English 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.
