Registration Dossier
Registration Dossier
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EC number: 247-975-0 | CAS number: 26760-64-5
Short-term toxicity to fish
Administrative data
Link to relevant study record(s)
Description of key information
After 96 hours, the highest measured concentration at which no mortality had occurred was 2.93 mg/l and the lowest at which there was 100% mortality was 8.51 mg/l. Treatment-related effects were exhibited at 5.33 mg/l and higher concentrations.
Based on these findings the following values have been estimated: 96 hour LC50 value = 4.99 mg/l (95% confidence limits of 2.93 and 8.51 mg/l).
Key value for chemical safety assessment
Fresh water fish
Fresh water fish
- Effect concentration:
- 4.99 mg/L
Additional information
One reliable proprietary freshwater study, Huntingdon (2004a) is available for the isomer 2-methylbut-2-ene (CAS 513-35-9). Since isoamylene (2-methylbutene, CAS 26760-64-5) is a mixture of the two isomers, 2-methylbut-2-ene (CAS 513-35-9) and 2-methylbut-1-ene (CAS 563-46-2) and in the absence of any reliable data for isoamylene the data for the isomer (CAS 513-35-9) are considered suitable for read-across. After 96 hours, the highest measured concentration at which no mortality had occurred was 2.93 mg/l and the lowest at which there was 100% mortality was 8.51 mg/l. Treatment-related effects were exhibited at 5.33 mg/l and higher concentrations.
Based on these findings the following values have been estimated: 96 hour LC50 value = 4.99 mg/l (95% confidence limits of 2.93 and 8.51 mg/l).
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