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

Short-term toxicity to aquatic invertebrates

Description of key information

Freshwater
EC50 (48 h) >108 mg/L, NOEC 108 mg/L (reported as mg ai/L, active ingredient, values were corrected for sample purity), EPA OPP FIFRA 72-2, Thorn & Bussard 1999 (Daphnia magna)
Marine
LC50 (48 h) >68.1 mg/L, NOEC 68.1 mg/L (reported as mg ai/L, active ingredient, values were corrected for sample purity); LC50 (96 h) 60.1 (51.9-69.9 mg/L 95 % C.L.), NOEC 9.16 mg/L, EPA OPP IFRA 72-3, Thorn & Bussard 1999a (Mysid shrimp)

Additional information

The short term toxicity to both marine and fresh water invertebrates has been determined studies investigating the effects in the water flea Daphnia magna (freshwater) and Mysid shrimp Mysidopsis bahia. An additional study performed in the Eastern oyster Crassostrea virginica was provided as supporting information.

Thorn & Bussard (1999) was performed in freshwater, where Daphnia magna were exposed to the test material at a measured concentration of 108 mg/L under flow-through conditions. Under the conditions of the test no mortalities/immobilisation or abnormal behavioural effects were observed within the 48 hour study. The NOEC concentration was determined to be 108 mg/L and it can be said that the EC₅₀ is >108 mg/L.

 

Thorn & Bussard (1999a) was performed in marine water, using Mysidopsis bahia. Shrimp were exposed to the test material for 96 hours under flow-through conditions at measured concentrations of 5.68, 9.16, 15.6, 24.5, 40.9 and 68.7 mg/L. No mortalities were observed in any of the exposure groups within 48 hours, therefore the 48 hr EC₅₀ and NOEC were determined to be > 68.7 mg/L and 68.7 mg/L, respectively. Between 48 hrs and termination of the study mortalities were observed at concentrations ≥ 15.6 mg/L. The 96-hour LC₅₀ was determined to be 60.1 mg/L with 95 % confidence limits of 51.7 and 69.9 mg/L. The 96-hour NOEC was 9.16 mg/L based on the absence of mortality and sublethal effects at this and all lower concentrations.

 

Thorn & Bussard (1999b) was performed in marine water, using Crassostrea virginica. Oysters were exposed to the test material for 96 hours under flow-through conditions at a measured concentration of 103 mg/L. Neither mortalities nor inhibition of shell growth was observed. The 48 hr and 96 hr EC₅₀ were determined to be > 103 mg/L and the NOEC is 103 mg/L.

All three studies were performed according to GLP, in line with standardised guidelines, with a high standard of reporting and have therefore all 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: Marine 48 hr EC₅₀ > 68.7 mg/L; Freshwater 48 hr EC₅₀ >108 mg/L.