Hcfc123

chci2cf,

Commercial chillers

" From Kirsehner (1994); for a discussion of halon replacements, see Freemantle (1995). h HFC = hydrofluorocarbon; HCFC = hydrochlorofluorocarbon.

" From Kirsehner (1994); for a discussion of halon replacements, see Freemantle (1995). h HFC = hydrofluorocarbon; HCFC = hydrochlorofluorocarbon.

for hydrofluorocarbons, i.e., compounds containing hydrogen and fluorine but no chlorine. Because the HCFCs contain chlorine, they will continue to contribute to ozone depletion, and their ultimate phaseout is included in the Montreal Protocol and its amendments. However, the fraction that reaches the stratosphere is much smaller than for the CFCs because of their partial removal in the troposphere by reaction with OH.

For a discussion of the history of controls on ozone-depleting chemicals and factors that must be considered in finding transitional substitutes and long-term replacements, see Ko et al. (1994a), Parson and Greene (1995), the World Meteorological Organization Report (1995 and the 1999 update), and the volume edited by Miziolek and Tsang (1995).

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