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Ecotoxicological information

Toxicity to aquatic plants other than algae

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Link to relevant study record(s)

Description of key information

The most critical NOEC and EC50 for higher aquatic plants were 80 and 1700 µg/L, respectively, obtained from a 14-d growth inhibition study with duckweed (Lemna minor) for the endpoint % surface coverage. These effect concentrations were obtained from the experiment with sodium selenite and will be used in the statistical extrapolation approach for determination of a waterborne PNEC.

Key value for chemical safety assessment

EC50 for freshwater plants:
1 700 µg/L
EC10 or NOEC for freshwater plants:
80 µg/L

Additional information

For aquatic plants other than algae 5 studies were identified originally. After review, 4 studies were retained as relevant. Of these 4 studies only one study was considered reliable (Klimisch 2). This study investigated the toxicity of SeO2, Na2SeO3, and Na2SeO4 to duckweed (Lemna minor) in a 14-d growth inhibition study according to the OECD 221 guideline (Jenner and Janssen-Mommen, 1993). Percentage surface coverage was identified as the most sensitive endpoint, yielding NOEC values of 800, 80, and 800 µg/L for SeO2, Na2SeO3, and Na2SeO4, respectively, whereas EC50 values of 2900, 1700, and 5300 µg/L were obtained for SeO2, Na2SeO3, and Na2SeO4, respectively.