Registration Dossier

Physical & Chemical properties

Dissociation constant

Currently viewing:

Administrative data

Link to relevant study record(s)

Description of key information

Scientifically not justified.

Key value for chemical safety assessment

Additional information

The dissociation constant study is waived because the substance is hydrolytically unstable.

There are no reliable measured data for the dissociation constant of methylsilanetriol. 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 methylsilanetriol from phenylsilanetriol. This suggests that silanols are not expected to undergo significant dissociation within the range of pH relevant in the environment or in vivo.

Phenylsilanetriol has a measured first dissociation constant approximately 10 in a reliable study using a relevant test method. Additional information is given in a supporting report (PFA 2013b) attached in Section 13.