The purpose of this work was to evaluate the mutagenic activity of ten priority compounds that were identified in the Danube River Basin in Europe for the construction of a database. The protocol used is a new miniaturization version of the Salmonella/microsome mutagenicity assay, called MPA (Microplate Agar), using TA98 strain. The ten compounds tested were negative for TA98, with and without metabolic activation (S9), except benzo(a)pyrene (Bap), which was positive in the presence of S9, as expected.