The French Agency for Food, Environmental, and Occupational Health and Safety (ANSES) has published the results of a two-year sampling and testing assignment for per- and polyfluoroalkyl substances (PFAS) in drinking water sources. ANSES found that the vast majority of analyzed samples fell below the applicable regulatory limits for PFAS, although at least one “forever chemical” was detected in more than 90 percent of samples.

Results from the assignment will be used as a baseline for understanding the presence of important PFAS in French drinking water and inform future PFAS monitoring. Specifically, the assignment was launched in response to Directive (EU) 2020/2184 on the Quality of Water Intended for Human Consumption, which established an initial list of 20 PFAS to be monitored in water distributed in France by January 12, 2026. ANSES’ latest assignment not only aimed to determine the presence of these 20 chemicals, but to identify other PFAS that could be monitored as well.

Between 2023 and 2025, ANSES tested for a total of 30 PFAS (15 in addition to the 20 mandated by the EU directive) in more than 600 raw and tap water samples each, collected across all of France and its overseas territories. The 15 additional PFAS types were selected for testing based on criteria like their physicochemical properties (i.e., their affinity for water) or evidence suggesting their presence in water. The samples came from catchment areas representing approximately 20 percent of the water distributed in France. Additionally, two-thirds of the samples were taken from locations identified by Regional Health Agencies as having a potential risk of PFAS contamination. 

Key findings from the sampling and testing assignment include:

• Of the 35 PFAS analyzed, 20 were detected in raw water samples and 19 in tap water samples.
• Of the PFAS listed in the EU drinking water directive, 11 were detected; most frequently, PFHxS (21.7 percent of tap water samples), PFOS (19.1 percent), and PFHxA (16.1 percent). Only a small proportion of samples exceeded 100 nanograms per liter (ng/L), which is the drinking water quality limit set in the EU directive.
• Of the remaining nine PFAS detected, four are classified as “conventional,” meaning PFAS composed of chains of more than three carbon atoms. These PFAS, especially 6:2 FTSA, were typically detected in samples that also contained at least one of the PFAS included in the EU directive, demonstrating that the PFAS included in the directive are good indicators for the presence of conventional PFAS.
• The other five PFAS detected are “ultra-short-chain,” meaning that they are made of molecules with one to three carbon atoms. These PFAS are not represented in the EU directive, and their presence appears to be independent of that of conventional PFAS. Of the short-chain PFAS, three were detected in multiple samples.
• TFA, a short-chain PFAS, was found in 92 percent of both raw and tap water samples, with a highly variable concentration from sample to sample, and a median concentration of 780 ngl/L in tap water.
• TFMSA, another short-chain PFAS, was identified for the first time in France, present in 13 percent of samples with a median concentration of 28.5 ng/L in treated water.

The results of the recent sampling and testing assignment complement an ANSES report published in October 2025, in which the agency recommended a scheme to improve PFAS monitoring, including in water. ANSES suggests that PFAS detected during the latest sampling and testing assignment could be integrated into the long-term water monitoring strategy recommended in the October 2025 report. The agency especially recommends including ultra-short-chain PFAS and conventional 6:2 FTSA, which, among PFAS not included in the EU directive, are more frequently found.