Is the integration of hormesis and essentiality into ecotoxicology now opening Pandoraʹs Box?

Hormesis and essentiality are likely real and common effects at the level of the individual. However, the widespread incorporation of stimulatory effects into applications of ecotoxicology requires the acceptance of assumptions, value judgements and possibly lowering of water/sediment quality standards. There is also currently little data appropriate for considering hormetic effects in the ecotoxicological context. Except perhaps in the case of fitting concentration–response curves, it is not clear that incorporation of hormetic and essentiality type responses into ecotoxicology is necessary. Furthermore, its incorporation presents considerable intellectual and practical changes for ecotoxicology and could have unanticipated consequences.