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Environmental fate & pathways

Biodegradation in water: screening tests

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Description of key information

- OECD 301E (Experimental investigation, GLP guideline study): 89 % degradation after 28 days - readily biodegradable, fulfilling the 10-d window 
- OECD 302B (Experimental investigation, no information about GLP): 98,5 % degradation after 28 days - inherently biodegradable

Key value for chemical safety assessment

Biodegradation in water:
readily biodegradable

Additional information

Regarding biodegradation in water (screening tests) 2 experimental results (one key study, Klimisch score 1 as well as one supporting study, Klimisch score 2) are available for the test substance.

The key study was conducted according to OECD Guideline 301E (Mead,OECD301E,1996). The study was conducted in compliance with the Principles of Good Laboratory Practice (GLP). The test material was exposed to activated sewage sludge micro-organisms at a concentration of 40 mg C/I with culture medium in the dark at 24°C for 28 days. The degradation of the test material was assessed by the determination of dissolved organic carbon removal. Control cultures with inoculum and the standard material, sodium benzoate were used for validation purposes. All validity criteria were met. Degradation of the reference item was 97% after 28 days. The following data could be determined for the test substance :

•The degree of biodegradation was 89 % after 28 days.

•Degradation exceeded 10% on day 2 of the study and attained 82% on day 6 of the study and therefore satisfied the 10-day window validation criterion given in the OECD Guidelines.

Therefore the test substance is readily biodegradable following OECD 301 E/EU C.4-B.

 

The supporting study was conducted according to OECD Guideline 302B (Simec,OECD302B,1996). The degradation parameter was the DOC removal in the samples. After 28 days incubation 98,5 % degradation had occured. Due to this result the test substance can be considered as inherently biodegradable. Ethylene glycol was used as reference substance. After 14 days incubation the reference substance is degraded at least 70% within the 14d-window, confirming the inoculum and the test set-up to be appropriate .