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Ecotoxicological information

Toxicity to aquatic algae and cyanobacteria

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Description of key information

The 72-h ECr50 value and 72-h NOErC is 7.9 and 0.536 mg/L, respectively, in aquatic algae.

Key value for chemical safety assessment

EC50 for freshwater algae:
7.9 mg/L
EC10 or NOEC for freshwater algae:
0.536 mg/L

Additional information

The acute toxicity to aquatic algae was determined in a study according to OECD 201 and in compliance with GLP criteria. In this study freshwater green algae (Pseudokirchneriella subcapitata) were exposed to nominal concentrations of 0 (control), 0.250, 0.791, 2.50, 7.91, 25 mg/L for 72 hours under static conditions. Analytical confirmation of nominal test concentrations showed that concentrations of the test substance in test solutions were 0.167, 0.536, 1.75, 5.64, 18.9 mg/L. In the 18.9 mg/L block, growth was markedly inhibited throughout the exposure period. Growth was also inhibited in the 5.64 and 1.75 mg/L blocks, but logarithmic growth was achieved. Growth similar to the control block was observed in the 0.536 and 0.167 mg/L blocks. In the 18.9 mg/L block, a small number of swollen or aggregated cells were observed, but findings obtained in all other blocks were similar to those observed in the control block. No abnormality was observed in the control group. Based on these findings the 72 -h ErC50 and NOErC values were determined at 7.9 and 0.536 mg/L, respectively.