STEFANIA GHEORGHE, CATALINA STOICA, IRINA LUCACIU, ALINA BANCIU, MIHAI NITA LAZAR ECOTOXICITY OF BIOCIDES (CHEMICAL DISINFECTANTS) - LETHAL AND SUBLETHAL EFFECTS ON NON-TARGET ORGANISMS The aim of this paper was to assess de ecotoxicity effects of four biocides, used as chemical disinfectants for swimming pool water treatment, on non-target organisms such as Daphnia magna and Heterocypris incongruens crustaceans. The tests showed a significant difference of sensitivity between species. The biocides, at the recommended disinfection doses, induced a very toxic or toxic effect on Daphnia magna, based on their mortality percentage. On the contrary, the observed ostracods lethal effects were generally less than 50% mortality and no significant growth inhibitions were observed. Overall, the ostracods had a higher tolerance to subacute doses, including disinfection doses of 20 mg/L (potassium mono persulfate), 5 mg/L (sodium dichloroisocyanurate), 8 mg/L (trichloroisocyanuric acid 90%) and 7 mg/L (trichloroisocyanuric acid 87-88%). In the context of a continuous biocides market expansion, the paper highlighted that our research proposed testing methods to obtain fast and accurate ecotoxicity data for a sustainable biocide production / authorization and also for an environmental hazard assessment.