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Ecotoxicological information

Toxicity to aquatic algae and cyanobacteria

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Description of key information

The growth inhibition of the substance on the freshwater alga Scenedesmus subspicatus was tested by Huels AG (1996d) according to a test procedure similar to OECD- Guideline 201. The algae were exposed to 5 concentrations between 125 and 1000 mg/l and one control. 
Thursby et al. (1985) tested the effects of the test item on the marine red alga Champia parvula. Various biological endpoints, namely vegetative growth, formation of tetrasporangia (asexual reproduction) and production of cystocarps (sexual reproduction) were observed.

Key value for chemical safety assessment

EC50 for freshwater algae:
475 mg/L
EC10 or NOEC for freshwater algae:
64 mg/L
EC10 or NOEC for marine water algae:
29.9 mg/L

Additional information

Based on nominal concentrations, the 72h-EC10 value (based on biomass development) was determined as 64 mg/l and the EC50 as 475 mg/l (Huels AG, 1996).

In the second study (Thursby et al, 1985), the most sensitive endpoints after a 14 -day exposure period were found to be growth of tetrasporophytes and number of tetrasporangia exhibiting a LOEC of 49.8 mg/l. The next lowest test concentration was 60 % of this value, thus the NOEC is calculated to be 29.9 mg/l.