# How toxic is disilanol?

Silicon has been known to form analogues of organic compounds. For example, silicon with 4 hydrogen atoms forms silane as opposed to methane. This continues up the alkane list, with disilane for ethane, and so forth.

Silanes also have with hydroxyl groups to form "silanol." Thus, disilanol is the silicon analogue of ethanol. ($\ce{H3Si-SiH2OH}$)

How toxic is disilanol?

Difficult to say. After a fair amount of Googling, I was unable to find any reliable sources on the compound you ask about, $\ce{H3Si-SiH2OH}$. From the Wikipedia article on silanols, it appears that the simple silanols are not stable, but no reference is provided.
It stands to reason that if $\ce{H3SiOH}$ is not stable, there is a good chance that $\ce{H3Si-SiH2OH}$ is also not very stable. Disiloxane $\ce{H3Si-O-SiH3}$ is much more stable, and silanols likely convert into siloxanes.