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 aquatic invertebrates

Description of key information

Freshwater: 48 hour LC50 > 8.6 mg a.i./L, Daphnia magna, EPA OPP 72-2, EPA 540/9-85-005, ASTM E729-88a, Drottar & Swigert 1996c
Marinewater: LC50 0.14 mg a.i./L, Mysidopsis bahia, EPA OPP 72-3, EPA 540/9-85-010, ASTM E729-88a, Roberts & Swigert 1996b

Key value for chemical safety assessment

Marine water invertebrates

Marine water invertebrates

Effect concentration:

0.14 mg/L

Additional information

One study has been provided to address short term toxicity to aquatic invertebrates in freshwater and two studies to address acute toxicity in marine water.

The short-term toxicity to freshwater aquatic invertebrates was determined in an acute toxicity study performed using Daphnia magna.The test was conducted in line with GLP and in accordance with the standardised guidelines EPA OPP 72-2, EPA 540/9-85-005 and ASTM E729-88a. Daphnids were exposed to the test material at measured concentrations of 1.6, 2.5, 4.4, 6.2 and 8.6 mg a.i./L under flow-through freshwater conditions for 48 hours. Under the conditions of the test, no mortality, immobility or clinical signs of toxicity were observed in daphnids exposed to the test material. Negative and solvent controls displayed a mean percentage mortality rate of 5%. Based on the observations made, the EC50was determined to be > 8.6 mg a.i./L, the highest concentration tested. The NOEC was determined to be 8.6 mg a.i./L.

The short-term toxicity to aquatic invertebrates was determined in an acute saltwater toxicity study performed on Mysidopsis bahia, in line with GLP and in accordance with the standardised guidelines EPA OPP 72-3, EPA 540/9-85-010 and ASTM E729-88a (Roberts and Swigert, 1996b). Organisms were exposed to the test material at measured concentrations of 0.043, 0.068, 0.12, 0.19 and 0.30 mg a.i./L under flow-through saltwater conditions for 96 hours. Under the conditions of the test mortality was observed at concentrations ≥ 0.12 mg a.i./L. By termination mortality reached 30%, 85% and 100% in the 0.12, 0.19 and 0.30 mg a.i./L treatment groups, respectively. Clinical and behaviour observations were noted at concentrations ≥ 0.068 mg a.i./L and included erratic swimming behaviour and lethargy. Based on these observation the LC50was determined to be 0.14 mg a.i./L at 96 hours, with 95% confidence limits of 0.12 and 0.16 mg a.i./L. The NOEC was determined to be 0.043 mg a.i./L. This study was chosen as the key study for marine water species on the basis that the endpoint values are more worst-case than the supporting study detailed below.

The short-term toxicity to aquatic invertebrates was determined in an acute saltwater toxicity study performed on Crassostrea virginica. The study was conducted in line with GLP and the standardised guidelines EPA OPP 72-3 and EPA 540/9-85-011 (Roberts and Swigert, 1996c). Oysters were exposed to the test material at measured concentrations of 0.82, 1.3, 1.9, 3.1 and 4.4 mg a.i./L under flow-through saltwater conditions for 96 hours. Under the conditions of the test shell growth inhibition was shown to be statistically significant (p≤0.05) in the 3.1 and 4.4 mg a.i./L exposure groups, with calculated inhibition of 70% and 88% respectively. Average shell growth at these concentrations was 0.70 and 0.27 mm in comparison to the pooled controls which was 2.33 mm. The 96 hour EC50 was determined to be 2.7 mg a.i./L, with 95% confidence limits of 2.5 and 2.9 mg a.i./L. The NOEC was determined to be 1.9 mg a.i/L.

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.