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Environmental fate & pathways

Biodegradation in water: screening tests

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Description of key information

Not readily biodegradable

Inherently biodegradable

Key value for chemical safety assessment

Biodegradation in water:
inherently biodegradable
Type of water:
freshwater

Additional information

The biodegradation of the substance in water was evaluated in different studies on similar substances. Supporting data by means of QSAR are also included.

A study was performed to assess the ready biodegradability of the similar substance in an aerobic aqueous medium, according to the OECD Guideline 301B (Modified Sturm test). The test substance, at a concentration of 15.0 mg organic carbon /L, was exposed to sewage treatment micro-organisms with mineral medium in sealed culture vessels in the dark at temperatures of 22 ± 2 °C for 28 days.

The degradation of the test item was assessed by the determination of the evolution CO2. Control solutions with inoculum and the reference item, sodium benzoate, together with a toxicity control were used for validation purposes. The test item attained 0 % degradation after 28 days and therefore cannot be considered to be readily biodegradable under the strict terms and conditions of OECD Guideline No 301B.

The inherent biodegradation of the same similar substance was evaluated according to the OECD Guideline 302 B. Activated sludge, domestic, adapted was exposed to the substance for 28 days. Mean biodegradation of the test item was 8% on Day 14 and 27% at the end of the 28 day test period.

Supporting (predicted by QSAR) data from other similar substances and also from the target substance suggest that the substance is not readily biodegradable