Ohio Rev. Code § 4973.04: Companies prohibited from demanding or receiving waivers.

No railroad company, insurance society or association, or other person shall demand, accept, or enter into an agreement or stipulation with a person in or about to enter the employ of a railroad company whereby he stipulates or agrees to surrender or waive any right to damages against a railroad company thereafter arising for personal injury or death, or whereby he agrees to surrender or waive, in case he asserts such right, any other right.