Significant New Alternatives Policy (SNAP)

Acceptable Substitutes in Non-Mechanical Heat Transfer Systems

You will need Adobe Reader to view some of the files on this page. See EPA’s About PDF page to learn more.Substitutes are reviewed on the basis of environmental and health risks, including factors such as ozone depletion potential, global warming potential, toxicity, flammability, and exposure potential. Lists of acceptableHelpacceptableThis designation means that a substitute may be used, without restriction, to replace the relevant ODS within the end-use specified. For example, HCFC-22 is an acceptable substitute for R-502 in industrial process refrigeration. Note that all SNAP determinations apply to the use of a specific product as a substitute for a specific ODS in a specific end-use. and unacceptableHelpUnacceptableThis designation means that it is illegal to use a product as a substitute for an ODS in a specific end-use. For example, HCFC-141b is an unacceptable substitute for CFC-11 in building chillers. Note that all SNAP determinations apply to the use of a specific product as a substitute for a specific ODS in a specific end-use. substitutes are updated several times each year. The list of acceptable substitutes are shown below.

Note: SNAP-related information published in the Federal Register takes precedence over all information on this page.

Substitute Trade Name Retrofit/New ODPHelpODPA number that refers to the amount of ozone depletion caused by a substance. The ODP is the ratio of the impact on ozone of a chemical compared to the impact of a similar mass of CFC-11. Thus, the ODP of CFC-11 is defined to be 1.0. Other CFCs and HCFCs have ODPs that range from 0.01 to 1.0. The halons have ODPs ranging up to 10. Carbon tetrachloride has an ODP of 1.2, and methyl chloroform's ODP is 0.11. HFCs have zero ODP because they do not contain chlorine. A table of all ozone-depleting substances ( shows their ODPs, GWPs, and CAS numbers. GWPHelpGWPThe index used to translate the level of emissions of various gases into a common measure in order to compare the relative radiative forcing of different gases without directly calculating the changes in atmospheric concentrations. GWPs are calculated as the ratio of the radiative forcing that would result from the emissions of one kilogram of a greenhouse gas to that from the emission of one kilogram of carbon dioxide over a period of time (usually 100 years). Gases involved in complex atmospheric chemical processes have not been assigned GWPs. See lifetime. ASHRAEHelpASHRAEASHRAE is an international organization that establishes standards for the uniform testing and rating of heating, ventilation, air conditioning, and refrigeration equipment. It also conducts related research, disseminates publications, and provides continuing education to its members.
SNAP Listing Date Use Conditions
C6 Perfluoroketone Novec™ 649 R/N 0 0.6 - 1.8 A1 September 30, 2009;
June 16, 2010
C7 Fluoroketone Novec™ 774 R/N 0 1 A1 August 10, 2012  
Galden Fluids   R 0 N/A A1 February 24, 1998  
HFC-236fa   R/N 0 9,810 A1 June 8, 1999 When manufactured using any process that does not convert perfluoroisobutylene (PFIB) directly to HFC-236fa in a single step.
HFC-245fa Genetron® 245fa R/N 0 1,030 A1 March 29, 2006;
June 16, 2010
HFC-4310mee   R/N 0 1,640 A1 June 19, 2000  
HFE-7000   R/N 0 575 A1 March 22, 2002;
June 16, 2010
HFE-7100   R/N 0 297 A1 June 8, 1999;
June 16, 2010
Only acceptable for use as a secondary heat transfer fluid in not-in-kind systems.
HFE-7200   R/N 0 59 N/A December 18, 2000;
June 16, 2010
Only acceptable for use as a secondary heat transfer fluid in not-in-kind systems.
HFO-1234ze Solstice 1234ze R/N 0 6 A2L June 16, 2010  
HFO-1336mzz(Z) ((Z)-1,1,1,4,4,4-hexafluorobut-2-ene) Opteon® MZ N 0 9 A1 May 23, 2016  
Methoxytridecafluoroheptene isomers MPHE; Sinera™ R/N 0 2.5 A1 July 16, 2015  
Mineral Oil   R/N 0 0 N/A July 28, 1995  
PFCs (C3F8, C4F10, C5F12, C5F11NO, C6F14, C6F13NO, C7F16, C7F15NO, C8F18, C8F17NO, C9F21N)   R/N 0 N/A N/A N/A PFCs are only allowed in new systems where a study has demonstrated that no other alternatives are technically feasible due to safety or performance requirements; this study must be kept available for review.
R-125/R-290/R-134a/R-600a (55.0/1.0/42.5/1.5) ICOR AT-22 R/N 0 2,530 A1 March 29, 2006  
R-170 (Ethane)   N 0 5.5 A3 April 10, 2015 Detailed conditions apply - see Rule
R-404A HP-62 R/N 0 3,920 A1 December 20, 2002  
R-407C Suva 407C, Klea 407C R/N 0 1,770 A1 December 20, 2002;
August 21, 2003
R-410A AZ-20, Suva 9100, Puron N 0 2,090 A1 December 20, 2002  
R-417A ISCEON 59, NU-22 R/N 0 2,350 A1 December 6, 1999;
June 16, 2010
R-422B ICOR XAC1, NU-22B R/N 0 2,530 A1 March 29, 2006  
R-422C ICOR XLT1 R/N 0 3,390 A1 March 29, 2006  
R-422D ISCEON MO29 R/N 0 2,730 A1 September 28, 2006  
R-437A KDD6, ISCEON MO49 Plus R/N 0 1,810 A1 January 2, 2009  
R-438A KDD5, ISCEON MO99 R/N 0 2,270 A1 October 4, 2007;
June 16, 2010
R-507, R-507A AZ-50 R/N 0 3,990 A1 December 20, 2002  
R-744 (Carbon Dioxide, CO2)   R/N 0 1 A1 January 13, 1995;
June 16, 2010
Trans-1-chloro-3,3,3-trifluoroprop-1-ene Solstice 1233zd(E), Solstice N12 Refrigerant N 0.00024 - 0.00034 4.7 - 7 A1 October 21, 2014  
Volatile Methyl Siloxanes   R/N 0 <20 N/A July 28, 1995;
June 16, 2010
Water   R/N 0 N/A A1 July 28, 1995;
June 16, 2010

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