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Ecotoxicological information

Short-term toxicity to aquatic invertebrates

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Description of key information

OECD Guideline 202, EU Method C.2, GLP, key study, validity 1:

48h-EC50 (Daphnia magna) = 1.1 mg/L (95% CI: 0.95 -1.2 mg/L) based on time-weighted mean concentration

Key value for chemical safety assessment

EC50/LC50 for freshwater invertebrates:
1.1 mg/L

Additional information

One key study is available (Harlan, 2013) to assess the 48h acute toxicity of the registered substance to Daphnia magna, under semi-static conditions, according to OECD Guideline 202 and EU Method C.2 with GLP statement. 

Following a preliminary range-finding test, twenty daphnids (4 replicates of 5 animals) were exposed to an aqueous solution of the test item at nominal concentrations of 1.0, 1.8, 3.2, 5.6 and 10% v/v saturated solution (equivalent to time-weighted mean measured test concentrations of 0.28, 0.64, 1.2, 2.2 and 3.7 mg/L) for 48 hours at a temperature of 20 °C to 21 °C under semi-static test conditions. 

Chemical analysis of the test preparations at 0 hours showed measured test concentrations of 0.38, 0.67, 1.3, 2.3 and 3.8 mg/L were obtained. A slight decline in measured test concentration was observed in the old media at 24 hours in the range of 66% to 98% of the 0-Hour measured test concentrations. Analysis of the freshly prepared test preparations at 24 hours showed measured test concentrations to range from 0.39 to 1.4 mg/L whilst analysis of the corresponding old media at 48 hours showed a decline in measured test concentrations in the range of 39% to 78% of the 24-Hour fresh media test concentrations. As 100% immobilization was observed in the 5.6 and 10% v/v saturated solution test preparations after 24 hours exposure it was considered unnecessary to replenish the media.Given the decline in measured test concentration over each 24-Hour period it was considered appropriate to calculate the results based on the time-weighted mean measured test concentrations only.

The percentage of immobilization were 0, 0, 0, 15, 100 and 100 (24 hours) and 0, 0, 0, 65, 100 and 100 (48 hours) at 0, 0.28, 0.64, 1.2, 2.2 and 3.7 mg/L (time-weighted mean measured test concentrations), respectively.

 Under the test conditions and based on the time-weighted mean measured test concentrations, the 48-Hour EC50 value of 1.1 mg/L (95% confidence limits 0.95 – 1.2 mg/L).