Oh. Const. art. II, § 37
Ohio Const. art. II, § 37. Workday and workweek on public projects
Except in cases of extraordinary emergency, not to exceed eight hours shall constitute a day's work, and not to exceed forty-eight hours a week's work, for workmen engaged on any public work carried on or aided by the state, or any political sub-division thereof, whether done by contract, or otherwise. Effective: January 1, 1913