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Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.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

Vapour pressure

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Description of key information

Vapour pressure (2,2,4,4,6,6-hexamethylcyclotrisilazane): 35 Pa at 25°C (QSAR)

Vapour pressure (dimethylsilanediol): 7 Pa at 25°C (QSAR)

Vapour pressure (ammonia): 861100 Pa at 20°C

Key value for chemical safety assessment

Vapour pressure:
35 Pa
at the temperature of:
25 °C

Additional information

A predicted vapour pressure value of 35 Pa at 25°C was determined for the substance using a validated QSAR estimation method. The result is considered to be reliable.

In contact with water, 2,2,4,4,6,6-hexamethylcyclotrisilazane reacts very rapidly to produce dimethylsilanediol and ammonia/ammonium as products of hydrolysis. The vapour pressure of the silanol hydrolysis product, dimethylsilanediol is predicted to be 7 Pa at 25°C using a validated QSAR estimation method.

Ammonia has a reported vapour pressure of 861100 Pa at 20°C (OECD 2007).


OECD (2007). SIDS Initial Assessment Report for SIAM 24, Paris, France, 17-20 April 2007, Ammonia Category.