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One study is available investigating the short-term toxicity of Isotianil to soil macroorganisms (OECD 207). The study was conducted with Eisenia fetida. Since no mortality occurred the study resulted in a LC50 (14d) > 1000 mg/kg soil dw.

Furthermore two studies investigating the toxicity of the test item to soil microorganisms are available. Effects on the activity of soil microflora were investigated in a carbon transformation test by Schulz (2012a). This study was conducted in compliance with GLP and according to the OECD test guideline 217. Microorganisms were exposed for 28 days to 0.80 and 8.00 mg test item/kg soil dry weight. No adverse effects of Isotianil on carbon transformation in soil were observed at either test concentration.

In a second study the effects on the activity of soil microflora were investigated in a nitrogen transformation test by Schulz (2012b). This study was also conducted in compliance with GLP and followed the OECD test guideline 216. Microorganisms were exposed for 70 days to 0.80 and 8.00 mg test item/kg soil dry weight. The test item Isotianil caused a temporary stimulation of the daily nitrate rate at the tested concentration of 0.80 mg/kg dry soil at time interval 7-14 days after application. However, no adverse effects of Isotianil on nitrogen transformation in soil could be observed at the tested concentration of 0.80 mg/kg dry soil, 28 days after application (time interval 14-28 days). Temporary stimulations of the daily nitrate rate were also observed at 8.00 mg/kg dry soil beginning at time interval 7-14 until time interval 42-56 days after application. However, no adverse effects of Isotianil on nitrogen transformation in soil could be observed at the tested concentration of 8.00 mg/kg dry at the end of the test, 70 days after application (time interval 56-70 days).

In conclusion, Isotianil tested in a field soil at concentrations up to 8.00 mg test item/kg soil (equivalent up to an application rate of 6 kg test item/ha) caused no adverse effects (difference to control < 25%) on the soil nitrogen transformation at the end of the 70-day incubation period.