PFAS in Drinking Water

Guideline values for PFAS in drinking water have existed in some countries for a number of years (e.g. SE and DK). EU's revised drinking water directive (EU 2020/2184; DWD) will lead to a broader implementation across the member states. In the directive 20 PFAS are given and the sum of these has a limit of 100 ng/l. There is also an alternative parameter “PFAS total” of 500 ng/l, but the method to apply for measurement has not been decided upon yet. The limits have no direct connection to EFSA’s TWI value for PFAS4. In some countries such as DK, SE, DE and possibly BE in coming years, additional limit values for PFAS4 have been or will be introduced e.g. 2 and 4 ng/l in DK and SE, respectively. In comparison, these much lower levels have been derived from the EFSA TWI. In the case of SE and DK also PFAS20 have been extended with the addition of 6:2 FTS and PFOSA in DK and the former in SE. In NL there is since 2022 a guideline (recommendation) to sum up PFOA equivalents, similar to the proposed PFAS24 (see Environmental legislation – water), from an extended list of RPF (relative potency factors) with the limit 4.4 ng/l PFOA eqv (same a PFAS24) (RIVM, 2023)