R-22 is a widely used refrigerant in residential and light commercial air conditioning.
Chemically, it is known as dichloro difluoro methane, with the formula CHClF$_2$.
It is classified as a hydrochlorofluorocarbon (HCFC).
R-22 was introduced as a replacement for older CFCs due to its reduced ozone depletion potential, but its use is currently being phased out globally.
Note that monochloro difluoro methane is R-12, and other compounds like tetrachloro difluoro ethane and trichloro monofluoro methane are distinct CFCs.
Thus, dichloro difluoro methane is the accurate chemical identifier for R-22.