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Questions and Answers about R-22a 

1.  What is R-22a?

R-22a, also known as 22a Refrigerant, is a highly flammable colorless gas, heavier than air.  The product’s Material Data Safety Sheet (MSDS) states that it is composed of “liquefied petroleum gas.” Its contents have been identified as propane; in some cases, it may also contain small amounts of other hydrocarbons or a pine-scented odorant.  

2.  What are the potential safety risks of R-22a?

If enough R-22a is concentrated in one space, and the refrigerant comes in contact with an ignition source, it could burn or even explode.  

3.  Has EPA determined whether R-22a can be used safely as a refrigerant in air conditioning equipment designed for use with HCFC-22?

No. R-22a has not been submitted to EPA for review for use as a refrigerant in existing air conditioning equipment designed for use with HCFC-22 (R-22), and EPA has not approved R-22a for use in such equipment. R-22 is an ozone-depleting refrigerant which has been widely used in home air conditioning systems and its supply is now being phased out in response to the Montreal Protocol. EPA reviews health, safety and environmental impacts of refrigerants through its Significant New Alternatives Policy (SNAP) program, EPA's program to evaluate and regulate substitutes for the ozone-depleting chemicals that are being phased out under the stratospheric ozone protection provisions of the Clean Air Act (CAA). In Section 612(c) of the CAA, the Agency is authorized to identify and publish lists of acceptable and unacceptable substitutes.  

4.  Is it legal to sell R-22a for use as a refrigerant in air conditioning equipment designed for use with HCFC-22?

No. The CAA and EPA’s regulations prohibit the introduction into interstate commerce of substitutes that have not been submitted to EPA for review and listing under 40 CFR 82.176(a).  

EPA issued this press release, EPA Warning: Recharging Air Conditioners with Wrong Refrigerant Poses Injury and Fire Risks (July 22, 2014)

5.      If R-22a is not legal for use as a refrigerant in air conditioning equipment designed for use with HCFC-22 (see Q&A 4), what is EPA doing about it?

EPA cannot comment on any specific enforcement actions that it may be undertaking or that are in the early stages of investigation. We are looking into allegations of illegal activity regarding the sale of R-22a as a refrigerant and will take enforcement actions where appropriate. Here are examples of enforcement actions that EPA has taken.

6.  Are there other flammable hydrocarbons or blends that EPA has determined can be used safely in air conditioning equipment designed for use with HCFC-22?

No. EPA has not found acceptable any flammable hydrocarbon refrigerants for use in existing air conditioning systems designed for use with HCFC-22. Use of flammables as a retrofit in equipment that was designed for nonflammable materials presents risks to consumers, to the equipment, and to service technicians who may not be prepared for handling flammable refrigerants. Further, EPA is aware that in some cases, use of flammable refrigerants to replace materials used by the manufacturer in the equipment’s original charge will void the warranty. Additional Information:  EPA has prohibited the use of the following hydrocarbon refrigerants in air conditioning systems: Hydrocarbon Blend A (sold under the name OZ-12) and Hydrocarbon Blend B (sold under the names DURACOOL 12a and HC-12a). In addition, EPA is aware that a number of refrigerants with “22a” or “R-22a” in the name contain flammable hydrocarbons and are being sold for use in air conditioning systems, but they have never been submitted to EPA for the required health, safety and environmental review and are therefore not approved for use in air conditioning systems.  

7.  Which refrigerants are allowed to be used in air conditioning systems for air conditioning equipment designed for use with HCFC-22?

You can find EPA’s lists of acceptable refrigerants for different uses here. The list of acceptable refrigerants for use in home air conditioning is at this link: “Acceptable Substitutes in Household and Light Commercial Air Conditioning.”

8.      Are there other flammable hydrocarbons or blends that EPA has found can be used safely as refrigerants in refrigeration and air conditioning, other than in air conditioning equipment designed for use with HCFC-22?

EPA has not listed any flammable hydrocarbons1 as acceptable substitutes for use in air conditioning equipment to date; however, EPA has listed a number of flammable hydrocarbon refrigerants as acceptable substitutes for specific refrigeration uses, including:

EPA notes that the listings for household and commercial refrigerators and freezers apply only to equipment that was specifically designed to be used with that refrigerant. The Agency has not found hydrocarbon refrigerants acceptable for use in refrigerators that were originally made for a different, non-flammable refrigerant.

These determinations were based on detailed assessments of the risks posed by each flammable refrigerant in the particular application or type of equipment to be used. In addition, EPA’s regulations adopt the results of safety reviews by industry standards setting bodies as mandatory use conditions. So, our rules further reduce risk by setting requirements for the amount of refrigerant used, design and testing of equipment, and warning labels, among other things. Generally speaking, flammable refrigerants can be safely used where equipment has been specifically designed to operate safely using them. Use of flammables as a retrofit in equipment that was designed for nonflammable materials presents risks to consumers, to the equipment, and to service technicians who may not be prepared for handling flammable refrigerants.  

EPA issued this press release, “EPA Warns Against Use of Refrigerant Substitutes That Pose Fire and Explosion Risk” (July 1, 2013).


1. EPA has reviewed and found acceptable some refrigerant blends that contain more than 95% non-flammable compounds and less than 5% hydrocarbons.


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