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Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.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

Environmental fate & pathways

Adsorption / desorption

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Description of key information

 Adsorption/desorption: Low potential for adsorption. 

Key value for chemical safety assessment

Additional information

Testing is waived in accordance with Column 2 of REACH Annex IX. The substance has a low potential for adsorption.

The substance is expected to hydrolyse very rapidly to form hydrogen chloride and silanediol. With further reaction of the Si-H bonds in silanediol, monosilicic acid and hydrogen are formed. Monomeric silanediol and monosilicic acid exist only in dilute aqueous solutions and readily condense at concentrations above approximately 100 -150 mg/l as SiO2 to give a dynamic equilibrium between monomer, oligomers and insoluble amorphous polysilicic acid.

Monosilicic acid is a naturally occurring substance, which will enter the natural biogeochemical cycle for silicon; adsorption/desorption studies are not relevant.

Based on their structure and predicted water solubilities, the hydrolysis products will have a high affinity for water and a low affinity for organic carbon and so a low potential for adsorption to the organic carbon. However, they may interact with the mineral content of soil. Amorphous polysilicic acid is a constituent of most soils.

In addition, adsorption testing with dichlorosilane is considered technically unfeasible because the substance is a gas at normal temperature and pressure, and is expected to react violently with water.