The European Commission announced on January 12 that, under new rules in the EU’s recast Drinking Water Directive, member states must begin monitoring “in a harmonized way” per and polyfluoroalkyl substances (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 0.5 mcg/L or the “sum” of 20 specific PFAS to 0.1mcg/L. Notably the former limit includes trifluoroacetic acid (TFA), though the latter does not. TFA is an atmospheric degradation product of some HFOs and HFCs (such as HFO-1234yf, which converts entirely to TFA) and is also created via the breakdown of certain pesticides and pharmaceuticals, and from sewage treatment and industrial pollution.
“PFAS pollution is a growing concern for drinking water across Europe,” said Jessika Roswall, EU Commissioner for Environment, Water Resilience and Competitive Circular Economy. “With harmonized limits and mandatory monitoring now in force, member states have the rules and tools to swiftly detect and address PFAS to protect public health.”
The recast Drinking Water Directive was adopted in 2020, with member states required to transpose the directive into national law by January 2023. The recast directive “guarantees safer access to water for all Europeans and ensures world-leading standards for drinking water, in line with the Zero Pollution Action Plan and the Water Resilience Strategy,” the Commission said.
“PFAS pollution is a growing concern for drinking water across Europe.”
Jessika Roswall, EU Commissioner for Environment, Water Resilience and Competitive Circular Economy
EU member states are allowed to choose not to enforce the PFAS total in their countries, and several states have already decided not to implement this value, specifically Austria, the Czech Republic, Germany, Denmark, Spain, the Netherlands and Hungary. Germany, Denmark and the Netherlands have established drinking water advisories for TFA. Those countries still have to monitor whether the sum of the 20 PFAS – which include 10 perfluoroalkyl acids and 10 perfluoroalkyl sulfonic acids – exceeds 0.1mcg/L.
The countries will have to inform the Commission of monitoring results, including data on exceedances of the limit values, incidents and any granted exemptions. This is the first time systematic monitoring of PFAS, known as “forever chemicals,” in drinking water is to be implemented in the EU.
If the limit values are exceeded, member states must take action to reduce the level of PFAS, while also informing the public, the Commission said. These measures may include closing contaminated wells, adding treatment steps to remove PFAS or restricting the use of drinking water supplies for as long as the exceedance continues.
Focus on TFA
To support consistent monitoring across the EU, the Commission in 2024 issued technical guidelines on analytical methods for measuring PFAS total and sum of PFAS in drinking water, with special attention to TFA.
The Commission acknowledged that available TFA monitoring results from raw water sources across the member states indicate that TFA concentrations “may significantly exceed the Directive’s ‘PFAS Total’ parametric value.”
The health effects of TFA are currently being assessed by the World Health Organization (WHO) on the basis of the most recent scientific knowledge, the Commission noted, adding, “Depending on the results of this assessment, the WHO could issue new recommendations regarding TFA concentrations in drinking water.”
Meanwhile, the Commission recommended that in addition to measuring PFAS total, TFA should be separately measured. If the TFA value exceeds the PFAS total value, the results should be considered “inconclusive.”
EurEau, which represents Europe’s drinking and wastewater sector, stated in a position paper last year that the EU’s PFAS total parameter “is inadequate for TFA” and that “a specific TFA limit value in drinking water should be set based on health-derived criteria.” At the same time, EurEau noted that if TFA becomes classified as a “relevant metabolite” under the Drinking Water Directive, member states would have to impose a limit of 0.1mcg/L for TFA, which would be difficult for drinking water suppliers to meet.
Country guidelines for TFA
Several European countries have issued guidelines for acceptable levels of TFA in drinking water and food. Germany has set a health-based guideline value of 60mcg/L for TFA in drinking water and a “precautionary measure” of 10mcg/L. Denmark has set a TFA drinking water threshold of 9mcg/L, while the Netherlands has listed the lowest drinking water advisory, 2.2mcg/L.
In other guidelines for TFA ingestion, the Netherlands have come up with an acceptable daily intake (ADI) for TFA of 0.32mcg/kg bw (body weight)/day, and the Flanders region of Belgium has one at 2.6mcg/kg bw/day; these are far lower than the ADI of 50mcg/kg bw/day proposed by the European Food Safety Authority (EFSA) in 2014.
Following a request from the European Commission, EFSA is reviewing the health-based reference values for TFA in cooperation with the European Chemicals Agency (ECHA). EFSA and ECHA also received a joint request to evaluate the fate and behavior of TFA in soil and water.
ECHA has also started its consultation and expert evaluation of a German proposal to classify TFA as reproductively toxic under the EU’s classification, labelling and packaging (CLP) regulation.
The biggest regulatory effort is being undertaken by the EU, as ECHA evaluates PFAS proposals from five countries to restrict PFAS as a class, including f-gases and TFA. The ECHA is looking at regulating very persistent and mobile substances like TFA for which chronic exposure alone a concern.
