Chlorofluoromethane or Freon 31 is the hydrochlorofluorocarbon (HCFC) with the formula CH<sub>2</sub>ClF. It is a colorless, odorless, flammable gas. It is a class II ozone depleting substance and in accordance with the Montreal protocol, its production and import were banned on 1 January 2015.
Pyrolysis of a mixture of dichlorofluoromethane and chlorofluoromethane gives hexafluorobenzene:
It was used as a refrigerant and has an ozone depletion potential of 0.02.
Its crystal structure is monoclinic with space group P2<sub>1</sub> and lattice constants a = 6.7676, b = 4.1477, c = 5.0206 (0.10<sup>âÂÂ1</sup> nm), ò = 108.205ð.
At an altitude of 22 km, traces of chlorofluoromethane occur (148 ppt).