Ohio Revised Code Title III. Counties § 307.90

(A) The award of all contracts subject to sections 307.86 to 307.92 of the Revised Code shall be made to the lowest and best bidder. The bond or bid guaranty of all unsuccessful bidders shall be returned to them by the contracting authority immediately upon awarding the contract or rejection of all bids. The contracting authority may reject all bids.

(B) With respect to any contract for the purchase of equipment, materials, supplies, insurance, services, or a public improvement into which a county or its officers may enter, a board of county commissioners, by resolution, may adopt the model system of preferences for products mined or produced in Ohio and the United States and for Ohio-based contractors promulgated pursuant to division (E) of section 125.11 of the Revised Code. The resolution shall specify the class or classes of contracts to which the system of preferences apply, and once adopted, operates to modify the awarding of such contracts accordingly. While the system of preferences is in effect, no county officer or employee with the responsibility for doing so shall award a contract to which the system applies in violation of the preference system.