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Ecotoxicological information

Endpoint summary

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The environmental toxicity profile of Diuron has been well defined. Short term and long term tests with species of 3 trophic levels are available for the substance.

The most sensitive trophic level to Diuron exposure proved aquatic plants as evidenced by EC50values for the growth rate ranging from 18.3 to 30.9 µg/L. Short term effects of the substance towards fish and daphnia were of a similar range. The EC50(48 h) values ranged from 1.4 to 22.6 mg/L in Daphnia magna while the LC50(96h) of fish was calculated to be14.7 mg/L. Thus, the test substance is acutely toxic to aquatic plants and organisms.

The long term effects of the test substance to aquatic organisms are investigated for fish andDaphnia, and were of a similar range. The most sensitive chronic toxicity tests using Daphnia magna revealed a NOEC of 0.56 mg/L and the chronic test with fish a NOEC of 0.41 mg/L.

The 30 minute EC50of the test item for respiratory inhibition of activated sludge was 3080mg/L. Since this is > 1000 mg/L, these findings indicate low toxicity of Diuron to sludge microorganisms and inhibition of the degradation activity of activated sludge is not anticipated.