Ohio Rev. Code Ann. § 135.18
(A) Each institution designated as a public depository and awarded public deposits under sections 135.01 to 135.21 of the Revised Code, except as provided in section 135.144 or 135.145 of the Revised Code, shall provide security for the repayment of all public deposits by selecting one of the following methods:
(D) The following securities or other obligations shall be eligible for the purposes of this section:
(H) When the public depository has placed eligible securities described in divisions (D)(2) to (9) of this section with a trustee for safekeeping, the public depository may at any time substitute or exchange eligible securities having a current market value equal to or greater than the current market value of the securities then on deposit and for which they are to be substituted or exchanged without specific authorization of any public depositor's governing board, boards, or treasurer of any such substitution or exchange only if one of the following applies: