Registration Dossier

Ecotoxicological information

Endpoint summary

Administrative data

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Additional information

Acute toxicity to a number of freshwater fish species has been determined over a 96 hour period. The LC50 in rainbow trout was in excess of 1.4 mg/L, in fathead minnow was in excess of 1.3 mg/L and in bluegill was in excess of 0.73 mg/L. These values represent the highest concentrations examined which was at, or in excess of, the water solubility of the subsance. Acute toxicity to a marine species, sheepshead minnow, has also been determined. The 96 hour LC50 was in excess of 0.22 mg/L, the highest concentration investigated which was at, or in excess of, the water solubility of the substance

Acute immobilisation to Daphnia has been investigated over a 48 hour period. Entrapment on the surface occurred at higher concentrations, regarded as beyond the water solubility of the substance. The EC50 was > 0.022 mg/L and a NOEC of 0.0195 mg/L was established. A second study reports an EC50 of 15 mg/L. This concentration is in excess of the normal water solubility of the substance and was obtained by the use of solubilising agents.

An investigation of algal growth inhibition resulted in an EC50, based on cell numbers, after 72 hours and 8 days of >3.3 mg/L. The NOEC was 3.3 mg/L.

Long-term toxicity to fish has been determined in a fish early life stage test with rainbow trout. Under the conditions of the test the NOEC, based on the mean measured concentration, was 0.30 mg/L, the highest concentration investigated and regarded as the maximum water solubility under the test conditions.

A 21 -day chronic study on Dapnia magna resulted in a NOEC for survival and reproduction of daphnids of 0.059 mg/L. Another report of a 21 -day chronic test described no adverse effects on the reproduction of daphnia magna when compared with the test medium control or dispersion control. The NOEC was estimated to be 1.0 mg/L and the EC50 >1.0 mg/L. Solubilising agents were used to increase concentration of the substance beyond its water solubility.

Data on toxicity to microbial organisms has been derived from the toxicity controls used in ready biodegradation testing. A NOEC of 15 mg/L has been asssigned based on the concentration used in the ready bidegradability test(s).