Ohio Rev. Code Ann. § 9.60
(A) As used in this section:
(D)
(G)
(1) The office of the state fire marshal, when providing services pursuant to this section, is liable for injury, death, or loss to person or property caused by the negligent operation of any motor vehicle by its employees upon the public roads, highways, or streets in the state when the employees are engaged within the scope of their employment and authority, without regard to the proximity of, that operation to the office of the state fire marshal. Notwithstanding division (A)(1) of section 2743.02 of the Revised Code, the following are full defenses to that liability:
(2) An employee of the office of the state fire marshal, when providing services pursuant to this section, is immune from liability for injury, death, or loss to person or property caused by the operation of any motor vehicle upon the public roads, highways, or streets in the state, without regard to the proximity of that operation to the office of the state fire marshal, unless one of the following applies: