410 ILCS 1/20

With respect to retail containers containing less than 55 gallons of engine coolant or antifreeze, no local government, municipality, or other political subdivision of this State shall have any authority either to establish or continue in effect any prohibition, limitation, standard, or other requirement relating to the inclusion of a bittering agent in engine coolant or antifreeze that is in any way different from, or in addition to, the provisions of this Act. This Section is a denial and limitation of home rule powers and functions under subsection (h) of Section 6 of Article VII of the Illinois Constitution.