In the 1980's, many concerns began about the depletion of the ozone layer. At that time, the most widely used refrigerants were the halomethanes R-12 (more common in automotive air conditioning and small refrigerators) and R-22 (used for residential and light commercial air conditioning, refrigerators, and freezers). Some early systems also used R-11. New production of R-12 stopped in the United States in 1995, and R-22 is to be phased out by 2020. The new substitute for R-22 is R-401A, and it is often marketed under the trade names of Puron, EcoFluor R410, Genetron R410A, and AZ-20. Please read below to learn more about R-410A.