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Ecotoxicological information

Short-term toxicity to aquatic invertebrates

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Description of key information

Read-across, OECD Guideline 202, non-GLP, key study, validity 2:
48h-EC50 (D. magna) = 8.25 mg/L (nominal concentrations).

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates
Effect concentration:
8.25 mg/L

Additional information

To assess the short-term toxicity of the registered substance, METHYL CIS-3-OXO-2-PENTYL-1-CYCLOPENTANE ACETATE, to aquatic invertebrates, one valid study is available.

This non-GLP study (Niikara, 1998), assessed as a key study, was performed on a read-across substance,METHYL 3-OXO-2-PENTYL-1-CYCLOPENTANE ACETATE (quality High Trans isomer), according to OECD Guideline 202 (1984). This read-across substance is a mixture of two diastereomers, approximately 10% cis- and 90% trans-diastereomers which cis-diastereomer corresponds to the registered substance. Daphnia magna were exposed to aqueous solution of the test substance containing 60 mg/L of the solvent HCO-40, at 0, 0.5, 1.0, 2.0, 3.8, 7.6, 15 and 30 mg test substance/L for 48 hours at a temperature of 20 to 21°C under static test conditions. The number of immobilised Daphnia and any adverse reaction to exposure was recorded after 24 and 48 hours. Analysis of the test substance concentrations was not a requirement of the 1984 Guideline and therefore was not performed in that study. However, the test substance is expected to be stable in the test solution: OECD TG 111, half-life pH 7 > 1 year (this was confirmed with the long-term toxicity study on Daphnia magna where nominal concentrations were relatively well maintained during static renewal conditions: 74 to 101% of nominal values), has been shown to be moderately soluble (>500 mg/L) and was not considered volatile in the physico-chemical studies. Therefore, nominal concentrations were used to determined EC50 values.

Based on results obtained, the 48h-EC50 of the test substance to Daphnia magna was determined to be 8.25 mg/L (95% CL: 6.53 -10.5 mg/L) and the highest tested concentration without observed effect was determined to be 1.0 mg/L after 48 hours.

This supporting substance is considered adequate for read-across purpose based on similar physico-chemical properties and the same readily biodegradability potential between the registered substance and the analogue material used.

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