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Ecotoxicological information

Toxicity to aquatic algae and cyanobacteria

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Reference
Endpoint:
toxicity to aquatic algae and cyanobacteria
Data waiving:
study scientifically not necessary / other information available
Justification for data waiving:
other:

Description of key information

In accordance with column 2 of Annex VIII of the REACH regulation, testing for this end point is considered scientifically unjustified since there are mitigating factors indicating that aquatic toxicity is unlikely to occur as the test substance is highly insoluble in water. And also having experimental partition coefficient value i.e. Log Pow is 5.4148 at 25 °C. Thussubstancecan be considered to be hydrophobic in nature. 

Key value for chemical safety assessment

Additional information

In accordance with column 2 of Annex VIII of the REACH regulation, testing for this end point is considered scientifically unjustified since there are mitigating factors indicating that aquatic toxicity is unlikely to occur as the test substance is highly insoluble in water. And also having experimental partition coefficient value i.e. Log Pow is 5.4148 at 25 °C. Thussubstancecan be considered to be hydrophobic in nature. 

Study: Objective of this study was to observe the action of test chemical when it exposed with the Desmodesmus subspicatus (previous name: Scenedesmus subspicatus) for 72 hrs. Test conducted in accordance with OECD Guideline 201 (Alga, Growth Inhibition Test). The stock solution 100 mg/l was prepared by dissolving colourless liquid in OECD growth medium. Test solutions of required concentrations were prepared by mixing the stock solution of the test sample with OECD growth medium and inoculum culture. 0, 12, 20, 34, 58 and 100 mg/l concentrations were use in the study. With the test substance one positive control Potassium dichromate (K2Cr2O7) was also run simultaneously. After the exposure of chemical, effect concentration EC50 was calculated using nonlinear regression by the software Prism 4.0. Effect on the growth of algae was determine after an exposure period of 72 hrs. Based on the growth rate inhibition of algae Desmodesmus subspicatus (previous name: Scenedesmus subspicatus) due to the exposure of test chemical for 72 hrs, ErC50 value was determine to be 53.5 mg/l. As the chemical was insoluble in normal water having partion log Pow 5.41, and in the above study chemical dissolved in the growth medium so that the solubility increases and the effect were observed. But on the above results chemical does not consider to be classified in the category of toxic chemical.