Methyl chloroform: impact on stratospheric ozone.

Regulations to limit the use of trichloroethylene as a degreasing solvent have led to an increased use of the more photochemically inert solvent methyl chloroform as a substitute. Model calculations show that about 15 percent of the methyl chloroform released into the atmosphere will reach the stratosphere. Time scenarios based on past production figures and reasonable projections for future release rates lead to a steady-state ozone depletion due to this solvent about 20 percent as large as those resulting from the continuous release of chlorofluoromethanes at 1973 rates.