R22 is a hydrochloroflurocarbon (HCFC) which was commonly used in air conditioning systems. When R22 is released into the air, the ultraviolet rays of the sun cause it to decompose and chlorine is released in the stratosphere. Chlorine reacts with ozone, reducing the amount of the ozone. Due to the ozone layer depletion, harmful ultraviolet rays reach the surface of the earth giving rise to a number of health and environment issues. The international community therefore signed the Montreal Protocol to phase out ozone depletion materials by 2030. The European union however, have imposed a ban from 1st January 2015.
The use of virgin R22 refrigerant has been banned since December 31, 2009 (under EU Ozone regulation EC2037/2000)