ABSTRACT
1,1-Difluoroethane may be released to the environment as emissions during its use as a refrigerant and it may be released to the soil from the disposal of refrigeration units containing this compound. If released to the soil, 1,1-difluoroethane may rapidly volatilize from soil surfaces to the atmosphere or leach through soil possibly into ground water. If released to water, volatilization would be the dominant fate process based on a half-life of 2.4 hours from a model river. If released to the atmosphere, 1,1-difluoroethane is expected to exist exclusively in the vapor phase. In the troposphere, 1,1-difluoroethane reacts slowly with photochemically generated hydroxyl radicals (half-life of 472 days). This relatively slow half-life in the lower atmosphere suggests that some 1,1-difluoroethane may gradually diffuse into the stratosphere. In the stratosphere, 1,1-difluoroethane is expected to slowly photolyze and contribute to the removal of stratospheric ozone.
