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Ecotoxicological information

Toxicity to aquatic algae and cyanobacteria

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Description of key information

EC50 (72h) > 100 mg/l (nominal), based on dose range finding test

NOEC (72h) ≥ 100 mg/l (nominal), based on dose range finding test

Key value for chemical safety assessment

EC50 for freshwater algae:
100 mg/L
EC10 or NOEC for freshwater algae:
100 mg/L

Additional information

The toxicity potential of the substance to green algae was evaluated after 2 hours of exposure to different concentrations of the substance (ranging from 40 -1800 mg/l). Fluorescence parameters were measured on 2 ml algal suspension after 1 and 2 h of exposure. The ΕC50 (2h) was determined to be 1098.1 ± 13.7 mg/l.

A second study is performed.

This study is performed as a limit test in order to evaluate the toxicity of the test item in an acute immobilisation test under static conditions towardsDaphnia magna.Daphnia magnaStrauswas chosen in the guideline as a typical species of zoo-plankton. Young daphnia, aged less than 24 hours at the start of the test, are exposed to the test item for a period of 48 hours. Immobilisation is recorded at 24 hours and 48 hours and compared with control values. Not more than 10 % of the control daphnia should show immobilisation or other signs of disease or stress, for example, discoloration or unusual behaviour such as trapping at surface of water. The results are analysed in order to determine the EC50at 48 h is determined. 

A positive control was tested in a separate study to assure that the test conditions are reliable.

The limit test was chosen based on the results of the range finding test. Ten daphnids per concentration were exposed to 0 -1 -10 -100 mg/l and the immobilisation was observed at 24 and 48 hours. One daphnid was found immobilised at the highest tested concentration at 24 hours and at 48 hours. No daphnids were immobilised in the rest of the tested concentrations.

The EC50 at 48 h from the dose range finding test is therefore > 100 mg/l

Once the main study results are available, the specific endpoint will be updated and the PNEC will be calculated based on the effects determined