Triflumezopyrim

Endpoint summary

Description of key information

The test substance is hydrolytically stable at pH 4, 7, and 9. Hydrolysis did not occur at these pHs when tested at 50°C. The hydrolytic half-life of the test substance was > 1 year. The test substance is susceptible to photolysis in pH 7 sterile buffer and natural water under irradiation using a xenon arc lamp to simulate natural sunlight. The photolysis half-life was 50.6 hours in pH sterile buffer and 67 hours in sterile natural water. In each of the irradiated test systems, it was demonstrated that [14C]-test substance degraded under irradiation. One major photodegradation product, identified as IN-RUB93, was detected in all irradiated test systems. This metabolite increased over the course of the study. Unidentified components consisted of multiple degradation products with no individual component accounting for >5% AR. The test substance was stable in the dark control samples under experimental conditions. The test substance dissipated slowly from the soil under anaerobic conditions. The DT50 and DT90 values for the test substance were 302.7 and 1005.6 days respectively. Analysis of soil extracts demonstrated that there were no major metabolites of >5% AR formed during the aerobic and anaerobic incubation period. Minor metabolites, IN-RPD47 and IN-SBY68 were observed at levels less than 5% AR. The rate of aerobic degradation was measured in several different soils. The DT50s in those soils ranged from 52.9 to 133.4 days. Two soil metabolites, IN-SBY68 and IN-RPD47 formed under aerobic conditions at >5% but <10% AR. In a separate study, when exposed to artificial sunlight under laboratory conditions, the test substance degraded photolytically on soil. The DT50 and DT90 values for the test substance in irradiated system were 12.1 days and 40.1 days, respectively forming major metabolites IN-RPA-19 and IN-Y2186 at >10% AR.

 

The test substance does not meet the criteria to be classified as readily biodegradable. In water the test substance degraded 4.6% after 28 days. In simulation tests in water and sediments, the test substance degraded slightly in the water compartment and partitioned to the sediment where it was further degraded to other metabolites that were eventually incorporated into the sediment as non-extractable residue. Multiple metabolites were observed in the water/sediment systems none of which accounted for more than 5% radioactivity. The DT50 in the water phase was 22.9 -67.3 days. Once in the sediment, the test substance degraded with an overall whole system DT50 of 282.9 -692.1 days.

 

The vapour pressure and Henry’s law constant of the test substance indicate that it has no potential to volatilize and therefore could not have any global warming potential (GWP), ozone depleting potential (ODP), photochemical ozone creation potential (POCP) or be expected to accumulate in the troposphere. The test substance is not listed in Annex I to Regulation (EC) No 2037/2000 of the European Parliament and of the Council of 29 June 2000 on substances that deplete the ozone layer and its subsequent amendments.