Registration Dossier

Environmental fate & pathways

Endpoint summary

Administrative data

Description of key information

Additional information

Phototransformation in air

Degradation rates for gas-phase reactions of the test substance with hydroxyl radicals and ozone in the atmosphere were calculated using the AOPWIN program, v1.92, which is based on the Atkinson structure-activity relationship method. . The calculated degradation rate of the test substance with hydroxyl radicals (OH) is 193.5 x 10E-12 cm3/molecule/sec. The atmospheric degradation half-life of the test substance due to reactions with ozone is 0.004 days.

 

Hydrolysis

The purpose of a study (Huntington Life Sciences, JHW0005, 2014) according to EPA OPPTS 835.2120 (Hydrolysis of Parent and Degradates as a Function of pH at 25°C, 1998) was to provide information on the hydrolytic degradation of the test substance when introduced into sterile aqueous solutions buffered at a pH of 4, 7 and 9. In water the test substance is stable to hydrolysis at pH 4 and pH 7, but hydrolytic degradation does occur under basic conditions (DT50 133 days at pH 9 and 25°C).

However, Hydrolysis is unlikely to be an important degradation process at most environmentally relevant pH and temperature levels.

 

Phototransformation in water

In a key study (Huntingdon Life Sciences, JHW0006, 2014) according to OECD 316 (2008) the test substance was photolytically degradable in both pH 7 buffer and natural water at 25°C. The test substance was readily degraded in sterile pH 7 buffer (DT50 = 17-28 days, 40°N) and natural water (DT50 = 10-12 days, 40°N), but stable in the dark control samples.

 

Phototransformation in soil

The photolysis of the radiolabelled test substance was studied in a test (BASF Crop Protection, 394791, 2013) on a soil obtained from New Jersey according to OECD guideline (Phototransformation of Chemicals on Soil Surfaces, Draft Document 2002). The DT50 of the test substance was determined to be 40.7 days for the sterilized soils in the dark control samples.

Thus, photolytic degradation of the test substance in/on soil did not appear to be an important dissipation pathway nor did the influence of light result in unique metabolites (photoproducts).

Metabolites observed in the soil photolysis study, including the dark control, were consistent with those from the aerobic soil metabolism study.