Reaction mass of (3R)-3-[(1R)-4-methyl-3-cyclohexen-1-yl]-1-butanol and (3S)-3-[(1R)-4-methyl-3-cyclohexen-1-yl]-1-butanol

Toxicity to aquatic algae and cyanobacteria

Description of key information

EC50 (aquatic algae; growth rate)= 5.7 mg/L (C.I. 5.2 - 6.4 mg/L), 72 hour, freshwater, OECD 201, Vryenhoef 2013
EC10 (aquatic algae; growth rate)= 3.4 mg/L, 72 hour, freshwater, OECD 201, Vryenhoef 2013
NOEC (aquatic algae; growth rate)= 1.8 mg/L, 72 hour, freshwater, OECD 201, Vryenhoef 2013

Key value for chemical safety assessment

EC50 for freshwater algae:

5.7 mg/L

EC10 or NOEC for freshwater algae:

1.8 mg/L

Additional information

The algal growth inhibition to Pseudokirchneriella subcapitata, was carried out according to OECD 201 Freshwater Alga and Cyanobacteria, Growth Inhibition Test and EU Method C.3 guidelines. Following a preliminary range-finding test, Pseudokirchneriella subcapitata was exposed to a solution of the test item at nominal concentrations of 1.0, 3.2, 10, 32 and 100% v/v saturated solution (six replicate flasks) for 72 hours, under constant illumination and shaking at a temperature of 24 ± 1 °C. The test item solution was prepared by stirring an excess (300 mg/L) of test item in culture medium using a propeller stirrer for 24 hours. After the stirring period any undissolved test item was removed by filtration to produce a 100% v/v saturated solution of the test item. This saturated solution was then further diluted as necessary, to provide the remaining test groups. Samples of the algal populations were removed daily and cell concentrations determined for each control and treatment group. It was considered appropriate to calculate the results based on the geometric mean measured test concentrations. The study met the acceptability criteria prescribed by the guideline. The 72h-NOEC for growth rate reduction based on GMM concentrations was 1.8 mg/l. The EC50 for growth rate reduction (72h-ERC50) based on GMM concentrations was 5.7 mg/l (95% CL: 5.2 – 6.4 mg/l).