Ecotoxicity of a brominated flame retardant (tetrabromobisphenol A) and its derivatives to aquatic organisms

The large use of tetrabromobisphenol A (B 4BPA) in common products (plastics, electric and electronic equipments) has raised concern about its ecotoxicity. Physical and bio-degradations may lead to the formation of tetrabromobisphenol A derivatives like tri- (B 3BPA), di- (B 2BPA), monobromobisphenol A (B 1BPA) and bisphenol A (BPA). However, little is known about the toxicity of these brominated derivatives. An appraisal on the ecotoxicity of B 4BPA and its derivatives was carried out with several bioassays representing organisms (bacteria, algae, micro-invertebrates and fish) of different taxonomic groups present in aquatic ecosystems. Endpoint values showed that B 4BPA was significantly less toxic than the other chemicals when tested with the Microtox and algal asssays. A similar trend was observed with other bioassays for BPA. One of the brominated derivatives was particularly toxic: B 2BPA. The LuminoTox assay and the rainbow trout hepatocytes assay reported the most significant toxicity for this derivative. Its toxicity was also significantly higher than the other compounds barring B 3BPA when tested with the micro-crustacean test.