Ohio Rev. Code § 4113.07
In all actions, described in section 4113.03 of the Revised Code, the fact that the employee may have been guilty of contributory negligence shall not bar a recovery where his contributory negligence is slight and the negligence of the employer is gross in comparison, but the damages shall be diminished by the jury in proportion to the amount of negligence attributable to such employee. No employee who is injured or killed shall be held in any degree to have been guilty of contributory negligence in any case where the violation by such employer of any law of this state or of the United States enacted for the safety of employees in any way contributed to the injury or death of such employee unless by the terms of his employment it was expressly made the duty of such employee to report such violation to the employer and the evidence shows that such employee failed to report and that the employer was not possessed of knowledge of such violation. All questions of negligence, contributory negligence, and assumption of risk are for the jury, under the instruction of the court.
R.C. §4113.07