TFA: The Forever Chemical in the Water We Drink

Only a rapid ban on PFAS pesticides and F-gases can save our water

A recent exploratory survey of rivers, lakes, and groundwater conducted by members of the Pesticide Action Network (PAN) Europe showed alarming levels of contamination by the forever chemical TFA (trifluoroacetic acid) in all samples analysed across Europe. PFAS pesticides are considered the main cause of water contamination with TFA in rural areas, followed by refrigerants, sewage treatment, and industrial pollution. In the present study, we have analysed drinking water (both tap water and bottled water) for the presence of TFA. 

Test Results

  • TFA was detected in 34 of 36 European tap water samples (94 %) from eleven EU countries and in 12 of 19 bottled mineral and spring waters (63 %).
  • TFA values in tap water ranged from "undetectable" (corresponding to below the detection limit of 20 nanograms/ litre (ng/L1 )) to 4,100 ng/L, with an average of 740 ng/L.
  • TFA values in mineral and spring waters ranged from "undetectable" (below the detection limit of 20 ng/L) to 3,200 ng/L, with an average of 278 ng/L.
  • Analysis of 24 additional PFAS in 4 mixed samples confirms that, beyond contamination hotspots, TFA is the dominant (> 98 %) PFAS contamination in the water.

Health Implications

  • Assessing the health risks posed by environmental pollutants is always a challenge, especially when the data is sparse. This is the case with TFA, for which, given its widespread occurrence, surprisingly few toxicological studies are available.
  • Two recent studies on TFA's chronic toxicity and reproductive toxicity show similar effects to those of the better-studied and more well-known PFAS (liver toxicity and birth defects), albeit at much higher concentrations.
  • A drinking water guideline value for TFA that takes into account the current state of scientific knowledge of PFAS was proposed by the Dutch Institute for Public Health and the Environment (RIVM). Based on a risk assessment approach using relative potency factors for liver toxicity of PFOA, the RIVM has derived an indicative drinking water guideline value of 2,200 ng/L.
  • TFA was detected below this threshold in 97% of the tested samples. It was set in such a way that the consumption of drinking water only fulfils 20% of the tolerable daily intake.
  • Older guideline values for TFA are one to two orders of magnitude higher and give the impression of a large safety margin. However, their reliability appears limited as they are built on old data and optimistic assumptions.
  • Based on current scientific knowledge of the chemical's toxicity, the TFA levels we have found still appear to be within safety limits. However, the toxicity data are limited and incomplete, so underestimation of the risk cannot be excluded. Indeed, since many PFAS are considered non-threshold chemicals, it is reasonable to ask whether this also applies to TFA.
  • Moreover, TFA inputs are increasing day by day and our (assumed) safety buffer is limited - and is already filled by TFA entry pathways other than drinking water. In addition, we are unduly burdened by PFAS other than TFA. Measures to prevent further TFA contamination are therefore essential.

Legal Background

  • Although TFA is widespread, there is currently no legal limit in the EU for TFA in surface water, groundwater or drinking water.
  • In 2026, a standard limit value for "PFAS total" of 500 ng/L in drinking water is due to come into force in the EU. By definition, this value should also include TFA. However, as we understand, there are still discussions about how - and even whether this will be the case. As it stands today, and in light of our TFA results in drinking water, the following can be said:
    • Half of the tap water samples analysed exceed the limit value of 500 ng/L for "PFAS total" if TFA will be included in this parameter starting from January 2026. In this case, investments in the multi-digit billion range will become necessary to technologically upgrade the European drinking water supply to ensure that the limit value of 500 ng/L is not exceeded.
    • The end product of such a costly, non-environmentally-friendly high-tech purification process would be an 'artificial water' depleted of its natural components, which water companies would need to re-mineralize with high energy expenditure before supplying it to their customers.
    • There is still no clarity on the analytical method for monitoring the parameter "PFAS total", in particular on the question of how - and even whether - TFA can and should be detected with this method.
    • Member States can choose whether or not to include the parameter "PFAS total" in their national drinking water regulations. Some Member States, including Austria, the Czech Republic, Germany, Denmark, Spain, the Netherlands, and Hungary have not implemented this value.
    • The revision of the EU Water Framework Directive, expected to be finalised in trilogue before the end of 2024, opens the opportunity for the overdue establishment of quality standards (=limit values) for TFA in natural water bodies.
    • A revision of the EU Drinking Water Directive is (to our knowledge) currently under discussion and would allow the existing PFAS limits in drinking water to be brought in line with the state of the science, and also open up the possibility of setting an individual limit for TFA at European level.


While the TFA levels we have found appear to be still within what are considered safety limits, their input continues to increase with each passing day due to the use of PFAS pesticides and coolants ("F-gases"). And the “safety buffer” is small. To ensure that European citizens can still drink tap water safely in ten or fifty years' time, the governments that have enabled this pollution must now take swift and decisive action. The most important measures are as follows:

  1. An immediate ban on PFAS pesticides.
  2. An immediate ban on F-gases.
  3. Swift Implementation of the general PFAS restriction according to REACH.
  4. Establishment of a safe drinking water limit for TFA at EU level.
  5. Setting quality standards for TFA for waters regulated under the Water Framework Directive
  6. Wherever it is necessary to purify water due to chemical contamination, the Polluter Pays principle shall be applied
  7. Support to farmers in replacing the use of PFAS pesticides with other, ideally chemical-free, forms of crop protection.


© Pesticide Action Network Europe (PAN Europe), Rue de la Pacification 67, 1000, Brussels, Belgium, Tel. +32 2 318 62 55

Pesticide Action Network Europe (PAN Europe) gratefully acknowledges the financial support from the European Union, European Commission, DG Environment, LIFE programme. Sole responsibility for this publication lies with the authors and the funders are not responsible for any use that may be made of the information contained herein.