Can we still drink tap water? An eternal pollutant that is very complicated to remove from water, trifluoroacetic acid (TFA), has been identified in the water of a large majority of cities where it has been searched for, reports a study published this Thursday, January 23. Found in the water of 24 out of 30 municipalities, it alone exceeds, in twenty municipalities, the reference standard in Europe of 100 nanograms/liter for the twenty regulated PFAS, which must come into full force in 2026, according to this investigation carried out by UFC-Que Choisir and the environmental NGO Générations Futures. Their conclusion: the results are “alarming”
Almost indestructible, these “eternal pollutants” bring together more than 4,700 molecules and accumulate over time in the air, soil, rivers and even in the human body. If exposed over a long period, they can have effects on fertility or promote certain cancers, according to initial studies. If it is not, as the investigation writes, “as dangerous as PFOA or PFOS”, banned in Europe for several years, gray areas remain on the toxicity of TFA and it is “almost indestructible in the environment”, warns the study.
Among the 30 municipalities whose water was analyzed, Paris comes second in terms of concentration, with 6,200 ng/l, behind Moussac, in Gard (13,000 ng/l). The town of Bruxerolles, in Vienne, completes this podium, with 2,600 ng/l. Moussac is located near Salindres, where a Solvay group factory produced TFA until last September, the investigation recalls. “Certain areas, such as Tours or the surroundings of Rouen, present a real chemical cocktail, with respectively 10 and 11 different PFAS recorded in a single sample,” adds the study.
TFA, an endocrine disruptor?
In France, TFA is “very rarely – if not never – looked for by regional health agencies during drinking water checks” and the investigation highlights that it often comes from the degradation of flufenacet, a herbicide evaluated at the end of September by the European Food Safety Authority (EFSA). 0r this concluded, according to Générations Futures, that it is an endocrine disruptor.
“If an active substance [ici, le flufénacet] is an endocrine disruptor, then its metabolites [dont le TFA] must be considered by default as relevant” and therefore controlled, comments Pauline Cervan, toxicologist at Générations Futures, cited in the survey. Problem, TFA is “less well retained” than other PFAS by decontamination techniques water, both those based on activated carbons, as well as those based on membrane filtration, popular in the most modern drinking water factories, Julie Mendret, researcher at the University of Montpellier.
A French standard “too little protective”
The difficulty in retaining and therefore removing this chemical from water is explained by its characteristic as “short-chain PFAS”, which contains fewer carbon atoms and is therefore “very small, very mobile”, indicates this water treatment specialist. In addition to the TFA, Générations Futures and UFC-Que Choisir analyzed 33 PFAS: excluding TFA, the PFAS concentrations “remain compliant with the standard chosen by France” (sum of 20 specific PFAS limited to 100 ng/l).
But this standard is “much less strict than those of other countries” such as the United States or Denmark, note the two associations, which believe that the French standard “is far too little protective” and is not based “on any toxicological data solid”. These organizations call for the application of the precautionary principle. “With the American standard (4 ng/l for 2 PFAS), 6 samples (out of 30) including those from Rouen and Amiens would be considered non-compliant,” adds the study. If the real extent of the dangers posed by all of these substances on health remains unclear, this new investigation sounds the alarm.