Don't be fooled—A no-observed-effect concentration is no substitute for a poor concentration–response experiment

Abstract

Renowned mathematician and science historian Jacob Bronowski once defined science as “the acceptance of what works and the rejection of what does not” and noted “that needs more courage than we might think.” Such would also seem to be the case with no-observed-effect concentrations (NOECs) and no-observed-effect levels in ecotoxicology. Compelling arguments were advanced more than a quarter of a century ago as to why the use of a model to describe the concentration–response relationship was preferable to an isolated metric, with the NOEC singled out as a particularly poor toxicity measure. In the ensuing years numerous articles critical of the NOEC have been written, with some calling for an..