Dichlorofluoromethane or Freon 21 or R 21 is a halomethane or hydrochlorofluorocarbon with the formula CHCl2F.

It is produced by fluorination of chloroform using a catalyst such as antimony trifluoride:[4] Dichlorofluoromethane was used as a propellant and refrigerant.

Due to its role in ozone depletion, dichlorofluoromethane has been largely phased out.

Production and consumption has been since 2004 reduced to 15% of level from 1989 and it is to be phased out in 2015 according to Montreal Protocol.

Pyrolysis of a mixture of dichlorofluoromethane and chlorofluoromethane gives hexafluorobenzene:[4] Its critical point is at 178.5 °C (451.7 K) and 5.17 MPa (51.7 bar).