Oxidation by-products and ecotoxicity assessment during the photodegradation of fenofibric acid in aqueous solution with UV and UV/H2O2

► UV and UV/H2O2 photolysis of fenofibric acid. ► Identification of reaction intermediates using exact mass measurements. ► UV/H2O2 removed toxicity towards Pseudokirchneriella subcapitata. ► Irradiated samples contain a number of chlorinated products.