R-4106A Reaches a Key EPA SNAP Milestone for New Equipment
FluoroFusion is pleased to share that the U.S. Environmental Protection Agency (EPA) has found our Significant New Alternatives Policy (SNAP) submission for R-4106A complete as of September 15, 2026, for use in new equipment. In a letter dated September 24, 2026, the EPA stated that R-4106A "may be sold and imported in the United States" for the listed refrigeration and air conditioning end-uses, pending the Agency's final decision in a notice or rule published in the Federal Register.
This is an important step for R-4106A and for equipment manufacturers who are looking for more options as the industry continues its move to lower-GWP refrigerants.
What the EPA Completeness Determination Covers
EPA's SNAP program evaluates substitutes for ozone-depleting substances under section 612 of the Clean Air Act. As EPA notes in its letter, a completeness determination is not the same as a determination that the substitute is acceptable.
The September 24 completeness determination applies to new equipment only in the following end-uses:
Chillers (commercial comfort air conditioning), positive displacement chillers
Residential and light commercial air conditioning and heat pumps, all applications
EPA's final determination on whether R-4106A is acceptable will be published in the Federal Register. Use of R-4106A in retrofit (existing) equipment is a separate matter and is not covered by this completeness determination. We will share updates as that process moves forward.
About R-4106A
R-4106A is a four-component blend of R-32, R-1234ze(E), R-125, and R-744 (carbon dioxide), developed as an alternative to R-454B for new residential and light commercial air conditioning and heat pump designs.
GWP Within Technology Transitions Limits
R-4106A has a GWP of 681 (100-year, calculated per the EPA methodology in 40 CFR 84.64). That falls below the 700 GWP limit that applies to new residential and light commercial AC and heat pump systems and new comfort cooling chillers under EPA's Technology Transitions rule.
Modeled Performance
In a thermodynamic cycle analysis across nine air conditioning and heat pump operating conditions, R-4106A showed:
Volumetric cooling capacity 5.0% to 8.5% higher than R-454B (6.6% average)
Coefficient of performance (COP) 1.4% to 3.9% higher than R-454B (2.7% average)
A negligible change in pressure ratio compared to R-454B
Low temperature glide
These results were presented in our paper at the 21st International Refrigeration and Air Conditioning Conference at Purdue in July 2026. As with any new refrigerant, performance in a specific system should be confirmed through the manufacturer's own testing.
Safety Classification
R-4106A has an ASHRAE Standard 34 safety classification of A2L. For transportation, it ships as UN1078, Refrigerant gases, n.o.s., and is classified under U.S. Department of Transportation criteria as a Division 2.2 non-flammable gas based on flammability test data evaluated under 49 CFR 173.115.
The same test data place R-4106A outside the flammable gas definition in the International Fire Code and International Building Code, which use the same 13 percent and 12 percentage point thresholds as DOT. Where those codes are adopted, the maximum allowable quantity limits for flammable gases do not apply to stored R-4106A cylinders, which can allow distributors, contractors, and manufacturers to keep more product on hand in a given space. Storage requirements depend on the code edition your jurisdiction has adopted and on your local fire official, so confirm requirements with your authority having jurisdiction.
Equipment designed for R-4106A must meet all applicable requirements for A2L refrigerants, including UL 60335-2-40 and ASHRAE Standard 15, along with any use conditions EPA sets in its final action.
Built to Use Reclaimed Refrigerant
R-4106A's manufacturing process is designed to use reclaimed HFC components as feedstock, giving previously produced refrigerant a second life and supporting the reclamation goals of the AIM Act. As with all HFC and HFO refrigerants, R-4106A must be recovered during service and at end of life and must never be vented.
What This Means for OEMs
Manufacturers developing new residential and light commercial AC, heat pump, and comfort cooling chiller equipment can now begin working with R-4106A. Our technical team can support your evaluation with property data and performance modeling, and can discuss sample availability.
EPA's September 24 letter and the R-4106A field brief are available at fluorofusion.com/4106a. To learn more or request technical information, contact us at info@fluorofusion.com or 919-800-0277.
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