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Ecotoxicological information

Short-term toxicity to aquatic invertebrates

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Description of key information

Determination of the ability of TK 12146 to induce acute toxicity to Daphnia magna after an exposure of 48 hours.

Key value for chemical safety assessment

EC50/LC50 for freshwater invertebrates:
0.75 mg/L

Additional information

This study was performed to assess the acute toxicity of the test item to Daphnia magna. The method followed was designed to be compatible with the OECD Guidelines for Testing of Chemicals (April 2004) No 202, "Daphniasp., Acute Immobilisation Test" referenced as Method C.2 of Commission Regulation (EC) No. 440/2008.

 

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 10, 18, 32, 56 and 100% v/v saturated solution for 48 hours at a temperature of approximately 20°C under static test conditions. The test item solutions were prepared by stirring an excess (50mg/L) of test item in test water using a propeller stirrer at approximately 1500 rpm for24hours. After the stirring period any undissolved test item was removed by filtration (0.2 µm Gelman Acrocap filter, first approximate 100 mL discarded in order to pre-condition the filter) to give a 100% v/v saturated solution. This saturated solution was then further diluted as necessary, to provide the remaining test concentrations. Immobilization and any adverse reactions to exposure were recorded after 24 and 48 hours.

 

Results:

Analysis of the test preparations at 0 hours showed measured test concentrations to range from 0.063 to 0.75 mg/L. There was no significant change in the measured concentrations at 48 hours and so the results are based on 0-Hour measured test concentrations only.

Exposure ofDaphnia magnato the test item gave the following results based on the 0-Hour measured test concentrations:

 

Time Point

(Hours)

EC50
(mg/L)

No Observed Effect Concentration (NOEC) (mg/L)

Lowest Observed Effect Concentration (LOEC) (mg/L)

48

>0.75

0.22

0.40

 

This study showed that the EC50is greater than the limit of solubility.