Pyrasulfotole

Endpoint summary

Additional information

Experimental studies are available for several trophic levels. All studies were performed according to international guidelines and GLP. Two studies are available investigating the short- (M-075743-01-2) and long-term (M-822955-02-1) toxicity of the test item to the earthworm Eisenia fetida. The long-term study was performed according to OECD 222. Adult worms were exposed for 28 d to a series of test item concentrations (during two test runs), ranging from 0.3 to 1000 mg a.i./kg dry weight artificial soil. Following another 28 d the reproductive output of the removed earthworms was determined in the emptied test containers. Respective statistical evaluation of the combined dataset (including run one and two) revealed a 56-d NOEC (reproduction) of 18 mg a.i./kg dry weight soil and a 56-d EC10 of 10.3 mg a.i. /kg dry weight artificial soil. No statistical significant effects on survival and weight were observed in the tested concentrations. The short-term study was performed according to OECD 207 (GLP). Adult earthworms were exposed in an artificial soil system over a period of 14 d to a limit concentration of 1000 mg a.i./kg dry weight of soil. Mortality and biomass changes were determined after 14 d and were used to determine the effect concentrations. The LC50 (14 d) was > 1000 mg a.i./kg dry weight soil, the NOEC (14 d) was determined to be ≥ 1000 mg a.i./kg dry weight soil.
Two experimental studies are available investigating the potential effects of the test item on vegetative vigour (M-263656-01-2) and seedling emergence and growth (M-263640-01-2) of plants. The studies were performed according to OECD guideline 208 under GLP conditions.
For the vegetative vigour study (M-263656-01-2) ten species of non-target terrestrial plants (4 monocots and 6 dicots) were sprayed at various application rates of the formulation. All plants were at the two to four leaf stages on the day of application and test duration was 21 days following application of the test substance. Typical symptoms with the test item observed in this study were bleaching, chlorosis, necrosis and growth suppression and all species except for ryegrass exhibited some or all of these symptoms, the severity of which increased with dose rate tested. The most sensitive EC50 (21 d) endpoint was 0.003147 mg a.i./kg soil equivalent to 2.36 g a.i./ha for sugar beet plant biomass. The lowest NOEC (21 d) values were 0.0006 mg a.i./kg soil, equivalent to 0.45 g a.i./ha for shoot length (cucumber, oilseed rape and sugar beet) and shoot biomass (sugar beet).
For the seedling emergence and growth study (M-263640-01-2) ten species of non-target terrestrial plants (4 monocots and 6 dicots) were sprayed at various application rates of a formulation containing the test item and a safener. Visual observations for germination and phytotoxicity were made on test days 7, 14 and 21. Final assessments were made for germination (emergence), growth stage, plant survival, shoot height and shoot biomass (dry weight) 21 days after application against the untreated controls. The most sensitive EC50 (21 d) was 0.00816 mg a.i./kg soil equivalent to 6.12 g a.i./ha for tomato plant biomass. The lowest NOEC (21 d) was 0.001187 mg a.i./kg soil, equivalent to 0.89 g a.i./ha for tomato shoot length.
The effect on soil microflora was studied in two experimental studies investigating the nitrogen (M-080546-01-2) and carbon transformation (M-080753-01-2). The studies were performed according to OECD 216 (nitrogen transformation) and 217 (carbon transformation) under GLP conditions. For both studies a loamy sand soil was exposed for 28 d to concentrations of 0.07 mg and 0.33 mg test item/kg dry weight soil (application rates were equivalent to 0.05 kg and 0.25 kg test item/ha). In case of nitrogen transformation, Lucerne-grass-green meal was added to the soil (5 g/kg dry weight soil) to stimulate nitrogen transformation. The substance caused no adverse effects (OECD 216) on the soil nitrogen transformation (expressed as NO3-N-production) at the end of the 28 d incubation period. The NOEC (28 d) was therefore derived to be ≥ 0.316 mg a.i./kg soil. During the 28-day test, no influence on carbon transformation after addition of glucose to a loamy sand was recorded as well. The NOEC (28 d) was therefore reported as ≥0.316 mg a.i./kg soil.
Moreover, five experimental studies on the toxicity of the test item to birds according to GLP are available. None of them revealed any toxic effect.