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Environmental fate & pathways

Biodegradation in water: screening tests

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Description of key information

The percentage biodegradation of the test substance reached a mean of 16.3 % after 28 days based on its COD. Therefore the test item can be considered to be not ready biodegradable.The test item can be considered to be not ready biodegradable.

Key value for chemical safety assessment

Biodegradation in water:
under test conditions no biodegradation observed

Additional information

The readily biodegradability test was performed in accordance with EU method C.4, OECD guideline 301 D and OPPTS guideline 835.3110. Under the test conditions no biodegradation of this test item was noticed. The percentage biodegradation of the test item reached a mean of 16.3 % after 28 days based on its COD. Therefore the test item can be considered to be not ready biodegradable. The test item can be considered to be not ready biodegradable. According to the test guidelines the pass level for ready biodegradability is 60 % of COD. The reference item sodium benzoate was sufficiently degraded to a mean of 68.8 % after 14 days, and to a mean of 82.5 % after 28 days of incubation, based on ThODNH4. The percentage biodegradation of the reference item confirms the suitability of the used activated sludge inoculum. In the toxicity control containing both, the test item and the reference item, a mean of 30.0 % biodegradation was noted within 14 days and a mean of 33.6 % biodegradation was determined after 28 days of incubation. According to the test guidelines the test item can be assumed as not inhibitory on the activated sludge microorganisms because the degradation in the toxicity control group was higher than 25 % within 14 days.