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Environmental fate & pathways

Biodegradation in water: screening tests

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Description of key information

If released into water, the mixture is poorly biodegradable.

Key value for chemical safety assessment

Biodegradation in water:
under test conditions no biodegradation observed

Additional information

The objective of the biodegradation study conducted by Kung (1998) was to evaluate the ready biodegradability of the test substance using a respirometry test. The study was conduced according to principles specified in the OECD Ready Biodegradability Test method 301F (Manometric Respirometry Test). A defined medium with low mineral concentration and neutral pH was used to simulate the natural environment where biodegradation can occur. The return sludge from a domestic waste water treatment plant was chosen as the inoculum because of its diverse microbial population and high microbial activities. A measured volume of inoculated mineral medium was prepared containing 100 mg/L of the test substance as the nominal sole source of organic carbon. The mixture was continuously stirred in a closed flask at a constant temperature. The consumption of oxygen was monitored using an electrolytic respirometer system. After 28 days the level of biodegradation achieved for the test material was 5.9 %. The reference substance, sodium benzoate, reached a biodegradation level of 88.8 % in the same test period. The test substance was determined to be "Not readily biodegradable" under the given test conditions.