A 1987 international environmental agreement called the Montreal Protocol established requirements that began the worldwide phaseout of ozone-depleting CFCs (chlorofluorocarbons). It was modified in 1992 to establish a phaseout schedule for HCFCs (hydrochlorofluorocarbons). While HCFCs are less damaging to the ozone layer than CFCs, they still contain chlorine that destroys the ozone. The United States EPA implements the amended Montreal Protocol via the Clean Air Act.

By January 1, 2015, the USA is required to reduce its HCFC consumption by 90% below its baseline. By January 1, 2020, the USA will need to reduce its HCFC consumption by 95% below baseline.

While chemical manufacturers will not be allowed to produce new R-22; recovered, recycled and reclaimed refrigerant will be allowed past 2020 to service existing systems. This should allow enough R-22 to supply existing air conditioning systems.

HCFC-22, which is also known as R-22, has been the main refrigerant used for residential heat pump and air-conditioning systems for more than four decades. Leakage of a greenhouse gas such as R-22 contributes to ozone depletion. As the current R-22 manufacturing is phased out, manufacturers of residential air conditioning systems are now offering equipment that uses ozone-friendly refrigerants. With these significant changes in refrigerant and new systems, the testing and training of technicians becomes a high priority. The consumer should make sure he uses a company that uses EPA-certified technicians.