chemicals. Production of CFCs, carbon tetrachloride, and methyl chlororform was phased out by 1996 in the United States and other highly developed countries.