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Questions and Answers on Alternative Refrigerants

These are commonly asked questions about substitute refrigerants. Lists are available in several formats. If you have questions beyond those in this fact sheet, please call the Stratospheric Ozone Protection Hotline toll-free at (800) 296-1996 or direct dial 202-343-9210 to leave inquiries.

You can also read more about EPA's Significant New Alternatives Policy (SNAP) Program, which evaluates alternatives for ozone-depleting substances. Finally, numerous fact sheets discuss motor vehicle air conditioning and substitutes for CFC-12 in this end-use.

General Questions

What refrigerants are used now? What is Freon?

"Freon" is a trade name for CFC and HCFC refrigerants sold by DuPont. Other trade names include Honeywell's "Genetron," Ineos Fluor's "Arcton," and Arkema's "Forane." Various companies sell the same CFCs, HCFCs, HFCs, and other products under different names. The most common ozone-depleting refrigerants are R-22, R-11, R-12, and R-123.

What alternative refrigerants are currently available? How do I know what I'm allowed to use?

Several new alternatives are on the market. The SNAP web site contains the latest list of acceptable substitutes by end-use. Another table lists the compositions of many blends, what they are intended to replace, their ASHRAE designations, and the generic names, if any, used when describing them in the Federal Register. The most common alternative refrigerants are R-404A, R-407C, and R-410A.

Who do I contact for information about substitutes?

Substitute refrigerants are made by many chemical manufacturers. Contact information, along with a listing of which refrigerants they make, is available from EPA's web site. A separate fact sheet is also available that lists manufacturers of motor vehicle air conditioning refrigerants.

What should I ask about new refrigerants?

EPA has a fact sheet titled "Ten Questions to Ask Before You Purchase An Alternative Refrigerant" that sums up the important points.

What are use conditions? Do I have to meet them?

In some cases, EPA believes that substitutes must be deemed unacceptable, unless the user meets specific conditions on how the substitute is used. Such substitutes will be listed as acceptable subject to use conditions. For example, EPA may require the use of a detector to warn users of leakage. Users must meet such conditions, or they will be in violation of the SNAP rule. Several use conditions are imposed on all automotive refrigerants, as explained in a fact sheet about motor vehicle air conditioning.

Will EPA recommend the best substitute for my equipment?

No, EPA only determines what substitutes are acceptable from an environmental and health perspective. EPA does not test refrigerants for their effectiveness as part of the SNAP process. EPA firmly believes that the market should determine which of the acceptable alternatives will work the best and gain the largest market share.

I don't see any substitutes listed for my equipment. How do I find out what's available?

The SNAP program has identified eight major industrial use sectors, and several end-uses within each sector. The SNAP rule only applies to those end-uses listed.

Are there any safety considerations for new refrigerants in chillers?

EPA believes that adherence to Standard 15 of the American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) will ensure the safety of technicians and building occupants. This standard applies to the use of all alternative refrigerants. In addition, systems designed and operated in accordance with ASHRAE Standard 3 will leak minimal amounts of refrigerant, thereby reducing ozone depletion and global warming impacts.

Is HCFC-123 safe to use in centrifugal chillers? Why is EPA listing it as acceptable?

Toxicity in general is a complex issue. The two types of toxicity, chronic and acute, pose completely different sets of hazards. Chronic toxicity relates to long-term exposures over a lifetime of experience with refrigeration equipment. Acute toxicity, in contrast, relates to the dangers posed by short-term exposure to very high concentrations of refrigerant, especially catastrophic releases.

Short-term exposure levels measure several types of risk. Cardiotoxicity indicates the concentration at which a worker's heart becomes sensitized to adrenalin; thus, in an emergency, exposure to this level may result in a heart attack. The asphyxiation level indicates when the amount of oxygen in the area is reduced to the point that a worker may become unconscious and therefore unable to escape.

All refrigerants pose each type of toxicity risk. HCFC-123 poses less acute risk than CFC-11, thus in the event of a major leak, you're safer with HCFC-123 than with CFC-11, which has been used extensively and safely for a long time.

As for chronic toxicity, it is true that some tests have shown that HCFC-123 caused tumors in several organs in rats, including the testes. However, the critical facts are that, in all cases: a) the tumors were benign, b) they only appeared after long exposures to very high concentrations, c) the tumors were never life-threatening, and d) the exposed rats actually lived longer at these higher concentrations.

The Acceptable Exposure Limit (AEL) set by the HCFC-123 manufacturers is 30 ppm. This represents the concentration to which a worker could be exposed 8 hours/day for a working lifetime without effects. In other words, the AEL is a chronic exposure limit. EPA conducted a study to determine the typical exposure level found in actual equipment rooms. The study concluded that if appropriate measures are taken (for instance, complying with ASHRAE 15), the concentration of HCFC-123 can be kept below 1 ppm.

EPA believes that HCFC-123 is a necessary and beneficial transitional refrigerant as the world phases out the CFCs, and SNAP lists it as acceptable for use in chillers.

Are flammable refrigerants automatically unacceptable?

EPA considers flammability as one factor in the SNAP risk screen. Rather than serving to disqualify a substitute, flammability may necessitate additional testing and assessment of risk. The risks from using a flammable refrigerant, such as a hydrocarbon, are extremely dependent on the conditions and type of equipment. EPA believes that it may well be possible to safely use flammable refrigerants, and encourages manufacturers to contact SNAP to discuss the information needed to support such a submission. To date, hydrocarbons have only been found acceptable in industrial process refrigeration. EPA is also currently reviewing four hydrocarbon refrigerants for use in household and commercial refrigerators and freezers.

It is illegal to use hydrocarbon refrigerants as CFC or HCFC substitutes in motor vehicle air conditioning. Furthermore, only a few hydrocarbon blends have been evaluated for other end uses, and those (HC-12a®, OZ-12a® and Duracool 12a) have been found unacceptable in all refrigeration and air conditioning end uses other than industrial process refrigeration. These refrigerants, as well as propane, butane, isobutane and propylene, have been found acceptable for industrial process refrigeration.

What are my choices for mobile air conditioning?

EPA has deemed several refrigerants acceptable for use in motor vehicle air conditioning, subject to several conditions on their use. In addition, several other fact sheets provide information about specific aspects of this type of system. CFC-12 may still be used as the refrigerant, but when a vehicle is retrofitted to use a new refrigerant, the conditions mentioned above apply.

Should companies be marketing their substitute refrigerant as a “drop-in”?

EPA finds the use of the term “drop-in replacement” as misleading when advertising refrigerants that substitute for an ODS refrigerant, such as HCFC-22, since the term confuses and obscures several important regulatory and technical points.

The agency is concerned technicians may incorrectly believe a “drop-in” can be added on top of the refrigerant already in the system. This practice would result in a new blend being used as a substitute to the original refrigerant. The resulting blend is not acceptable under the Significant New Alternatives Policy (SNAP) program.

Topping off with a different refrigerant could also decrease the effectiveness and longevity of the system. EPA encourages technicians to check with the refrigerant producer and equipment manufacturer for any guidance on using that refrigerant. Very often a new type of lubricant will be needed, certain parts such as elastomer gaskets will need to be replaced, and settings such as on TXVs will need adjustment.

In addition, when properly retrofitting a system, the old refrigerant must be removed consistent with Clean Air Act section 608 regulatory requirements before adding a different refrigerant. Persons opening the system must pull a vacuum as specified in 40 CFR 82.156 (see the 608 Fact Sheet for guidance). EPA also encourages technicians to repair leaks before re-charging with refrigerant.

What other alternative technologies are available?

Several other technologies are available as an alternative to classic vapor compression and absorption cycle equipment. Processes such as desiccant cooling, evaporative cooling, and other innovative solutions exist for various end uses. For example, evaporative cooling, which uses the evaporation of water to effect cooling, is currently available in systems designed to cool homes, office buildings, transit buses and more.

Questions from Manufacturers

When should I let EPA know I'm selling a new substitute?

You must notify EPA at least 90 days prior to sale of a new substitute. This time period allows SNAP staff to review the health and environmental implications of use of your alternative.

What information should I send EPA about a new substitute?

All data to be reviewed by EPA must be included in the SNAP submission. The details are listed on the SNAP application.

How are SNAP-reviewed refrigerants described in the SNAP updates?

Wherever possible, EPA will use ASHRAE designations for refrigerants. In cases when refrigerant compositions are confidential, EPA will use trade names. If it is not possible to list trade names in the Federal Register, a list will be available that connects generic names to trade names.


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