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Ecotoxicological information

Toxicity to microorganisms

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Description of key information

In order to predict effects of chemicals in the environment and in biological waste water treatment plants, an activated sludge respiration inhibition test was performed. The toxicity

to activated sludge was determined in accordance with OECD Test Guideline 209, and in compliance with the OECD principles of Good Laboratory Practice.

The test is valid as shown by the EC50 of the reference compound 3,5-dichlorophenol (12 mg/L) and the coefficient of variation of the replicates of the control oxygen uptake rates

(9%). The average oxygen uptake rate for the control replicates is lower (16 mg O2/g dry weight/hour) than the prescribed rate (>20 mg O2/g dry weight /hour). This does not

influence the sensitivity of the activated sludge as shown by comparable EC50 values of the reference substance 3,5-dichlorophenol at oxygen uptake rates lower and higher than the

prescribed rate (AkzoNobel 2012). The lower average oxygen uptake rate does therefore not compromise the test outcome in terms of robustness of the endpoints obtained for the

test and reference substance and does not invalidate the test.

The toxicity of benzenesulfonic acid, C10-13-alkyl derivs., compds. with N,N-dimethyl-1,3 -propanediamine to activated sludge was determined at a contact time of 3 hours, using

various concentrations of the test substance. The inhibitory effect of benzenesulfonic acid, C10-13-alkyl derivs., compds. with N,N-dimethyl-1,3-propanediamine at a particular

concentration is expressed as a percentage of the two controls. From the results EC values were calculated. The EC50 of benzenesulfonic acid, C10-13-alkyl derivs., compds. with N,Ndimethyl- 1,3-propanediamine for activated sludge after 3 hours contact time is 200 mg/L with 95% confidence limits of 139 and 318 mg/L. The EC10 and EC80 values could not be

determined and the EC20 is 25 mg/L. Benzenesulfonic acid, C10-13-alkyl derivs., compds. with N,N-dimethyl-1,3-propanediamine is therefore considered not harmful to activated

sludge.

Key value for chemical safety assessment

EC50 for microorganisms:
200 mg/L

Additional information