Manufacturers have commercialized more than 50 new refrigerants (including blends) in the last decade, and they are examining additional candidates. Users should expect a number of new introductions as the phaseout approaches for R-22, which now is the most widely used refrigerant. A similar flurry of service fluids occurred with the phaseout of R-12 and R-502; R-12 was the most widely used refrigerant until a few years ago.
This article provides two tables that summarize selected physical, safety, and environmental data for the old and current refrigerants and for leading replacement candidates. The data in the two tables are the same, but are presented in different manners.