Ohio Rev. Code § 4901.14
Any person who is a citizen of the United States who is a regular salaried employee of the person, firm, or corporation directly concerned, or a chamber of commerce in matters of a general character in which the majority of its members are directly concerned, and who manifests to the satisfaction of the public utilities commission that he possesses the necessary qualifications to enable him to render valuable service before the commission and that he is otherwise competent to advise and assist in the presentation of matters before the commission incident to the transportation of passengers or property and facilities pertaining thereto, shall be permitted to appear before the commission in the determination of transportation matters involving questions of fact only. Accredited representatives of organized labor may participate in hearings before the commission in matters relative to the enforcement of safety laws.
R.C. § 4901.14