415 ILCS 15/10
Beginning January 1, 1992, no person shall offer for sale any single use plastic bottle with a capacity of 16 fluid ounces or more, nor any other single use rigid plastic container with a capacity of 8 fluid ounces or more, that is not coded in a manner that assists recyclers in sorting such containers by resin composition. The code shall consist of a 3-sided triangular arrow with a number in the center and letters underneath. The number and letters shall indicate the resin from which the container is made as follows: 1 and PETE for polyethylene terephthalate, 2 and HDPE for high density polyethylene, 3 and V for vinyl, 4 and LDPE for low density polyethylene, 5 and PP for polypropylene, 6 and PS for polystyrene, and 7 and Other for other materials, including multi-layer materials. Containers with labels or base cups of different material shall be coded by their primary, basic material. However, this Section does not apply to the plastic casings on lead-acid storage batteries.
415 ILCS 15/10