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Ecotoxicological information

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Results from National Institute of Technology and Evaluation are used mostly as key studies for aquatic toxicity, because they are most sensitive. The most sensitive acute toxicity is to aquatic algae (Selenastrum capricornutum) tested according to OECD TG 201 "Alga, Growth Inhibition Test". After 72 hours of exposure, an EC50 of 0.071mg/L and a NOEC of 0.023 mg/L were obtained. For chronic fish, a read-across approach from the hydrolysis product 2-mercaptobenzothiazol (MBT) was used to support the assessment, and a NOEC of 0.041 mg/L after 89 days was received. For TBBS a long-term study is available for aquatic invertebrates (Daphnia magna) tested according to OECD TG 202 part 2 reproduction test. After 21 days of exposure, an EC50 and a NOEC of > 0.16 mg/L were obtained. For the assessment of microorganisms in biological treatment plants, an EC50 value of > 10000 mg/L after 3 hours exposure was observed.

TBBS can be rapidly degraded by hydrolysis and photolysis, the hydrolysis half-life was determined to be 7.76 – 9.53 h. It is very likely that in the aquatic toxicity tests the observed effects were a combination caused by the parent substance and the degradation products.