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Ecotoxicological information

Toxicity to microorganisms

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Description of key information

EC50 > 1000 mg/L, NOEC = 1000 mg/L, OECD 209, Roulstone 2012

Key value for chemical safety assessment

EC10 or NOEC for microorganisms:
1 000 mg/L

Additional information

The effect of the test material on the respiration of activated sewage sludge was investigated in accordance with the standardised guideline OECD 209.

During the study activated sewage sludge was exposed to an aqueous dispersion of the test material at concentrations of 10, 100 and 1000 mg/L (3 replicates of the 1000 mg/L concentration) for a period of 3 hours at a temperature of 20 ± 2 °C with the addition of a synthetic sewage as a respiratory substrate. The rate of respiration was determined after 3 hours contact time and compared to data for the control and a reference item, 3,5-dichlorophenol.

Under the conditions of the test the 3 hour EC50 was determined to be in excess of 1000 mg/L and the NOEC was determined to be 1000 mg/L. It was considered unnecessary and unrealistic to test at concentrations in excess of 1000 mg/L. The reference item gave a 3 hour EC50 value of 11 mg/L (95 % confidence limits: 8.7 - 14 mg/L).

The study was performed in accordance with a standardised guideline and in line with GLP. The study was reported to a high standard, sufficient to assess the accuracy of the reported conclusions. The study was therefore assigned a reliability score of 1 in accordance with the criteria as defined by Klimisch (1997) and considered suitable for assessment as an accurate reflection of the test material.