(5-hydroxy-1,3-dimethyl-1H-pyrazol-4-yl)[[]2-(methylsulfonyl)-4-(trifluoromethyl)phenyl]methanone

Short-term toxicity to fish

Description of key information

Freshwater:

LC50 (96 h) >100 mg test item/L (M-103513-02-2, Oncorhynchus mykiss, nominal, OECD 203)

Marine water:

LC50 (96 h) >100 mg a.s./L (M-076735-01-1, Cyprinodon variegatus, nominal, OECD 203)

Key value for chemical safety assessment

Fresh water fish

Fresh water fish

Effect concentration:

100 mg/L

Marine water fish

Marine water fish

Effect concentration:

100 mg/L

Additional information

Three studies are available on the short-term toxicity of the test item to fish (M-103513-02-2, M-076735-01-1, M-103514-02-2). The studies were performed according to OECD guideline 203 and GLP, with analytical monitoring of the test item concentration. The mean recovery rates ranged between 93 and 100 % of nominal, respectively. Different test species were used in the three studies, one with marine (Cyprinodon variegatus) and two with freshwater species (Oncorhynchus mykiss & Lepomis macrochirus).

The key study with rainbow trout, Oncorhynchus mykiss (M-103513-02-2) was assessed in a static system. Juvenile rainbow trout were exposed to 0 (control) and 100.0 mg/L of the test substance designed as a limit test for a 96 hour period. All treatments had 10 fish per test vessel. Each test chamber was sampled for analysis of the test item at 0 hour and after 96 hours. The mean measured concentration of the test item was 96 mg/L representing 96% of the nominal concentration. Test solutions at 0 hour ranged from 97 to 100% of nominal concentration, while at 96 hours ranged from 93 to 94% of nominal concentration therefore, all toxicity values were calculated based on the nominal concentrations of the test item. No mortality or sub-lethal effects were observed in the control or 100 mg/L treatments during the study. The 96-hour EC50 of the test item to Oncorhynchus mykiss could not be determined under the conditions of this study and is greater than 100 mg/L. The no observed effect concentration (NOEC) was 100 mg/L. The lowest observed effect concentration (LOEC) could not be determined under the conditions of this study.

The second study with a freshwater species (M-103514-02-2) was conducted with bluegill sunfish, Lepomis macrochirus and was assessed in a static system. Juvenile bluegill sunfish were exposed to nominal concentrations of 0 (control) and 100.0 mg/L of the test substance for a 96 hour period. All treatments had 10 fish per test vessel. Each test chamber was sampled for analysis of the test item at 0 hour (test start) and after 96 hours (test end). The mean measured concentration of the test item was 97 mg/L representing 97% of the nominal concentration. Test solutions at 0 hour ranged from 96 to 98% of nominal concentration, while at 96 hours ranged from 94 to 98% of nominal concentration therefore, all toxicity values were calculated based on the nominal concentrations of the test item during the study. No mortality or sub-lethal effects were observed in the control or 100 mg/L treatments during the study. The 96-hour EC50 of the test item to Lepomis macrochirus could not be determined under the conditions of this study and is greater than 100 mg/L. The no observed effect concentration (NOEC) was 100 mg/L. The lowest observed effect concentration (LOEC) could not be determined under the conditions of this study. The test item would be classified as practically non-toxic to Lepomis macrochirus.

The key study (M-076735-01-1) for the marine compartment was conducted with a saltwater species sheepshead minnow (Cyprinodon variegatus). Fish were exposed in a static system over a period of 96 h to 0 (control) and 100.0 mg a.i./L of the test substance designed as a limit test. All treatments had 10 fish per test vessel. The mean measured concentration of the test item was 100% of the nominal concentration, therefore, all toxicity values were calculated based on the nominal concentrations of the test item. No mortality was recorded. The NOEC and LOEC in the 96-hour exposure of the sheepshead minnow (Cyprinodon variegatus) to the test item were >= 100 mg a.i./L and >100 mg a.i./L, respectively. The LC50 (96 h) was derived to be > 100 mg a.i./L.