Tap water in many French cities, including Paris, has been found to contain significant levels of trifluoroacetic acid (TFA). Conducted by consumer rights group UFC-Que Choisir and environmental organization Générations Futures, the survey revealed that TFA was detected in 24 out of 30 water samples. Paris’ 10th district recorded the second-highest concentration of TFA at 6,200 nanograms per litre, trailing only the rural town of Moussac at 13,000 nanograms per litre.
According to Radio France Internationale (RFI), “20 of the cities had levels higher than the 100 nanograms per litre limit that the European Union will put on 20 regulated PFAS by 2026”. RFI reports that the study analysed the presence of 33 PFASs in the water, and found that, other than TFA, their concentrations were "in line with the standard chosen by France" - 100 nanograms per litre for a total of 20 specific chemicals.
TFA is a highly mobile and persistent fluorinated compound widely used in the chemical industry and serves as the final metabolite of various PFAS. There are a lot of different possible sources of TFA in raw water sources including pesticides and refrigerants. The Pesticide Action Network has detected widespread presence of TFA in European tap water, as well as in surface and groundwater. In 2024 the German Chemical Agency submitted a proposal to the European Chemical Agency (ECHA) in 2024 to classify TFA as toxic to reproduction. Currently, there is no specific EU limit for TFA in drinking water, surface water, or groundwater. However, in a significant move to address TFA pollution of water bodies, the European Commission is phasing out pesticides that belong to the group of PFAS pesticides and are a primary source of TFA: tritosulfuron, flufenacet and flutolanil.
Regarding EU regulation of PFAS as a group, the current European limits for PFAS in drinking water are 100 ng/L for a sum of 20 individual PFAS (which do not include TFA), and 500 ng/L for total PFAS concentration, as per the recast 2020 Drinking Water Directive. The OECD definition of the term PFAS (from 2021) has been used by the European Commission to establish technical guidelines to monitor the parameter “PFAS Total”; this definition includes TFA.
However, recognizing that TFA concentrations across Europe may significantly exceed the “PFAS Total” value, the guidelines propose to determine the TFA concentration separately and subtract it from the PFAS Total concentration. Otherwise, it is estimated that numerous waterworks would exceed the 500 ng/L limit for total PFAS due to TFA concentrations alone.
Removal of TFA through conventional drinking water treatment methods is not efficient, thus highlighting the importance of source reduction. EurEau, the European federation of national associations of water services, and European water sector association Water Europe, have called for health-derived limit values for TFA in drinking water, as well control-at-source measures to avoid TFA contamination in the environment.
