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Ecotoxicological information

Toxicity to microorganisms

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Description of key information

The EC50 for the test substance was found to be 465.32 mg/L.

Key value for chemical safety assessment

EC50 for microorganisms:
465.32 mg/L

Additional information

A study was conducted to evaluate the toxicity of the test substance to microorganisms according to OECD Guideline 209, EU Method C.11 and EPA Guideline OCSPP 850.3300, in compliance with GLP. Based on the results of a preliminary test, the activated sludge (from a domestic source) was exposed to the test substance at 62.5, 125, 250, 500 and 1,000 mg/L. The respiration rate of each mixture was determined after exposure periods of 3 h. An EC50 value was calculated from the respiration rates at different concentrations. A reference substance, '3, 5 -dichlorophenol', was used at 1.0, 3.2, 10.0 and 32.0 mg/L. In comparison to the inoculum controls the inhibition of the total respiration rate in the case of the activated sludge was between 8.18% and 77.72% in the examined concentration range of 62.5–1,000 mg/L of test substance. The 3 h EC50 of 3,5 -dichlorophenol (reference substance) was calculated to be 11.49 mg/L. Under the test conditions, the EC50 for the test substance was found to be 465.32 mg/L (Sipos K, 2015e).