Abstract

Recently a hazard assessment on cationic surfactants was published in which it was concluded that cationic surfactants alone cause critical levels of pollution in the Dutch aquatic ecosystems. On behalf of the Directorate-General for Environmental Protection additional research was carried out to reduce uncertainties in the conclusion stated above. This report describes the supplementary toxicity studies carried out with DTDMAC, a major representative of cationic surfactants. The results of these studies are used to recalculate maximum permissible risk levels for DTDMAC. these were found to be ranging from 18 to 100 mug/l, depending on the calculation method and the confidence level chosen.