Registration Dossier

Environmental fate & pathways

Biodegradation in water: screening tests

Currently viewing:

Administrative data

Link to relevant study record(s)

Description of key information

The test item was investigated for its ready biodegradability OECD 301 F (1992) test under GLP conditions. After 28 days exposure the mean biodegradation of the test substance amounted to 77%. Consequently, the test substance was found to be biodegradable by 77% under the test conditions within 28 days. However, the pass level for ready biodegradability, i.e. biodegradation of at least 60% of the ThOD in a 10-day window within the 28-day period of the test, was not reached. However, the 10 day window is not applicable for the test substance, as the test substance is a multi-constituent substance. The test substance is regarded as readily biodegradable. Furthermore, this conclusion is supported by another non-GLP study.

Key value for chemical safety assessment

Biodegradation in water:
readily biodegradable

Additional information

The test item was investigated for its ready biodegradability in a manometric respirometry key test over 28 days according to the Commission Directive 92/69 EEC, C.4-D, Commission Regulation (EC) No 440/2008, C.4-D and the OECD Guideline for Testing of Chemicals No. 301 F (1992) under GLP conditions. The percent biodegradation of the test item was calculated based on the theoretical oxygen demand (ThOD) of 2.97 mg O2/mg test item. In the toxicity control, containing both 600095 Cyclohexylmagnol and the reference item sodium benzoate, the test substance had no inhibitory effect on the activity of activated sludge microorganisms at the tested concentration of 101 mg/L. In the procedure controls, the reference item sodium benzoate was degraded by an average of 95% by Exposure Day 14, and reached complete biodegradation (101%) by the end of the test (Day 28), thus confirming suitability of the activated sludge. The validity criteria were met. The biochemical oxygen demand (BOD) of the test substance in the test media significantly increased from about Exposure Day 7 until test termination after 28 days. At the end of the 28-day exposure period, the mean biodegradation of the test substance amounted to 77%. Consequently, the test substance was found to be biodegradable by 77% under the test conditions within 28 days. However, the pass level for ready biodegradability, i.e. biodegradation of at least 60% of the ThOD in a 10-day window within the 28-day period of the test, was not reached. However, the 10 day window is not applicable for the test substance, as the test substance is a multi-constituent substance. The test substance is regarded as readily biodegradable.

In addition a supporting test according to "The Guidelines for the hazard evaluation of new chemical substances (HJ/T 154-2004)" under GLP conditions was conducted. The test results of the test showed that, after 28 days test period finished, the accumulated percentage biodegradation of the test substance in activated sludge was 75.20%. The pass level of 60% degradation was reached at day 20.

 

Furthermore a supporting test according to an internal method equivalent to the OECD 301 C under non GLP conditions was conducted. The test was conducted with a pre-adapted activated sludge. After 28 days the test substance was 64 % biodegraded.