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Environmental fate & pathways

Biodegradation in water: screening tests

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Description of key information

The test substance is not readily biodegradable

Key value for chemical safety assessment

Biodegradation in water:
under test conditions no biodegradation observed

Additional information

The ready biodegradability of the test substance was determined in a GLP-compliant study according to OECD Guideline 301A (CG, 1990). The initial test substance concentration was 40 mg/L based on DOC. Biodegradation of the test substance after 28 days was found to be 0%. No inhibition on the activity of the bacteria was observed in a inhibition control. The substance is to be considered not readily biodegradable.

Biological oxygen demand over 5 days (BOD5) was determined in a study performed according to the EEC, Annex V, part C.8 guideline (D&C, 1988). In this study, a mixed culture of bacteria (effluent of a Husman laboratory apparatus) was exposed to 1, 5, 10, 20, 50, 100, 200 and 500 mg of test substance/L. The BOD5 of the test substance, corrected by the blank control, was 0 mg/g oxygen. The chemical oxygen demand (COD) of the test substance was determined in a study performed according to the EEC, Annex V, part C.9 guideline (D&C) under GLP. In this study, 5 mg of the test substance were exposed to 148°C for 2 hours. The COD of the test substance was estimated 773 mg O2/g test item. The BOD5/COD ratio supports the conclusion that the test substance is not readily biodegradable.