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Environmental fate & pathways

Biodegradation in water and sediment: simulation tests

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Description of key information

The test substance is rapidly degraded in sediment and water

Key value for chemical safety assessment

Half-life in freshwater:
2 d
at the temperature of:
20 °C
Half-life in freshwater sediment:
2 d
at the temperature of:
20 °C

Additional information

Reactive Black 5 was applied to a sediment/water test system at a final concentration of 1 mg/kg in the test system. The test substance (TS) was very rapidly degraded. The DT50 of the dye was 2 days. After 3 to 6 days, only 10% of the applied TS could be found. The two major identified metabolite were the bis-vinyl form, which further degraded to the hydroxy form. All metabolites decreased at the end of the test period to levels around the lower level of quantification. Consequently, an accumulation of metabolites could be excluded. The majority of the metabolites of the TS was deposited in form of non-extractable residues in sediment during test phase. After about 1 month, mineralization of the metabolites started.