Ohio Rev. Code Ann. § 3741.14
(B) The fire marshal shall adopt, as part of the state fire code, rules governing the equipment, operation, and maintenance of filling stations. The rules shall be such as are necessary for the protection of the persons and property of the public, but shall require as a minimum that:
(4) A sign bearing the following words in block letters be conspicuously posted on each gasoline pump island where self-service is offered: