1-(allyloxy)-2-methyl-1-oxopropan-2-yl 2-chloro-5-[3-methyl-2,6-dioxo-4-(trifluoromethyl)-3,6-dihydropyrimidin-1(2H)-yl]benzoate

Short-term toxicity to fish

Description of key information

Freshwater: 96 hour LC50 3.9 mg a.i./L, Oncorhynchus mykiss, EPA OPP 72-1, EPA 540/9-85-006, ASTM Standard E729-88a, Drottar & Swigert 1996a
Saltwater: 96 hour LC50 4.6 mg a.i./L, Cyprinidon variegatus, EPA OPP 72-3, EPA 540/9-85-009 and ASTM E729-88a, Roberts & Swigert 1996

Key value for chemical safety assessment

Fresh water fish

Fresh water fish

Effect concentration:

3.9 mg/L

Marine water fish

Marine water fish

Effect concentration:

4.6 mg/L

Additional information

Two studies have been provided to address short term toxicity to fish in freshwater and one study to address acute toxicity in marine water.

Drottar & Swigert (1996a) and Drottar & Swigert (1996b) determined the 96 hour LC50 for the test material in the freshwater species Oncorhynchus mykiss and Lepomis macrochirus respectively. Both studies were performed in freshwater under flow-through conditions. The analytical confirmed concentrations ranged from 1.5 to 8.3 mg a.i./L in the first study and from 1.4 to 9.3 mg a.i./L in the second study. O. mykiss was shown to be the more sensitive species with a LC50 value of 3.9 mg a.i./L, whereas the LC50 was determined to be greater than the highest concentration tested for L. macrochirus, > 9.3 mg a.i./L.. Based on mortality and clinical signs of toxicity the NOEC was considered to be 2.5 mg a.i./L for O. mykiss and 3.6 mg a.i./L for L. macrochirus respectively. As O. mykiss is the standard species, and the results from this study are more worst case, this study has been considered to be the key study for freshwater fish and the LC50 value from this study of 3.9 mg a.i./L has been taken forward for risk assessment.

The short-term toxicity to marine fish was determined in an acute toxicity study performed on Cyprinodon variegates, in line with GLP and in accordance with the standardised guidelines EPA OPP 72-3, EPA 540/9-85-090 and ASTM E729-88a. Organisms were exposed to the test material at measured concentrations of 0.96, 1.5, 2.6, 3.9 and 4.6 mg a.i./L under flow-through saltwater conditions for 96 hours. Under the conditions of the test mortality was observed at concentrations ≥ 3.9 mg a.i./L. By termination mortality had reached 5% and 50% in the 3.9 and 4.6 mg a.i./L exposure groups, respectively. Clinical and behaviour observations were noted at concentrations ≥ 3.9 mg a.i./L including surfacing and spotted discolouration. Based on these observation the 96 hour LC50was determined to be 4.6 mg a.i./L with 95% confidence limits of 4.4 and 5.1mg a.i./L. The NOEC were determined to be 2.6 mg a.i./L. The study is considered to be reliable, relevant and adequate for risk assessment purposes.

All studies were performed to a high standard, in line with GLP and in accordance with standardised guidelines. They have thus been assigned a reliability score of 1 in line with the principles for assessing data quality set out in Klimisch (1997). The available data are deemed to be relevant, reliable and adequate for the purposes of risk assessment.