Registration Dossier
Registration Dossier
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EC number: 201-083-8 | CAS number: 78-10-4
Henry's Law constant
Administrative data
Link to relevant study record(s)
Description of key information
Key value for chemical safety assessment
Additional information
Tetraethyl orthosilicate (CAS 78-10-4; EC No. 201-083-8) hydrolyses rapidly (t1/2 = 4.4 h at pH 7 and 25°C) in contact with water to form monosilicic acid (CAS 10193-36-6; EC No. 233-477-0) and ethanol (CAS 64-17-5; EC No. 200-578-6).
Monosilicic acid exists only in dilute aqueous solutions and readily condenses at concentrations above approximately 100-150 mg/l as SiO2 to give a dynamic equilibrium between monomer, oligomers and insoluble polysilicic acid. These are inorganic substances with a negligible vapour pressure, and which enter natural biogeochemical cycles for silicon. Therefore, volatilisation from water is not a relevant process.
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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