Quick Detail:
R22,named Chlorodifluoromethane or difluoromonochloromethane is a hydrochlorofluorocarbon (HCFC).  It is commonly used as a propellant and refrigerant. 
 
Description:
 
The applications of R22 are being phased out in developed countries due to the compound's ozone depletion potential (ODP) and high global warming potential (GWP), although global use of R-22 continues to increase because of high demand in developing countries. R-22 is a versatile intermediate in industrial organofluorine chemistry, e.g. as a precursor to tetrafluoroethylene. R-22 cylinders are colored light green.
UN Code                  1018
CAS Code                        75-45-6
 
 
Application:
 
R-22 is often used as an alternative to the highly ozone-depleting CFC-11 and CFC-12, because of its relatively low ozone depletion potential of 0.055,among the lowest for chlorine-containing haloalkanes. However, even this lower ozone depletion potential is no longer considered acceptable.

As an additional environmental concern, R-22 is a powerful greenhouse gas with a global warming potential that is 1810 (which indicates 1810 times as powerful as carbon dioxide).[4] Hydrofluorocarbons (HFCs) are often substituted for R-22 because of their lower Ozone Depleting Potential, but these refrigerants also have high global warming potential. R-410A, for example, is often substituted, but has a Global Warming Potential of 1725. Another substitute is R404A with a Global Warming Potential of 3900. Other substitute refrigerants are available with low Global Warming Potential. Ammonia (R717), for example, has a Global Warming Potential of <1 and is a popular substitute on fishing vessels. Propane (R-290), is another example, and has a Global Warming Potential of 3, although it is rarely used in refrigeration systems because of its flammability and potential for explosion.