Indiana Code Title 9. Motor Vehicles § 9-19-2-1

Sec. 1. Air conditioning equipment shall be manufactured, installed, and maintained with due regard for the safety of the occupants of the vehicle and the public and may not contain a refrigerant that is toxic to individuals or that is flammable, unless the refrigerant is included in the list published by the United States Environmental Protection Agency as a safe alternative motor vehicle air conditioning substitute for chlorofluorocarbon-12 under 42 U.S.C. 7671k(c).