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Ecotoxicological information

Toxicity to aquatic algae and cyanobacteria

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Description of key information

The substance was harmful to Desmodesmus subspicatus when tested according to OECD Guidelines for Testing of Chemicals (2011) No 201. The ErC50 observed after 72 hours was 24 mg/L.

Key value for chemical safety assessment

EC50 for freshwater algae:
24 mg/L
EC10 or NOEC for freshwater algae:
23 mg/L

Additional information

One toxicity study was performed to assess the acute toxicity of eugenol to the freshwater algae species Desmodesmus subspicatus (LAUS GmbH, 2013). The study was conducted under GLP and according to OECD Guideline 201. The study was conducted in a static system. Algae were exposed to the substance at a range of concentrations from 10 to 100 mg/L in freshwater. The test was performed with 3 replicates per test concentration and 6 replicates for the control. The following OECD 201 validity criteria were met: cell concentration in the control increased by a factor of 38 within 72h; the mean coefficient of variation of the daily growth rates were 33% and the coefficient of variation of average growth rate during the whole test period was 4%. However, the pH of the control changed by 1.9 units due to carbon dioxide decrease in the headspace as the carbon dioxide was absorbed during photosynthesis of the algae due to the closed test design; growth in the controls was normal. Under the conditions of the test, the 72 hour ErC50 was 24 mg/L, and therefore the substance is considered harmful to Desmodesmus subspicatus.