Ethyl 2,6,6-trimethylcyclohexa-1,3-ene-1-carboxylate

Short-term toxicity to aquatic invertebrates

Description of key information

EC50 (invertebrates) = 17.4 mg/L 48hour-freshwater, OECD TG 202, Wil Research B.V. 2015

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

17.4 mg/L

Additional information

The acute toxicity to Daphnia magna was carried out according to OECD 202 Daphnia sp., Acute Immobilisation Test and EU Method C.2 guidelines. A limit test was combined with a range-finding test. Twenty Daphnia magna per test group (4 replicates, 5 daphnia per replicate vessel) were exposed to untreated control medium and to a concentration of 1.0, 10.0 and 100% of a 100 mg/L saturated solution in the limit test. No immobilisation was seen at 1.0 or 10% loading rates. 100% immobilisation at 100% saturated was observed. Ten daphnia per test group (4 replicates, 5 per replicate) in the definitive test were exposed to the following concentrations (nominal): 0 (control), 10, 17, 30, 52 and 90% of SS prepared at a loading rate of 100 mg/L and average exposure concentrations (measured): 0, 8.1, 14, 25, 40, 73 mg/L respectively. Samples for analytical confirmation of actual exposure concentrations were taken at the start and the end of the 48-hour test period. The measured concentrations remained stable during the test (100-110% of initial). No significant effects on the mobility of daphnia magna were observed up to and including 17 mg/L (initial), while an average of 90% immobile daphnia were observed at 30 mg/L (initial). There was no significant variation in the results of the combined limit/range-finding test and there were no significant responses at lower concentrations, furthermore test item concentrations were satisfactorily maintained during the course of the study. The 48h-EC50 was 17.4 mg/L based on initial concentrations which were analytically confirmed by measurement.