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Environmental fate & pathways

Biodegradation in water: screening tests

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Description of key information

The test item was found to be not readily biodegradable based on the BOD5/COD ratio.

Key value for chemical safety assessment

Biodegradation in water:
under test conditions no biodegradation observed

Additional information

The COD and BOD of the test item were determined according to EU Method C.6 and EU Method C.5 respectively in a GLP compliant test.

The COD was measured based on the reflux of the substance in the presence of mercury (II) sulphate with potassium dichromate and silver catalyst in strong sulphuric acid for a fixed periode of time. The non oxidized dichromate was titrated with ammonium iron (II) sulphate. In the conditions of the test, the COD of the test item was 2.518 mg O2/mg while the ThOD was 2.506 mg O2/mg.

The BOD was measured using the Winkler method during a 28 days test in presence of an inoculum and with 2 mg/L of active substance. The BOD values were: 0.110 mgO2/mg after 5 days, 0.300 mgO2/mg after 15 days and 0.395 mgO2/mg after 28 days.

Thus the biodegradation values were: 4.4%, 11.9% and 15.7% after 5, 15 and 28 days respectively.

Based on these results, the test item is considered as not readily biodegradable.