Ohio Revised Code Title VII. Municipal Corporations § 717.21

With respect to any contract for the purchase of equipment, materials, supplies, insurance, services, or a public improvement into which a municipality or its officers may enter, the legislative authority of the municipality, by ordinance, 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 ordinance 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 municipal officer or employee with the responsibility for doing so shall award a contract to which the system applies in violation of the preference system.