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Environmental fate & pathways

Biodegradation in water: screening tests

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Description of key information

Biodegradation: readily biodegradable, >=61 % degrad. (28-d) , OECD301D, Demares-Koopmans 2013

Key value for chemical safety assessment

Biodegradation in water:
readily biodegradable

Additional information

The ready biodegradability test was carried out according to OECD 301D (Ready Biodegradability: Closed Bottle Test)guidelines. The test substance, at a concentration of 1 mg/l and 3 mg/l, was exposed to secondary effluent activated domestic sewage sludge micro-organisms with mineral medium in sealed vessels at between 21.8 and 22.4°C for 28 days. Control solutions with inoculum and the reference substance, sodium acetate, together with a toxicity control were used for validation purposes. Oxygen concentration measurements were in duplicate; immediately at the start of the experiment (day 0), and at day 7, 14, 21 and 28. The relative biodegradation values calculated from the O2 measurements performed during the test period of 28 days revealed significant biodegradation of test substance at both concentrations. Mean biodegradation values between 62% and 71% were observed at 1 mg/l and values between 59% and 77% were observed at 3 mg/l. Biodegradation of at least 60% was reached within 14 days of biodegradation exceeding 10%. The test substance confirmed that mean biodegradation of at least 60% was reached within14 days of biodegradation exceeding 10%. In the toxicity control, the test substance was found not to inhibit microbial activity. All of the validity criteria for the test were met. The substance can be considered to be readily biodegradable.