Ohio Rev. Code § 3307.09: Quorum.

A majority of the members of the state teachers retirement board constitutes a quorum for the transaction of any business. All meetings of the board shall be open to the public except executive sessions as set forth in division (G) of section 121.22 of the Revised Code, and any portions of any sessions discussing medical records or the degree of disability of a member excluded from public inspection by section 3307.20 of the Revised Code.