The Office of the State Fire Marshal has power to make, adopt and enforce rules and regulations governing the storing, transporting as cargo, selling, dispensing or use of liquefied petroleum gases for purposes other than as a propellant fuel in school buses, except as otherwise regulated by the Illinois Department of Transportation under the provisions of the “Illinois Hazardous Materials Transportation Act”, approved August 26, 1977, as amended. Rules and regulations adopted under this Section shall be in substantial conformity with the generally accepted standards of safety concerning the same subject matter. Rules and regulations in substantial conformity with the published Standards of the National Fire Protection Association for the Storage and Handling of Liquefied Petroleum Gases and with the published Recommended Good Practice Rules for Liquefied Petroleum Gas Piping and Appliance Installations in Buildings as recommended by the National Fire Protection Association, shall be considered in substantial conformity with the generally accepted standards of safety. No municipality or other political subdivision shall enforce any ordinance or regulation in conflict with this Act or with the regulations promulgated under this Section, except in the location and operation of liquefied petroleum gas bulk plants and storage systems of over 1200 gallon capacity.