Ozone (O3), the key substance of the protective ozone layer, is naturally created and destroyed by chemical reactions in the stratosphere. When chlorine is present in the stratosphere, it upsets the natural ozone layer balance by destroying O3 faster than it is naturally replaced. It is the chlorine present in CFCs (Chlorofluorocarbons) and HCFCs (Hydrochlorofluorocarbons) that causes ozone depletion.
In order to reduce and eliminate ozone depletion, the Montreal Protocol required production and importation of CFCs in Canada and other developed countries to be halted at the end of 1995. Under this protocol, Canada has started phasing out the production and importation of HCFCs. This is of particular importance to the refrigeration and air conditioning industry because refrigerant R-22, commonly used in residential and commercial applications, is an HCFC.
The industry worldwide has developed a wide variety of long term refrigerant alternatives that are classified as HFCs (Hydrofluorocarbons). HFCs are now available for most refrigeration and air conditioning applications. In the area of unitary air conditioning, the industry manufacturers have primarily moved towards HFC-410A as the replacement for R-22 in NEW equipment. The characteristics of R-410A are considerably different than that of R-22, and while no specific R-410A training is mandated, technicians should be knowledgeable and have the proper tools to safely handle this refrigerant.