Registration Dossier

Physical & Chemical properties

Endpoint summary

Administrative data

Description of key information

Additional information

No reliable physico-chemical information was identified for isoamylene (CAS 26760-64-5) Instead, 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 then data for the two isomers are considered suitable for read-across. Data on physical properties were obtained from a number of secondary sources. The data in these secondary sources are based on a critical evaluation of peer-reviewed data and the selected values are considered to be reliable and representative of the property under investigation. Information on the review process was documented in the introduction of the source. The use of Klimisch codes (Klimisch et al. 1997) was extended to these secondary sources and a reliability code of (2) valid with restrictions was assigned when using the authoritative secondary source.

The substance is a volatile liquid of moderate solubility in water and is classified as a Category 1, hazard statement, extremely flammable liquid and vapour or a Category 2, hazard statement, highly flammable liquid and vapour depending on the boiling point of the substance. This classification is based on the flash point measurement of -20°C and a boiling point of 31.2°C (2-methylbut-1-ene), which meets the criteria of Category 1 for flammability (flash point <23 °C and boiling point35°C) and a boiling point of 38.56°C (2-methylbut-2-ene) which meets the criteria of Category 2 for flammability (flash point <23 °C and boiling point > 35°C).