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The European Food Safety Authority (EFSA) has significantly reduced the safe dietary level for the ultra-short-chain PFAS trifluoroacetic acid (TFA), citing concerns about endocrine effects. The agency also said further research is needed to assess TFA’s potential carcinogenicity and developmental immunotoxicity.
The authority’s decision brings new regulatory rules for the substance, which is a breakdown product of other fluorinated chemicals, including biocides, pesticides, pharmaceuticals and refrigerants.
In June, ECHA’s Committee for Risk Assessment (RAC) concluded that TFA should be classified as a category 1B reproductive toxicant and as a very persistent, very mobile (vPvM) chemical.
Some scientists have identified TFA as a "planetary boundary threat" due to potential impacts. Studies have found TFA in human urine samples, with exposure thought to come from consuming plant-based food and drinking water. EFSA said the available human biomonitoring evidence provides "qualitative support" for internal exposure to TFA.
On 22 July, EFSA experts lowered the acceptable daily intake (ADI) from 0.05 to 0.014 milligrams per kilogram bodyweight (mg/kg bw) per day. They also set a new acute reference dose of 0.07 mg/kg bw. The original ADI had been set following a pesticide risk assessment of the active substance flurtamone.
EFSA made its decision based on new evidence showing that TFA exposure led to reduced levels of the thyroid hormone thyroxine (T4) in an extended one-generation reproductive toxicity study in rats.
It added one uncertainty factor to account for differences between species and another to address a lack of data on long-term toxicity or carcinogenicity, as well as a potential for developmental immunotoxicity. The experts found that TFA is unlikely to be genotoxic.
Angeliki Lysimachou, head of science and policy at NGO PAN Europe, said EFSA’s assessment had some "shortcomings" but that it confirmed that "TFA is far more toxic than previously recognised".
Esther Smollich, senior science and policy officer at NGO HEAL, said the clean-up of TFA and other forever chemicals alone "is neither a plausible nor affordable solution. To protect health, a robust EU-wide restriction of PFAS, including those contributing to TFA release, like fluorinated gases and pesticides, is urgent."
The European Commission asked EFSA to assess TFA in 2024, and the authority then issued a call for data. In total, EFSA considered 170 studies and position papers, including data on pesticides that can release TFA and studies in RAC’s opinion.
Joint assessment
In January 2026, the Commission asked ECHA and EFSA to jointly assess the environmental fate and behaviour of TFA in soil and water, with a particular focus on releases from pesticides and biocidal products. In addition to scientific analysis, the agencies are exploring alternative methods for predicting TFA concentrations in groundwater and surface water. Their conclusions are expected next summer.
Meanwhile, the WHO is gathering data on 18 PFAS, including TFA, across six health endpoints:
- cancer;
- developmental effects;
- liver effects;
- immune system effects;
- cardiometabolic and metabolic effects; and
- reproductive effects.
The findings will support evaluations by the WHO’s Joint Expert Committee on Food Additives (JECFA).
Separately, in June, the US EPA proposed adding TFA and six other ultra-short-chain fluorinated compounds to the list of contaminants to be monitored in public water systems.