Reaction Mass of (1R)-1-[(1S)-3,3-dimethylcyclohexyl]ethyl formate and (1R,2S)-2,6,6-trimethylcycloheptyl formate

Short-term toxicity to aquatic invertebrates

Description of key information

An OECD TG 202 guideline study in compliance with GLP with aquatic invertebrates (Daphnia magna) is available for the test substance. Daphnids (20/concentration) were exposed to WAFs prepared at loading rates of 4.6, 10, 22, 46 and 100 mg/L under static conditions for 48 hours. Exposure was performed in vessels closed with a screw cap and minimal headspace in order to minimize the loss of the test substance due to evaporation. Analysis of the samples taken at the start of the final test showed measured concentrations of 3.19, 7.65, 16.0, 35.1 and 39.4 mg/L in the WAFs prepared at 4.6, 10, 22, 46 and 100 mg/L. During the exposure period the measured concentrations decreased slightly to respectively 2.58, 6.19, 13.9, 28.6 and 28.6 mg/L, i.e. by 13 to 27% below the initial measured concentrations. The average exposure concentrations (t=0 -48h; geometric mean) were calculated to correspond to 2.9, 6.9, 15, 32 and 34 mg/L. In the control 10% mortality was observed which was within the accepted guideline criterion of ≤10%. At a concentration of 2.9 mg/L no signs of immobility could be detected. First at concentration of 6.9 mg/L, a 25% immobility response was noted which increased to 100% at all higher concentrations. The study met the acceptability criteria prescribed by OECD guideline (202) and was considered valid. Based on these data, the 48 -h EC50 value is determined at 7.7 mg/L (95% C.L. is 6.7 -9.5 mg/L).

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Dose descriptor:

EC50

Effect concentration:

7.7 mg/L