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Ecotoxicological information

Toxicity to aquatic plants other than algae

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Description of key information

ErC50 (Lemna minor, 7d, frond number) > 47.96 mg/L (meas. (geom. mean); corresponding to 100 mg/L nominal concentration)

Key value for chemical safety assessment

EC50 for freshwater plants:
47.96 mg/L

Additional information

The following data were obtained for Similar Substance 01. It is expected that the Target Substance will present similar effect levels to aquatic plants. Justification for the use of the Read Across approach is given in Section 13 of IUCLID.

The acute toxicity of Similar Substance 01 to aquatic plants was investigated in a 7–day static test using Lemna minor, according to the OECD Guideline 221 (2006). The study was performed using 6 concentrations ranging from 0.32 to 100 mg/L (nominal concentration). The frond number of each replicate was determined at the beginning, at day 3 and 6 during the test and at the end of the experiment. Additionally, the dry mass of each replicate was determined at the beginning and at the end of the experiment. Growth rate µ and the yield were determined from the frond number and the dry mass at the respective observation times. At the end of test, replicates with and without plants were analysed. The measured concentrations in the replicates with and without plants were within the same range, therefore, the measured values in the replicates without plants were used for evaluation.

The measured concentrations lay between 22 % and 47 % of the nominal concentrations at the beginning of the test and between 20 % and 51 % of the nominal concentrations at the end of the test (without plants). Therefore, the determination of NOEC / LOEC / ECx values was based on the geometric mean of measured concentrations. The 7d EC50 values of the positive control were determined in a separate reference test; the value of the growth rate lay within the desired range of 1.7 - 5.7 mg/L.

The ErC50 (Lemna minor,7d) for the test item were found to be > 47.96 mg/L based on frond number (geom.mean).