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Ecotoxicological information

Toxicity to microorganisms

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Description of key information

Disturbances in the biodegradation process of activated sludge microorganisms are not anticipated.

Key value for chemical safety assessment

EC50 for microorganisms:
1 000 mg/L
EC10 or NOEC for microorganisms:
320 mg/L

Additional information

Two studies investigated the effects of the test item to microorganisms. The key study was performed according to OECD Guideline 209 with activated sludge from a domestic waste water treatment plant (Feil, 2009). The study with a microbial community exhibited 15.9% inhibition of respiration rate at the highest test concentration of 1000 mg/L resulting in a NOEC of 320 mg/L and an EC20/50 of > 1000 mg/L. Cell growth inhibition with the single organism Pseudomonas putida was investigated in a second study according to DIN Guideline 38412, part 8 (Wichmann, 1991). An EC10 and EC50 of 12 mg/L and 50 mg/L resulted, respectively. But since this study was performed with a single organism an impact of degradation in sewage treatment plants is not anticipated as shown in the key study using a microbial community. Furthermore, the toxicity control in the biodegradation test showed no inhibition of activated sludge microorganisms. The reaction mass is therefore of low toxicity to activated sludge microorganisms and an impact of the degradation activity is not anticipated.