SCHEER - Scientific Opinion on "Draft Environmental Quality Standards for PFAS total under the Water Framework Directive"

SCHEER WG on Water Framework Directive
SCHEER members: Marian Scott (Chair), Thomas Backhaus, Teresa Borges, Peter Hoet, Pim de Voogt (Rapporteur), Rodica Mariana Ion
External experts: Andrew Johnson, Jan Linders
Contact: SANTE-SCHEERec [dot] europa [dot] eu (SANTE-SCHEER[at]ec[dot]europa[dot]eu)
On request from: European Commission
Adopted on: 6-7 March 2025

The Water Framework Directive requires the Commission to identify Priority Substances among those presenting significant risk to or via the aquatic environment, and to set EU Environmental Quality Standards (EQS) for those substances in water, sediment and/or biota. The Commission’s final proposal of October 2022 included EQS (in water and biota) for the sum of 24 per- and polyfluorinated alkyl substances (PFASs) in surface water, and a QS (in water) for the same 24 PFASs in groundwater, but no (E)QS for PFAS total because of the difficulty of deriving an appropriate value. The European Parliament has proposed amending the Commission’s proposal to include an (E)QS for PFAS total in groundwater and surface waters. It argued that since there are thousands of PFASs, setting a QS for 24 PFASs would be insufficient. Therefore, the JRC drafted a dossier with proposed quality standards for PFAS total. Six options have been included in the draft dossier. Option 5 (a tiered approach based first on the sum of 24 individual PFAS and then on a PFAS total assessment using the DWD parametric value of 0.5 ug F/L) was considered to be the best option by DG JRC. The SCHEER was asked to evaluate the draft dossier together with 6 additional questions.

The SCHEER shares the goal of the Commission and the European Parliament to protect human health and the environment from all the PFASs present. However, the SCHEER maintains that this objective should be met by accumulating risk-based toxicological information on a chemical basis. The SCHEER emphasises that the current knowledge on the risks of PFASs for human health and the environment is insufficiently researched and that more information is needed regarding both hazards and exposure.

The SCHEER concluded that:

• Using total organic fluorine as a means for setting an EQS for “PFAS total” is incompatible with the legal definition of an EQS value.
• The available analytical methods for determining total organic fluorine might lead to both overestimating and underestimating the actual PFAS concentrations present depending on the conditions. Furthermore, the sensitivity of the available analytical methods for total organic fluorine is insufficient to determine relevant concentrations in the 1-100 ng/L range.
• Anchoring an EQS to a 500 ng/L threshold (as is done in Options 1-5), as for “PFAS total” provided in the DWD, is in contradiction to the principle of setting EQS values based on the most robust eco- and toxicological evidence.
• The DWD does not contain a definition of PFAS. As there are several definitions for PFAS available in the literature, it is unclear which PFAS definition is used in the DWD and whether or not this is compatible with the definition used in the draft EQS dossier on PFAS total.
• Given the multitude of different PFASs with qualitatively and quantitively different (eco)toxicological profiles that can be expected to co-occur in a given surface water body, anchoring an EQS to total fluorine concentrations in a water body might either be excessively or insufficiently protective.
• The SCHEER advises to add TFA to the list of 24 PFASs.

The SCHEER adopts therefore Option 6 ('No agreement on EQS derivation’) but recommends that the PFAS24 approach be extended, adopting an RPF approach to the 100 individual PFAS that can be reliably determined. The SCHEER advises that this be done as rapidly as possible to include any other individual PFASs as up to 100 individual PFASs can be reliably determined. Toxicity data for these additional compounds should be generated as soon as possible.

Keywords:

Per- and polyfluorinated alkylsubstances, PFAS, Water Framework Directive, environmental quality standards

Opinion to be cited as:

SCHEER (Scientific Committee on Health, Environmental and Emerging Risks), Final Opinion on “Draft Environmental Quality Standards for PFAS total under the Water Framework Directive", 6 March 2025.