Leverett et al. commented on the Environmental quality standard (EQS) for diclofenac derived under the European Water Framework Directive [Leverett et al. (2021) Environ Sci Eur 33: 133 https://doi.org/10.1186/s12302-021-00574-z]. They postulated that the derivation of the EQS value for diclofenac is not conducted according to the EQS Technical Guidance, but rather using data of poor reliability and relevance. Consequently, the authors suggested using their alternative derived value instead. It is to be noted that the process for the EQS derivation for diclofenac is still ongoing and not finalized, and that as a consequence, any critical analysis is very premature. In general, within the current European Commission process, EQS values proposals are derived by expert groups led by the Joint Research Centre. In the specific case for diclofenac, Leverett et al. have also been actively involved as experts. This response to Leverett et al. (2021) aims to clarify the reasoning behind the proposal from a scientific point of view and to express our concern for the lack of transparency of their position in the statement of competing interests. Indeed, the authors did not disclose their participation in the expert group for deriving the diclofenac EQS value, nor that they have direct and indirect ties to a company that markets diclofenac in Europe, Glaxo Smith & Kline plc (GSK). This amounts to a significant conflict of interest and leads to disinformation to the reader.