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Environmental fate & pathways

Biodegradation in water: screening tests

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Description of key information

Not readily biodegradable according to OECD criteria.

Key value for chemical safety assessment

Additional information

No data on ready biodegradability are available for the test item. However, regarding the structure of the test item no biodegradation is expected. The test item is regarded as not readily biodegradable according to OECD criteria.

Nevertheless, two studies on ready biodegradability are available for a structural analogue (EC 403 -720 -7). Both substances are similar in structure (Cr-complex), physico-chemical properties and ecotoxicoloical properties. Therefore, EC 403 -720 -7 can be used as a read-across:

In a ready biodegradability study according to OECD 301 B and under GLP the analogue substance was assessed over a 28 day period by the Modified Sturm Test (RCC Notox B.V. 1989). The nominal test concentrations were 10 and 20 mg/L. The biodegradation was found to be 14.1 % and 3.5 % for 10 mg/L and 20 mg/L test substance, respectively. The reference compound sodium acetate degraded with more than 60% during the exposure period, thus confirming suitability of the activated sludge. These findings are supported by a second study according to OECD 301 (Ciba-Geigy Ltd. 1986). The analogue substance was 13 % biodegradable after 28 d for 10 mg/L and 8 % biodegradable after 28 d for 20 mg/L. Therefore, the test substance is considered as poorly biodegradable.