Registration Dossier
Registration Dossier
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EC number: 946-797-7 | CAS number: -
Endpoint summary
Administrative data
Description of key information
Additional information
The registration substance is a multi-constituent substance containing four constituents, decamethyltetrasiloxane (L4, CAS 141-62-8), dodecamethylpentasiloxane (L5, CAS 141-63-9), hexamethyldisiloxane (HMDS, CAS 107-46-0) and octamethyltrisiloxane (L3, CAS 107-51-7).
The properties of the substance as a whole are relevant in the context of safe handling and use. In the environment, the individual constituents may behave independently of each other, and therefore for the purposes of assessing environmental fate and behaviour, the properties of the constituents are relevant. Therefore, both whole substance data (where available) and individual constituent data are reported.
The registration substance is a liquid at standard temperature and pressure, with a melting point of <-100.0°C and a boiling point of 159.2°C. It has a measured relative density of 0.8306 at 20°C and a measured vapour pressure of 390 Pa at 20°C. The substance is classified as Flammable Liquid Category 3 (H226: flammable liquid and vapour) according to Regulation (EC) No 1272/2008. This is on the basis of a measured flash point of 29.0°C and a measured boiling point of 159.2°C. It has a measured autoignition temperature of 345°C at 964 hPa and is not explosive and not oxidising on the basis of chemical structure.
The key physico-chemical properties of the constituents are presented in the table below:
Table: Key physicochemical properties of constituents of the substance
Property |
HMDS (107-46-0) |
L3 (107 -51-7) |
L4 (141-62-8) |
L5 (141-63-9) |
Molecular weight |
162.38 |
236.54 |
310.69 |
348.9 |
Log Kow |
5.06 |
6.60 |
8.21 |
9.3-9.5 |
Water solubility (mg/l) |
0.93 (at 23°C) |
3.4E-02 (at 23°C) |
6.7E-03 mg/l at 23°C |
7.0E-05 mg/l at 23°C |
Vapour pressure at 25°C (Pa) |
5500 |
530 |
73 |
7.8 |
Hydrolysis half- life at pH 7 (h) and 25°C |
116 |
329 |
728 |
728 |
Information on Registered Substances comes from registration dossiers which have been assigned a registration number. The assignment of a registration number does however not guarantee that the information in the dossier is correct or that the dossier is compliant with Regulation (EC) No 1907/2006 (the REACH Regulation). This information has not been reviewed or verified by the Agency or any other authority. The content is subject to change without prior notice.
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