Ecotoxicological effects assessment: A comparison of several extrapolation procedures

Abstract In the future, extrapolation procedures will become more and more important for the effect assessment of compounds in aquatic systems. For achieving a reliable method these extrapolation procedures have to be evaluated thoroughly. As a first step three extrapolation procedures are compared by means of two sets of data, consisting of (semi)chronic and acute toxicity test results for 11 aquatic species and 8 compounds. Because of its statistical basis the extrapolation procedure of Van Straalen and Denneman is preferred over the procedures of the EPA and Stephan et al . The results of the calculations showed that lower numbers of toxicity data increase the chance of underestimating the risk of a compound. Therefore it is proposed to extend the OECD guidelines for algae, Daphnie , and fish with chronic (aquatic) toxicity tests for more species of different taxonomic groups.