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

SCHEER WG on Water Framework Directive
SCHEER members: Marian Scott (Chair), Marco Vighi (Rapporteur), Thomas Backhaus, Teresa Borges, Raquel Duarte Davidson, Peter Hoet, Pim de Voogt, 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: 5 December 2022

The dossier on Environmental Quality Standards for “Ibuprofen” is reviewed by the SCHEER according to the general mandate on EQS dossiers.

The proportion of the ibuprofen molecule that becomes neutral (hydrophobic), associated with higher uptake into cells, increases as the pH decreases. Whilst it is considered that 93% of European waterbodies are >pH 7, it is necessary that the Commission develops standards that are protective of all European waterbodies. The SCHEER, therefore, considers it appropriate that some way of extrapolating test data to a waterbody of a lower pH, i.e. of higher risk is made.

The SCHEER is in agreement with the comments in the dossier that no reliable acute study can be identified which may be used to derive an EQS. Therefore, also the derivation of an MAC_fw,eco is not possible.

A NOEC of 55 μg L^-1 was identified for Danio rerio, normalised to a NOEC for pH 6.5 as 6.88μg L^-1. The SCHEER accepts an AF of 10 could be used as a starting point – since also values for algae and crustacea were identified – and increased with an additional AF of 5 since relevant end-points like gonadal development were not included (giving a total AF of 50). Therefore, starting from the NOEC for Danio rerio of 6.88 μg L^-1 (pH corrected) a AA-QS_fw,eco of 6.88/50 = 0.138 μg L^-1 (rounded to 0.14 μg L^-1) is derived. With an additional AF of 10, a AA-QS_sw,eco = 0.014 μg L^-1 is derived.

The SCHEER questions the derived QS_{water,secpois}. The original correction factor (CF) was calculated as Ratio logD1/logD2 = 3.68 which was contradicted in section 3.4, where to calculate the CF = 10 ^{Δ log D} with Δ log D = log D1 - log D2, led to a CF of 21.88, leading to a QS_{water,secpois} = 0.064 μg L^-1.

Based on an identified ADI of 110 μg kgbw-1 d-1, a QS_{biota hh} of 13.5 mg kg_biota^-1 could be calculated for fish consumption. The SCHEER endorses this value.

The SCHEER agrees that a general conclusion on the toxicity of transformation products is not possible at the present state due to missing information on the complex degradation pathways.

Although a TL_hh is available, as there is no proposed value in the bioaccumulation section, the SCHEER agrees that no QS_hh,biota can be determined.

The critical EQSs are the QS_{water,secpois} = 0.064 μg L^-1 and the AA-QS_sw,eco =0.022 μg L^-1. However, several QSs have not been endorsed by the SCHEER or were impossible to derive. Therefore, the critical EQS must be considered as provisional.

Keywords:

Ibuprofen, 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 – ibuprofen, 5 December 2022.