Mich. Comp. Laws § 445.591

Sec. 1. As used in this act: (a) "Auxiliary container" means a bag, cup, bottle, or other packaging, whether reusable or single-use, that meets both of the following requirements: (i) Is made of cloth, paper, plastic, cardboard, corrugated material, aluminum, glass, postconsumer recycled material, or similar material or substrates, including coated, laminated, or multilayer substrates. (ii) Is designed for transporting, consuming, or protecting merchandise, food, or beverages from or at a food service or retail facility. (b) "Local unit of government" means a county, township, city, or village.