Registration Dossier
Registration Dossier
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EC number: 242-272-5 | CAS number: 18395-30-7
Dissociation constant
Administrative data
Link to relevant study record(s)
Description of key information
Dissociation constant (trimethoxy(2-methylpropyl)silane): Not relevant
Dissociation constant ((2-methylpropyl)silanetriol): pKa approximately 10
Key value for chemical safety assessment
Additional information
The requirement to test the substance for dissociation constant is waived because in contact with water the substance hydrolyses rapidly. The hydrolysis products in this case are (2-methylpropyl)silanetriol and methanol. There are no reliable measured data for the dissociation constant of (2-methylpropyl)silanetriol. The typical dissociation constants for the hydroxyl protons of silanetriols are available from studies in other silanetriols. It is appropriate to read-across dissociation constant data for (2-methylpropyl)silanetriol from phenylsilanetriol. This suggests that silanols are not expected to undergo significant dissociation within the range of pH relevant in the environment orin vivo. Phenylsilanetriol has a measured first dissociation constant ca. 10 in a reliable study using a relevant test method, (reliability 1; read-across conclusion is given reliability 2). Additional information is given in a supporting report (PFA 2013b) attached in Section 13 of the REACH technical dossier.
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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