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Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.

The new ECHA CHEM database has been released by ECHA, and it now contains all REACH registration data. There are more details on the transition of ECHA's published data to ECHA CHEM here.

Diss Factsheets

Physical & Chemical properties

Endpoint summary

Administrative data

Description of key information

Additional information

Data on physical properties of 1,1 -dimethylheptanethiol (CAS 25360 -10 -5) were obtained from experimental data, a number of secondary sources and QSARs. 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 processes was documented in the introductions of the sources. 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 flash point of 1,1-dimethylheptanethiol (C9 branched) has been read across from structural analogues, octane-1-thiol (C8), dodecane-1-thiol (C12) and tert-dodecanethiol (C12 branched). These are straight and branched chain aliphatic thiols characterised by a sulfhydryl (SH) functional group with similar aliphatic carbon chain lengths. The substances are of a similar size and structure with a single unifying functional group and thus are expected to have similar physico-chemical properties. The flash point of octane-1-thiol is 70°C, dodecane-1-thiol is 128°C and tert-dodecanethiol is 95°C based on published and proprietary data and the flash point of 1,1-dimethylheptanethiol is expected to fall within this range.

The self-ignition temperature for 1,1-dimethylheptanethiol (C9 branched) has been read across from a structural analogue, tert-dodecanethiol (C12 branched). These are branched chain aliphatic thiols characterised by a sulfhydryl (SH) functional group. The substances are of a similar size and structure with a single unifying functional group and thus are expected to have similar physico-chemical properties. 1,1-dimethylheptanethiol and tert-dodecanethiol have similar melting points, both <-20°C and similar boiling points, 194°C and 156°C respectively. The self-ignition temperature of tert-dodecanethiol is 212°C based on proprietary data and the self-ignition temperature of 1,1-dimethylheptanethiol is expected to be similar to this value. Therefore following the similarities between the physico-chemical properties of the substances, a self-ignition temperature of 212°C for 1,1-dimethylheptanethiol has been read across from tert-dodecanethiol.

1,1 -dimethylheptanethiol is not currently classified under the DSD or the CLP. The flash point of 70°C and boiling point of 194°C indicate that 1,1 -dimethylheptanethiol would not be classified flammable. Based on its chemical structure, 1,1 -dimethylheptanethiol is not expected to be explosive or oxidising.