Today the EPA issued a warning against using cheap and also flammable substitues for R-22, which is the refrigerant used in most older (even a few years old) home air conditioning systems. There have been reports of injuries due to the fact that some of these replacements contain propane! The EPA has not approved any such materials for use in home AC systems so please be careful. Environmental Doctor has been using the new refrigerant, R-410A, which replaced the R-22 in manufacturing about 2 years ago, for well over 10 years. We are also providing service to the older R-22 systems still in operation using only approved, direct replacement refrigerant (R-22).