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Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.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-Chloropropyl(dimethoxy)methylsilane is a liquid at ambient temperature and pressure, with a measured melting point of < -100°C at 1013 hPa and a measured boiling point of 187°C at 1013 hPa. It has a measured relative density of 1.0265 at 20°C, a measured kinematic viscosity of 1.2944 mm2/s at 20°C. The substance has a measured vapour pressure values of 67.2 Pa at 20°C, 94.4 Pa at 25°C and 440.3 Pa at 50°C.


The presence of higher concentrations of volatile impurities such as methanol (a hydrolysis product of the substance) can result in a lower flash point. The substance has a measured flash point in the range of 41 - 70°C. It has a measured auto-ignition temperature of 220°C at 1008 -1009 mBar. It is not explosive and not oxidising on the basis of chemical structure.


In contact with water, 3-chloropropyl(dimethoxy)methylsilane reacts rapidly (half-life = 0.1 h at pH 4, 1.3 hour at pH 7 and 0.03 h at pH 9 and 20-25°C, predicted) according to the following equation to produce 3-chloropropyl(methyl)silanediol and methanol:


Cl(CH2)3Si(CH3)(OCH3)2 + 2H2O → Cl(CH2)3Si(CH3)(OH)2 + 2CH3OH


Therefore, requirements for testing of water-based physicochemical properties for the substance are waived on the basis of instability in water. The properties of the hydrolysis products, 3-chloropropyl(methyl)silanediol and methanol, are assessed instead.


However, the properties of the parent substance, 3-chloropropyl(dimethoxy)methylsilane have been predicted using validated QSAR estimation methods. 3-chloropropyl(dimethoxy)methylsilane has predicted log Kow value of 3.2 and predicted water solubility value of 370 mg/l at 20°C.


Methanol is miscible with water, has low log Kow (-0.82 to -0.64) and high vapour pressure (12,790 Pa at 20°C) (OECD 2004a).


The saturation concentration in water of the silanol hydrolysis product, 3-chloropropyl(methyl)silanediol is limited by condensation reactions that can occur over time at loadings about 50 mg/l. However, it is very hydrophilic (calculated solubility is 6.0E+04 mg/l at 20°C using a QSAR method) and has a low log Kow (0.8, predicted). It is not surface active and does not undergo significant dissociation within the environmentally-relevant range. It is much less volatile than the parent substance, with a predicted vapour pressure of 0.018 Pa at 25°C.

Additional information