N-[2,5-dichloro-4-(1,1,2,3,3,3-hexafluoropropoxy)-phenyl-aminocarbonyl]-2,6-difluorobenzamide

Endpoint summary

Description of key information

In a biodegradation screening study (OECD TG 301B), after 28 days exposure of activated sludge to 10.0 and 20.1 mg/L of the substance, -1 % (10.0 mg/L) and -2% (20.1 mg/L) biodegradation were determined. Based on these findings, the substance is considered to be not readily biodegradable.

The biodegradation of the substance in surface water : simulation test is waived due to the high insolubility of the substance. In addition, no further study on biodegradation in surface water is needed beyond the available simulation studies on soil and sediment. Two simulation studies on the biodegradation in water and sediment are performed according to standard test guideline and in compliance with GLP criteria. The key study represents the worst-case effects (i.e. showed higher DT50 values) of the water-sediment system. The effect values from this key study were used in a weight of evidence approach for the CSA. The arithmetic mean DT50 value was determined to be 112 days, under aerobic conditions in two different freshwater systems (river and Pond). In the same study, the arithmetic mean DT50 values of the major metabolites of the substance, M4 and M6, were determined to be 49.7 and 109 days, respectively.

Four studies are available for the biodegradation in soil: simulation tests endpoint. Three of them followed standard test guideline and complied with GLP (Reliability 1). One study (Reliability 2) did not follow standard test guideline but was well documented, met generally accepted scientific principles, and was compliant with GLP criteria. The effect values from all four studies were used in a weight of evidence approach for the CSA. The geometric DT50 value (n=6) was determined to be 18.3 days at 20 ˚C. No persistent major metabolites were identified in these studies.