Ohio Revised Code Title I. State Government § 119.02

Every agency authorized by law to adopt, amend, or rescind rules shall comply with the procedure prescribed in sections 119.01 to 119.13, inclusive, of the Revised Code, for the adoption, amendment, or rescission of rules. Unless otherwise specifically provided by law, the failure of any agency to comply with such procedure shall invalidate any rule or amendment adopted, or the rescission of any rule.