Mo. Rev. Stat. § 319.342
3. Any municipality or county may by ordinance or order:
5. Any authorized representative of a municipality, county or an appropriate fire protection official may:
6. Except for any ordinance or order of any county with a charter form of government and with more than one million inhabitants, no provision of a municipal ordinance or county ordinance or order in effect on August 28, 2007, or which may be adopted at a future date by a city or county may preempt, amend, exceed, or conflict with the provisions of sections 319.300 to 319.342 nor any rule promulgated by the state fire marshal under section 319.327. Neither shall any existing or future municipal ordinance or county ordinance or order preempt, amend, exceed, or conflict with the provisions of any statute, regulation, or policy established by:
(L. 2007 H.B. 298)