After GWP: Why TFA Is the Next Number Worth Knowing
For most of the past decade, refrigerant selection has revolved around one number: global warming potential. The AIM Act step-down and EPA’s Technology Transitions rules made GWP the threshold every new system has to clear. More recently, PFAS has entered the conversation, and with it a broader question: what happens to a refrigerant after it leaves the system?
That question leads to trifluoroacetic acid, or TFA. It is not yet a selection criterion the way GWP is, but regulators are starting to measure it, and today’s refrigerants differ widely in how much of it they can produce.
What TFA Is and Where It Comes From
TFA is a small, highly persistent organofluorine compound that dissolves readily in water. It does not meaningfully break down in the environment, so once it forms, it stays, showing up in rain, surface water and groundwater.
Refrigerants are one of several sources. A released refrigerant eventually breaks down in the atmosphere, and depending on its molecular structure, some of that breakdown ends as TFA. The share that does is called the TFA yield, and it varies enormously from one molecule to the next:
Refrigerant component | Estimated TFA molar yield |
R-1234yf | About 100% |
R-227ea | About 100% |
R-134a | About 7% to 21% |
R-1234ze(E) | Non-detect to about 2%, depending on climate |
R-125 | Low |
For some molecules the yield also depends on where the breakdown happens. R-1234ze(E) breaks down into an intermediate compound that can either form TFA or be destroyed by sunlight. Destruction by sunlight dominates at northern-temperate latitudes, including much of the United States, so R-1234ze(E)’s TFA yield there is expected to sit at the low end of its range.
The takeaway is that TFA potential is a property of the components in a refrigerant, not of a refrigerant class. Two refrigerants with similar GWPs and the same ASHRAE safety classification can differ in TFA potential by well over an order of magnitude.
Why TFA Is Getting Attention Now
Three developments in 2026 moved TFA from an academic topic to a regulatory one:
Europe: On June 5, 2026, the European Chemicals Agency’s Committee for Risk Assessment adopted an opinion recommending TFA be classified as toxic to reproduction (Category 1B), persistent, mobile and toxic (PMT), and very persistent and very mobile (vPvM). The European Commission will now consider whether to amend the EU’s classification regulation accordingly.
United States: On July 1, 2026, EPA proposed the Sixth Unregulated Contaminant Monitoring Rule, which includes TFA among the contaminants public water systems would sample for between 2028 and 2030.
Definitions: TFA counts as a PFAS under the broad OECD definition, but falls outside the working definition EPA uses in its National PFAS Testing Strategy. Depending on whose definition you use, TFA is either part of the PFAS conversation or right beside it. Either way, it is on the radar.
High-TFA Refrigerants and a Lower-TFA Alternative
R-454B is a good example of how a low-GWP refrigerant can still carry significant TFA potential. It is a blend of 68.9% R-32 and 31.1% R-1234yf. R-32 has no pathway to TFA, but R-1234yf converts almost entirely.
R-4106A was formulated differently. It is a four-component blend:
Difluoromethane (R-32): 72.8%
Trans-1,3,3,3-tetrafluoroprop-1-ene (R-1234ze(E)): 19.8%
Pentafluoroethane (R-125): 5.4%
Carbon dioxide (R-744): 2.0%
R-32 and R-744 have no pathway to TFA, R-125 has a low yield, and R-1234ze(E) ranges from non-detect to about 2%. R-4106A has a GWP of 681 and an ASHRAE A2L safety classification.
Refrigerant | Main TFA-forming component | Estimated TFA per kg released |
R-454B | R-1234yf | About 310 g |
R-4106A | R-1234ze(E) | 0 to about 4 g |
Estimates are FluoroFusion calculations based on blend composition and the published yields cited below. Ranges reflect the climate-dependent yield of R-1234ze(E). Published yields carry real uncertainty, so these figures are best read as a comparison, not a measurement.
EPA found our SNAP submission for R-4106A complete as of September 15, 2026, for use in new equipment. In its completeness determination, EPA stated that R-4106A “may be sold and imported in the United States” for new residential and light commercial air conditioning and heat pumps and new positive displacement chillers for commercial comfort cooling, pending EPA’s final decision, which can only be made in a notice or rule published in the Federal Register. In those end-uses, R-4106A offers a lower-TFA alternative to R-454B. Existing equipment is a separate matter, not covered by this completeness determination.
Data Center Cooling: A Problem Not Yet Solved
Data center cooling has its own Technology Transitions subsector, with a 700 GWP limit taking effect January 1, 2027, for both manufacture or import and installation, according to EPA’s HFC restrictions by sector. Refrigerant decisions for this segment are being made now.
Several refrigerants used in data center cooling carry meaningful TFA potential:
Refrigerant | Main TFA-forming component(s) | Estimated TFA per kg released |
R-513A | R-1234yf (44%), R-134a (56%) | About 500 g |
R-454B | R-1234yf (31.1%) | About 310 g |
R-515B | R-227ea (8.9%), R-1234ze(E) (91.1%) | About 60 to 80 g |
R-1234ze(E) | R-1234ze(E) | 0 to about 20 g |
Estimated using the same method as the table above.
The industry has done substantial work to bring GWP down in this segment. TFA has not yet been a consistent part of that conversation. As monitoring and classification move forward, it may well become one more factor in refrigerant selection for data centers and other fast-growing segments.
Who Owns the Molecule’s Lifecycle?
A pound of refrigerant passes through a lot of hands. It is formulated, manufactured, blended and packaged. It is charged into equipment, distributed, installed and serviced. Eventually it is recovered and reclaimed, or it leaks.
If TFA becomes a regulated concern, the question of who answers for it is wide open. It could fall on whoever chose the chemistry and produced it, the companies that blend and package it, the manufacturers that select it for their equipment, the distributors that move it, the contractors and technicians who handle it in the field, the owners and operators of the equipment, the reclaimers that return it to service, or some combination. Regulators have not answered that question, and no one should assume they know where it will land.
What already exists is a shared system of responsibility for the refrigerant itself. Technicians are certified under Section 608 of the Clean Air Act. Since January 1, 2026, owners and operators of appliances with a full charge of 15 lb or more of an HFC with a GWP above 53 have leak repair obligations under 40 CFR Part 84 Subpart C. Reclaimers are certified under 40 CFR 82.164 and appear on EPA’s public list of certified reclaimers.
Whoever ultimately carries the responsibility, the most reliable way to keep TFA out of the environment is the same: keep refrigerant in the system, and recover it at service and at end of life. In EPA’s words, “Maximizing reclamation and minimizing releases of HFCs from equipment supports the domestic phasedown of HFCs.”
FluoroFusion’s part of that loop is reclamation. We blend and package refrigerant for the service market, hold HFC consumption allowances, and operate as an EPA-certified reclaimer, with a network of collection locations recovering refrigerant from the field. We reclaim at our Clayton, North Carolina facility, test in our own laboratory, which is listed in the AHRI Directory, and separate recovered mixed blends back into their component refrigerants. Each pound returned to service is a pound that stays out of the atmosphere.
Planning for the Next Number
GWP is regulated. PFAS is under scrutiny. TFA is now being measured. None of that requires a decision today, but it is worth knowing the TFA profile of the refrigerants you specify, stock and service, and knowing that lower-TFA options exist.
To learn more about R-4106A, visit fluorofusion.com/4106a or contact us at info@fluorofusion.com.
Sources
EFCTC: Published Evidence Supports Very Low Yields of TFA From Most HFOs and HCFOs
Tewari et al.: Atmospheric and Watershed Modelling of HFO-1234ze(E) Emissions (EGUsphere preprint)
EFCTC: Environmental Deposition of TFA Due to Long-Lived CFC Replacements and Anaesthetics
Food Packaging Forum: ECHA Committee Recommends Stricter Hazard Classification of TFA
EPA: Emissions Reduction and Reclamation Fact Sheet, September 2024
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