No motor vehicle operated on any highway shall be equipped with any air conditioning unit unless such device is of a type approved as to safety by the Superintendent. The Superintendent is authorized to promulgate regulations setting specifications relating to the design, construction, installation, maintenance, and use of such air conditioning units. No refrigerant used in such unit shall be explosive, flammable, or toxic, 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 chloroflourocarbon-12, pursuant to 42 U.S.C. 7671 k (c).