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Ecotoxicological information

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Description of key information

Acute rangefinder studies conducted with fish, Daphnia and algae showed no toxicity at the highest concentration tested (10 mg L-1). Definitive studies were not conducted due to the poor solubility of the test item, as it was not possible to get significant amounts of the test item into solution.

In an activated sludge respiration inhibition test a 3h-NOEC of 3.2 mg L-1, 3h-EC10 of 31 mg L-1 and 3h-EC50 of >100 mg L-1 were determined based on inhibition of total respiration (without the nitrification inhibitor ATU). A 3h-NOEC of 1 mg L-1, 3h-EC10 of 20 mg L-1 and 3h-EC50 of >100 mg L-1 were determined based on inhibition of heterotrophic respiration (with the addition of ATU). In this study the test solutions were not filtered as filtered solutions are less relevant when assessing toxicity in a STP, and it is considered likely that the difference in results between this study and the other aquatic toxicity studies is due to the presence of undissolved test item.

Additional information

Rangefinder studies showed no toxicity at nominal concentrations up to 10 mg L-1 (highest concentration tested) for fish, Daphnia and algae. Analytical monitoring of both the organic ligand and platinum showed very low concentrations of platinum and the organic ligand could be detected in solution. As the test item is very poorly soluble and it was not possible to get more of the test item into solution, aquatic toxicity is not expected at the limit of solubility and this was demonstrated in the rangefinding studies. Definitive studies were not conducted for fish, Daphnia or algae.

An activated sludge respiration inhibition test was conducted with the test item. A 3h-NOEC of 3.2 mg L-1, 3h-EC10 of 31 mg L-1 and 3h-EC50 of >100 mg L-1 were determined based on inhibition of total respiration (without the nitrification inhibitor ATU). A 3h-NOEC of 1 mg L-1, 3h-EC10 of 20 mg L-1 and 3h-EC50 of >100 mg L-1 were determined based on inhibition of heterotrophic respiration (with the addition of ATU). In this study the test solutions were not filtered as filtered solutions are less relevant when assessing toxicity in a STP, and it is considered likely that the difference in results between this study and the other aquatic toxicity studies is due to the presence of undissolved test item.