CFC-11

Trends

Significant production of CFC-11 began in the late 1930s for use in refrigeration. Production (and release) increased very slowly until after World War II, when CFCs began to be used as propellants for aerosol sprays. By the 1950s, the use of CFC-11 as the blowing agent in open-cell (foam rubber) and closed-cell (rigid polyurethane) foams constituted an additional significant source of release. During the 1960s and early 1970s, production and release of CFC-11 grew very rapidly. Over the 10-year period 1964-74, for example, total CFC-11 release grew exponentially, increasing at an average rate of 13.0% per year, primarily because of the rapid worldwide expansion of CFC use in aerosols. In 1975, however, fluorocarbon production and release began to decline after the U.S. ban on CFCs in aerosols. By the early 1980s, however, this decline reversed, partly because of growth in aerosol production in countries not participating in the ban. In addition, the use of CFC-11 as the blowing agent in rigid polyurethane foams grew unabatedly throughout the 1970s and 1980s. For the period 1974-89, CFC-11 release from this end use grew exponentially, increasing at an average rate of 9.8% per year. By 1992, however, release from closed-cell foam appeared to begin leveling off. Nevertheless, as other end uses of CFC-11 declined precipitously, release from closed-cell foams in 1992 constituted >60% of the total release worldwide. The recent decline in the release of CFC-11 from all sources (primarily aerosols) has occurred largely in response to efforts to limit emissions of fully halogenated CFCs as prescribed by the 1987 Montreal Protocol and its subsequent revisions.

CFC 11 AFEAS Releases Graph

• CFC-11 releases, 1938-92