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

SCHEER WG on Water Framework Directive
SCHEER members: Marian Scott (Chair), Marco Vighi (Rapporteur), Thomas Backhaus, Teresa Borges, Peter Hoet, Pim de Voogt
External experts: Andrew Johnson, Jan Linders
Acknowledgements: Demosthenes Panagiotakos, Rodica Mariana Ion
Contact:SANTE-SCHEERec [dot] europa [dot] eu (SANTE-SCHEER[at]ec[dot]europa[dot]eu)
On request from: European Commission
Adopted on: 18 August 2022

The SCHEER was asked to evaluate the proposed quality standards for per- and polyfluorinated alkyl substances (PFAS) presented in an EQS dossier drafted by the JRC. The SCHEER is of the opinion that the concern for human health due to PFAS should not only focus on biota and drinking water but also on consumption of vegetables and fruit. The SCHEER considers the gap in the dossiers, due to missing ecotoxicity data for the period 2015-2021, a serious shortcoming and, therefore, recommends an update of the Draft EQS dossier.

The SCHEER endorses the use of Relative Potency Factors (RPFs) used in the derivation of quality standards for PFAS for humans. RPFs will, however, vary depending on the endpoint considered and therefore the SCHEER recommends monitoring the literature in order to signal possible new RPF data sets that may become available.

For five out of six PFAS, QSs could only be based on the deterministic approach. The SCHEER endorses the MAC-QS_fw,eco and MAC-QS_sw,eco values for PFBA (1.1 and 0.11 mg.L^-1, respectively), for PFPeA (3.2 and 0.32 mg.L^-1, respectively), for PFHxA (0.86 and 0.086 mg.L^-1, respectively) and PFBS (3.7 and 0.37 mg.L^-1, respectively). For PFOS the SCHEER endorses the MAC-QS_fw,eco of 0.025 mg.L^-1 but considers the value proposed for the MAC-QS_sw,eco to be incorrect and recommends that it should be changed into 0.0025 mg.L^-1. For PFOA both the deterministic and the SSD approach could be applied. The deterministic approach resulted in the lowest MAC-QS_fw,eco of 1.2 mg.L^-1, and the SCHEER cannot endorse this MAC-QS_fw,eco because it was not clear why an AF of 10 instead of 100 was applied. For the MAC-QS_sw,eco a lowest value of 0.012 mg.L^-1 was proposed, which is endorsed by the SCHEER.

The SCHEER confirms that the AA-QS_fw,eco and AA-QS_sw,eco values for PFOA (0.03 and 0.003 mg.L^-1, respectively), PFBA ( (0.11 and 0.011 mg.L^-1, respectively), PFPeA (0.032 and 0.0032 mg.L^-1, respectively), PFHxA (0.2 and 0.02 mg.L^-1, respectively), and PFBS (0.1 and 0.01 mg.L^-1, respectively) have been derived in agreement with the Technical Guidance. While this also holds for the AA-QS_fw,eco for PFOS of 0.023 μg.L^-1, according to the SCHEER the AA-QS_sw,eco value derived for PFOS is incorrect and the SCHEER proposes to set this value at 0.0023 μg.L^-1.

The SCHEER endorses the QS_sed of 13.5 μg.kg^-1_dw derived for PFOS for a sediment with 5% organic carbon. The SCHEER cannot agree with the conclusions that no QSsed is needed for PFOA, PFBS, PFBA, PFPeA and PFHxA, and recommends that more recent sediment studies should be evaluated in order to verify the correctness of current conclusions. The SCHEER endorses the tentative QSbiota,sec pois of 22.3 μg.kg_ww^-1 for fish and 6.2 μg.kg_ww^-1 for bivalves (PFOA equivalents). The SCHEER also endorses the QS_biota,hh of 0.077 μg.kg^-1_{biota ww} and the proposed QS_dw,hh of 4.4 ng.L^-1 (PFOA equivalents) and recommends to use this value also for protecting groundwater.

Although the majority of the MAC and AA values proposed for individual PFAS were derived in accordance with the TGD, the SCHEER is of the opinion that it would be more practical to embark upon a set of quality standards for the group of PFAS as soon as reliable RPFs for ecotoxicity are available, in line with the human health QS. Moreover, a discussion is lacking in the dossier on the relevance of the AA-EQS_fw and AA-EQS_sw for PFOS currently in force in the EU, both of which are substantially stricter than the AA-QS_fw and AA-QS_sw proposed in the dossier.

Due to the different approaches used in deriving QS_eco and QS_hh, as well as the identified gap in recent data on ecotoxicity it is not possible for the SCHEER to assess whether the most critical EQSs (in terms of impact on environment/health) have been correctly identified. For PFOS the most critical AA-EQSs would be the ones currently in force in the EU (0.00065 μg.L^-1 for inland surface waters and 0.00013 μg.L^-1 for seawater).

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 Priority Substances under the Water Framework Directive - PFAS, 18 August 2022.