2-Pyridinesulfonamide, N-[[(4,6-dimethoxy-2-pyrimidinyl)amino]carbonyl]-3-(2,2,2-trifluoroethoxy)-, sodium salt (1:1)

Toxicity to terrestrial arthropods

Description of key information

LD50 (48 h, oral) > 100 µg/bee, OECD 213, EPPO 170, Zenz 2002 
LD50 (48 h, contact) > 100 µg/bee, OECD 214, EPPO 170, Zenz 2002 

Additional information

The short term toxicity of the test material to terrestrial arthropods has been addressed in the two key studies in the honey bee (Apis mellifera) dosed via the oral and contact route both reported in the same study Zenz (2002). Supporting information was provided in the form of Kranzfelder (1999) and Kranzfelder & Malorin (1999), which investigated the acute contact and acute oral toxicity of the test material in honey bees, respectively. Zenz (2002) was selected as the key study as the two investigations were performed as a limit test in line with the maximum concentration recommended in the OECD 213 and OECD 214 guidelines for acute oral and acute contact toxicity in honeybees, respectively.

Two separate studies were reported in Zenz (2002), short term toxicity tests in bees performed via oral and contact dosing. In both studies bees were exposed to the test material in a limit test at 100 µg/bee. In both tests the rate of mortality was determined to be 3.3 % at 48 hours, the 48 hour LD₅₀ via the oral and contact routes were determined to be > 100 µg/bee. No significant signs of systemic toxicity were observed and the test material was determined to be none toxic to honey bees after short term exposure.

Kranzfelder (1999) determined the toxicity to honey bees in a contact test, where bees were exposed in a limit test at 25 µg/bee. No mortalities, signs of systemic toxicity or behavioural abnormalities were observed during the 48 hour observation period. The 48 hour contact LD₅₀ was determined to be > 25 µg/bee.

Kranzfelder & Malorin (1999) investigated the acute oral toxicity of the test material in bees at the following nominal concentrations; 0.0785, 0.157, 0.313, 0.625 and 1.25 µg/µL. The actual amount received by each replicate varied due to food consumption levels. The diet was weighed before and after exposure to quantify the amount of the test material that was consumed. Calculations showed consumption to be between 11 and 100 % and within the range 0.07 to 25 µg/bee. Under the conditions of the test the rate of mortality observed at 48 hours ranged from 0 to 30 %. As the mortality rate was less than 50 % the 48 hour oral LD₅₀ is therefore determined to be > 25 µg/bee. No signs of systemic toxicity were observed. the test material was considered to be none toxic.

All studies were performed according to GLP, in line with standardised guidelines, with a high standard of reporting and have thus been assigned a reliability score of 1 in line with the principles for assessing data quality set out by Klimisch (1997).

 

The available data are considered to be complete and the following conclusions for short term toxicity have been taken forward for risk assessment: Short term LD₅₀ > 100 µg/bee.