Evaluation of effectiveness of EDTA and sodium thiosulfate in removing metal toxicity toward sea urchin embryo-larval applying the TIE

► TIE (Toxicity Identification and Evaluation) is used to work with complex mixtures. ► EDTA and sodium thiosulfate complex some metals in freshwater and seawater tests. ► Metal complexation by EDTA and thiosulfate were applied in embryo-larval tests with the sea urchin. ► The complexing agents, in seawater, have lower capacity to complex with the metals. ► Metals with lower EC50 values may present a reduction in toxicity after complexation.