Retrospective study of triclosan and methyl-triclosan residues in fish and suspended particulate matter: Results from the German Environmental Specimen Bank

► Triclosan and its transformation product methyl-triclosan were investigated in fish. ► Methyl-triclosan was found at higher concentrations than its parent compound. ► Levels of methyl-triclosan fish residues peaked between 2003 and 2005. ► Recently lower residues may be a result of a voluntary renunciation of triclosan use. ► Methyl-triclosan concentrations presumably pose no risk to aquatic organisms.