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Ecotoxicological information

Toxicity to terrestrial plants

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Description of key information

Cyclacet's EC10 in a long-term toxicity to terrestrial plants is 56 mg/kg soil dw, based on read across from Verdox, which was tested in an OECD TG 208. These values were converted using molecular weight and log Kow.

Key value for chemical safety assessment

Long-term EC10, LC10 or NOEC for terrestrial plants:
56 mg/kg soil dw

Additional information

The read across to Cyclacet is presented in the Terrestrial toxicity Overall Endpoint summary. The executive summary of the Verdox study is presented below.

Verdox long-term toxicity to plants

In a terrestrial plant test according to OECD TG 208 under GLP, 6 plant species were tested for seedling emergence, growth and phytotoxic effects (chlorosis, necrosis and abnormal growth). The test concentrations were verified in the stock solutions. The substance was mixed with quarts sand and thereafter mixed into the soil. The following dicotyles were used: Brassica napus, Glycine max, Solanum lycopersicum and Cucumis sativus. The following monocotyles were use: Avena sativa and Allium cepa. Doses were selected based on a dose range finding study and were 12.3, 37, 111, 333 and 1000 mg/kg soil dw for most species. Two additional concentrations were used for Brassica napus and Glycine max: 1.37 and 4.12 mg/kg dw soil. One additional concentration was used for Solanum lycopersicum: 4.12 mg/kg dw soil. The concentration in the stock solution was verified but actual measures in the soil were not performed. The soil is a sandy loam and was sterilised before use. All particles were < 0.2cm. The organic matter content is 0.67 ± 0.03 % and the pH was 5.9 ± 0.6. Untreated seeds were sewn in pots and plants were grown for 14 days, except Allium cepa which was grown for 21 days. Fresh weight of the leaves of plants was the more sensitive endpoint compared to germination, phytotoxicity and mortality. The EC10 of all six plant species was averaged as the number of species5. The overall EC10 on leaf fresh weight being the most sensitive parameter resulted in 44 mg/kg soil dw being the average of 6 plant species.