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Ecotoxicological information

Toxicity to aquatic algae and cyanobacteria

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Description of key information

ErC50 (72 h) > 0.13 mg/L (Pseudokirchneriella subcapitata, OECD 201, based on time weighted average (TWA))

NOEC (72 h) ≥ 0.13 mg/L (Pseudokirchneriella subcapitata, OECD 201, based on time weighted average (TWA))

Key value for chemical safety assessment

EC10 or NOEC for freshwater algae:
0.13 mg/L

Additional information

One experimental study is available investigating the toxicity of the substance Decyl 2-ethylhexanoate (CAS 93777-46-9) to aquatic freshwater algae. The study was conducted according to OECD 201 (GLP) using the freshwater algae Pseudokirchneriella subcapitata. The algae cells were exposed in a combined limit/range-finding test over a period of 72 h to nominal test concentrations of 0.0010, 0.010, 0.10 and 1.0 mg/L. Due to a very low solubility of the test item in water (1.82 - 2.40 µg/L), stock solutions in acetone were prepared and spiked into test medium. Samples for analytical confirmation of actual exposure concentrations were taken at the start, after 24 and 72 h of exposure. Samples taken from the highest concentration were analyzed. The initially measured concentration was at the level of nominal but decreased to 12% of initial after 24 h of exposure and further to 0.27% of initial at the end of the test. This indicates that the initially measured concentration was above solubility limit in test medium (1.82 - 2.40 µg/L). The calculated TWA concentration was 0.13 mg/L. Under the conditions of the present study with Pseudokirchneriella subcapitata, no significant inhibition of growth rate was recorded at any of the concentrations tested. The EC50 (72 h) for growth rate inhibition was determined as > 0.13 mg/L (TWA) and the NOEC (72 h) for growth rate inhibition was ≥ 0.13 mg/L (TWA). Thus, no effect on algae growth up to the water solubility is expected.