Mich. Comp. Laws § 445.571a

Sec. 1a. As used in section 1, "container composed of a combination of these materials" does not include a container that, when filled, is designed and intended to be frozen and is composed in whole or in part of aluminum and plastic or aluminum and paper in combination, if the aluminum content represents 20% or less of the unfilled container weight and the weight of the container materials represents 5% or less of the total weight of the filled container.