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The European Food Safety Authority (EFSA), the EU agency that provides independent scientific advice on existing and emerging risks associated with the food chain, announced on July 22 that it has significantly lowered health-based guidance values for trifluoracetic acid (TFA), indicators of what is considered a safe level in daily food, beverage and drinking-water consumption.
One of the main sources of TFA in the environment is the 100% atmospheric oxidation of fugitive HFO-1234yf (used in car air-conditioning and commercial/industrial refrigerant blends) and to a lesser extent some other f-gases; the TFA is absorbed in rainfall and distributed in surface water and soil. TFA is also a byproduct of certain pesticides and other products.
EFSA elaborated on the new health-based guidance values for TFA – acceptable daily intake (ADI) and acute reference dose (ARfD) – in a summary and full report. The European Commission and EU member states will take EFSA’s findings into account when they discuss measures to protect consumers in food safety, water monitoring and chemical regulation, said EFSA.
EFSA’s experts lowered the ADI of TFA to 0.014mg/kg of bodyweight (bw) per day, down from the previous value of 0.05 set in 2017. The ADI is an estimate of the amount of a substance in food, beverages and drinking water that can be consumed daily over a lifetime without presenting an appreciable risk to health. The new ADI for TFA is about 3.5 times lower than the previous one.
EFSA also set a new ARfD for TFA of 0.07mg/kg bw. The ARfD is an estimate of the amount of a substance in food, beverages and drinking water that can be ingested in a period of 24 hours or less without appreciable health risk to the consumer. Last September EFSA proposed higher ADI and ARfD values – 0.03mg/kg bw and 0.6mg/kg bw, respectively (both based on the TFA salt sodium trifluoroacetate).
“EFSA’s updated health-based guidance values for TFA show that this PFAS chemical is more toxic than previously acknowledged.”
Esther Smollich, Senior Science and Policy Officer, HEAL
The updated ADI and ARfD values are based on an extended one-generation reproductive toxicity study in rats that showed TFA reducing levels of thyroxine – a hormone produced by the thyroid gland that plays an important role in regulating energy, growth, and body temperature. In its summary EFSA added that although TFA is “unlikely to damage DNA,” the animal studies also identified TFA effects on development and reproduction. The agency identified areas for further research, including “the potential of TFA for long-term toxicity and carcinogenicity and developmental immunotoxicity,” it said.
The agency explained its methodology as first identifying levels “where no harmful effects were seen” and then reducing it by a standard uncertainty factor of 100 “to account for variability, i.e. differences between animals and humans as well as differences between people (such as children or more sensitive individuals).” Given the limitations of the data, an additional factor of five was applied.
In an extended one-generation study of rats in 2021, chemical producers Solvay and Bayer claimed no adverse reproductive effects from TFA exposure. However, in a 2025 report challenging industry interpretations of TFA animal studies, Pesticides Action Network (PAN) Europe, contended that “a closer look reveals overlooked signs of harm in offspring, including reduced thyroid hormone levels, [changed] weight of reproductive organs (testes and epididymis), liver changes, blood biochemistry alterations, and sperm abnormalities, even at lower exposures.”
Request from Commission
EFSA’s updated ADI and ARfD values for TFA came in response to a request from the European Commission. The agency began with a call for toxicological data on TFA that ran from August 6 to October 7, 2024. This included pesticide assessments, studies considered by ECHA as part of its classification proposals and industry research from the TFA Task Force, which consists of companies that market chemicals forming TFA in the EU.
“EFSA worked closely with experts from EU countries, academia and other organizations, and invited them to contribute throughout the process, including in our working group,” the agency said, adding that it compiled 170 studies and position papers and received 177 comments in response to its public consultation.
Individual European countries have issued ADI guidelines for TFA in food and drinking water that are much more stringent than EFSA’s values. The Netherlands’ ADI for TFA is 0.32mcg (0.00032mg)/kg bw/day, while the ADI for the Flanders region of Belgium is 2.6mcg (0.0026mg)/kg bw/day.
TFA’s persistence and mobility have led to its proliferation in the environment in growing concentrations, including surface and groundwater, plants, drinking water, beverages, food and human blood serum. TFA is considered extremely difficult and expensive to remove from surface water, so exposure is continuous, though it has a short half-life in humans (reportedly two to three days).
PAN Europe, which has published studies on TFA in surface and drinking water in Europe, last year released studies of the growth of TFA in wine and bread/cereal products. In the wine study, which covered 10 EU countries, no TFA was detected in wine dated before 1988, but the amount of TFA progressively grew from 1988 (13mcg/L) to an average of 122mcg/L between 2021 and 2024. In the study of bread and cereal products in Austria, conducted by affiliated group Global 2000, TFA was discovered in organic rye (13mcg/kg), conventional cereal products (167mcg/kg) and conventional butter biscuits (420mcg/kg); the average concentration across 48 products was 119mcg/kg.
Because it contains a fully fluorinated carbon atom, TFA falls within the EU’s definition of PFAS (per- and polyfluoroalkyl substances) – known as forever chemicals – as an ultrashort-chain, two-carbon version. Longer-chain PFAS such as PFOS and PFOA (eight carbons) have been definitively linked to reproductive, developmental, liver, kidney, thyroid and immunological effects.
“EFSA’s updated health-based guidance values for TFA show that this PFAS chemical is more toxic than previously acknowledged,” said Esther Smollich, Senior Science and Policy Officer, Health and Chemicals, for the Health and Environment Alliance (HEAL). “We know that the clean-up of TFA and other forever chemicals alone is not a sufficient, affordable or plausible solution. To protect health, a robust EU-wide restriction of PFAS, including those contributing to TFA release like fluorinated gases and PFAS pesticides, is urgent.”
Pauline Cervan, Toxicologist at Générations Futures, a member organization of PAN Europe, believes EFSA’s health-based values for TFA are still “insufficiently protective.” The agency, she said, “continues to tolerate a high level of thyroid dysfunction as acceptable, while the potential impacts on the immune system and on brain development are underestimated.”
The European Chemical Industry Council (Cefic) did not respond to a request for comment on EFSA’s new TFA values.
EFSA has supported another study by Italian researchers, published in November 2025, that found that TFA reduced antibody production in human-relevant in vitro tests at levels similar to those caused by perfluorooctanesulfonic acid (PFOS), which has well-documented immunotoxic effects. A 2024 study concluded that TFA meets the criteria of a “planetary boundary threat” because of increasing planetary-scale exposure.
Other EU activity
EFSA’s evaluation of TFA is one part of the EU’s consideration of TFA and other PFAS chemicals. The European Chemicals Agency (ECHA) concluded in June that TFA, based on animal studies, should be classified and labelled as toxic to reproduction, persistent, mobile and toxic (PMT) and very persistent and very mobile (vPvM); ECHA’s opinion still needs the approval of the European Commission before it becomes legally binding in the EU.
Under another regulation called REACH (Registration, Evaluation, Authorisation and Restriction of Chemicals), the European Chemicals Agency (ECHA) is currently considering a sweeping restriction of PFAS that would ultimately ban certain f-gas refrigerants and TFA, with a possible enactment of regulations in 2028.
Meanwhile, the European Commission announced in January that, under new rules in the EU’s recast Drinking Water Directive, member states in 2027 must begin monitoring “in a harmonized way” PFAS levels in drinking water to ensure compliance with new EU limit values. The directive calls for the states to limit “PFAS total” (encompassing more than 10,000 substances) to 0.5mcg/L or the “sum” of 20 specific PFAS to 0.1mcg/L; the former limit includes TFA, though the latter does not.
In addition, the World Health Organization (WHO) recently concluded gathering data on 18 PFAS, including TFA, pertaining to six health endpoints, including cancer and immune system effects.
In defending the use of TFA-producing refrigerants, the fluorochemical Industry has pointed to the UN Environment Programme (UNEP) and its 2022 Environmental Effects Assessment Panel (EEAP) report. The report said that TFA is not bioaccumulative, is “not expected to pose significant risk to humans or the environment at the present time” and “is unlikely to cause adverse effects out to 2100.”
