Recently, the U.S. Environmental Protection Agency (EPA) issued a warning to consumers, technicians, and contractors about the safety hazards associated with propane-based refrigerants used to charge home air conditioning systems. R-22a (also known as HCFC-22) is a highly flammable refrigerant that contains propane, small amounts of other hydrocarbons, and a substance that gives off a pine-scented odorant.
R-22a has been the refrigerant of choice for residential air conditioners and heat pumps for almost a half century. The use of R-22a has been phased out, however, under the Montreal Protocol, an environmental treaty ratified to eliminate the use of ozone depleting substances. Leaks in A/C systems using R-22a contribute greatly to ozone depletion. Another reason the refrigerant is no longer encouraged for use is because enough R-22a concentrated in one space coming in contact with an ignition source can lead to an explosion.
The EPA is currently investigating cases where these refrigerants are being marketed to consumers seeking to recharge existing home air conditioning systems that weren’t designed to use propane. As they have never been submitted to the agency for review of their health impacts, they are not approved for existing air conditioning systems and pose a serious injury risk to both consumers and technicians.
Homeowners and technicians are strongly encouraged to limit use of propane or other hydrocarbon refrigerants to only those appliances specifically designed for such use. The EPA has approved the use of propane as a substitute refrigerant for R-22a only in industrial process refrigeration systems and freezers that are specifically designed to use flammable hydrocarbon refrigerants.
Remember—if you have propane in your air conditioning system and a part has to be replaced or repaired, welding any portion of it without first removing the propane could result in an explosion that can cause fatal injuries. Make sure it is properly marked to alert technicians that the equipment contains a flammable substance.