Registration Dossier

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Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.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

3,3'-(1,1,3,3-Tetramethyldisiloxane-1,3-diyl)bispropylamine is a liquid at standard temperature and pressure, with a measured melting point of <-100°C, and a measured boiling point of 264.2°C. It has a measured relative density of 0.868 at 20°C, a measured kinematic viscosity of 4.7 mm2/s at 20°C and measured vapour pressure values of 0.27 Pa at 20°C, 0.87 Pa at 30°C and 11 Pa at 50°C.

The substance is not classified for flammability according to Regulation (EC) No. 1272/2008 on the basis of a measured flash point of 121°C and a measured boiling point of 264.2°C. It has a measured auto-ignition temperature of 284°C at 962 - 966 hPa, and is not explosive and not oxidising on the basis of chemical structure.

In contact with water, the substance hydrolyses slowly (half-lives of 1.0 h at pH 4, 63 h at pH 7 and 0.8 h at pH 9 and 20 -25°C) resulting in the formation 3-aminopropyldimethysilanol according to the following equation:

C10H28N2OSi2+ H2O → 2C5H15NOSi

Each amine group in the submission substance is basic and the neutral form is in equilibrium with the protonated form in solution, with the degree of ionisation dependent on pH (at neutral pH the doubly protonated species is predominant).


The unionised form of the substance has a predicted log Kow of 4.3. In solution, the amine group will protonate, therefore, the estimated log Kow for the unionised form was corrected for ionisation using the equation provided in the ECHA Guidance R.7a (2008). At pH 2, pH 4, pH 7 and pH 9, the corrected log Kow values are -3.7, -1.7, 1.3 and 3.2 respectively using pKa = 10. The substance has a predicted water solubility value of 120 mg/l at 20°C.

Additional information