430 ILCS 50/5.11: Units of local government; hazard signage systems.

(a) A unit of local government may adopt ordinances or regulations requiring a hazard signage system applicable to equipment, facilities, structures, or locations involved in the use, storage, or manufacture of hazardous materials. The hazard signage system (such as, but not limited to, the National Fire Protection Association standard "NFPA 704" system as specified in its Standard System for the Identification of the Fire Hazards of Materials for Emergency Response) shall be consistent with any such signage required by federal law or regulation.

(b) An ordinance or regulation adopted by a unit of local government under this Section requiring a hazard signage system may not take effect sooner than 90 days after its adoption by the unit of local government.

(c) A home rule unit may not regulate hazard signage systems in a manner inconsistent with the regulation of those systems by the State under this Act or by the federal government. This Section is a limitation under subsection (i) of Section 6 of Article VII of the Illinois Constitution on the concurrent exercise by home rule units of powers and functions exercised by the State.