Ohio Rev. Code § 749.30: Bids shall be sealed.

Each bid submitted under section 749.28 of the Revised Code shall be enclosed in a sealed envelope and deposited with the clerk of the board of hospital trustees, and such envelope shall have indorsed thereon the nature of the bid. All bids shall be opened at the time, date, and place specified in the notice to bidders or specifications. The time, date, and place of bid openings may be extended to a later date by the board of hospital trustees, provided that written or oral notice of the change shall be given to all persons who have received or requested specifications no later than ninety-six hours prior to the original time and date fixed for the opening.