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Ecotoxicological information

Toxicity to aquatic plants other than algae

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Description of key information

EC50-values with 95 % confidence intervals for growth rate inhibition of frond number (ErC50) and dry weight (ErdwC50) were 103 (75.1 – 137) mg/l and 73.8 (54.1 – 102) mg/l, respectively.

EC50-values with 95 % confidence intervals for yield inhibition of frond number (EyC50) and dry weight (EydwC50) were 22.8 (13.5 – 37.4) mg/l and 17.6 (12.5 – 22.1) mg/l.

Key value for chemical safety assessment

EC50 for freshwater plants:
73.8 mg/L

Additional information

The effects of test item on lemna minor was determined according to the principles of OECD guideline 221 (2006).

A static exposure over 7 days was carried out. Based on a preliminary test, 5 nominal test item concentration levels were tested in a geometrical series with a dilution factor of √10: 2.00 - 6.32 - 20.0 - 63.2 - 200 mg/l.Three replicates were investigated for each test concentration and six for the control. Frond numbers were assessed on days 0, 3, 5 and 7. Environmental parameters light and temperature were within the acceptable limits.

The validity criteria of the test guideline were fulfilled.

Measured concentrations of the test item at 0 h were in the range of 93 to 101 % of the nominal values; measured concentrations of the test item at 7 d were in the range of 79 to 102 % of the nominal values, indicating that concentrations were successfully maintained for the duration of the test. The endpoints were assessed based on the nominal concentrations.

Effect levels in mg/l on frond number and dry weight were determined as for both growth rate and yield.