A mixture of: 4-(2,2,3-trimethylcyclopent-3-en-1-yl)-1-methyl-2-oxabicyclo[2.2.2]octane; 1-(2,2,3-trimethylcyclopent-3-en-1-yl)-5-methyl-6-oxabicyclo[3.2.1]octane; spiro[cyclohex-3-en-1-yl-[(4,5,6,6a-tetrahydro-3,6',6',6'a-tetramethyl)-1,3'(3'aH)-[2H]cyclopenta[b]furan]; spiro[cyclohex-3-en-1-yl-[4,5,6,6a-tetrahydro-4,6',6',6'a-tetramethyl)-1,3'(3'aH)-[2H]cyclopenta[b]]furan]

Short-term toxicity to fish

Description of key information

The acute toxicity to fish was examined in a study according to OECD TG 203, and in compliance with GLP (Huntingdon, 1993). Groups of 10 rainbow trout (O. mykiss) were exposed to nominal concentrations of 0 (control), 0.56, 1.0, 1.8, 3.2, 5.6 and 10 mg/L for 96 hours under flow-through conditions. The test substance was dissolved in 10% Tween 80-acetone to give a series of stock solutions were dispensed automatically by the dosing apparatus into the flowing test water to give the desired series of exposure levels. Test substance analysis was performed at the start of the test and after 24 and 96 hours. Measured concentrations ranged from 87 -126% of nominal at 0 hours, 83 -94 % of nominal at 24 hours and 85 -99 % of nominal at 96 hours. Time-weighted average concentrations were determined to be 0, 0.52, 1.0, 1.6, 2.9, 5.4, and 10 mg/L. Mortality and type and incidence of sub-lethal effects was recorded at 3, 6, 24, 48, 72 and 96 hours after the start of the test. The validity criteria of the test were met.

No effects on mortality were observed up to the test concentration of 1.6 mg/L. At test concentrations of 2.9, 5.4, and 10 mg/L, cumulative mortality after 96 hours was recorded to be 20%, 90% and 100%, respectively. Based on these findings, the 96-h LC50 was determined at 3.8 mg/L (95% C.I. 3.0 – 3.9 mg/L) based on time-weighted average concentrations.

Key value for chemical safety assessment

Fresh water fish

Fresh water fish

Dose descriptor:

LC50

Effect concentration:

3.8 mg/L