Michigan Compiled Laws, Chapter 324. Natural Resources and Environmental Protection § 324.8508

Sec. 8508. (1) This part does not require the payment of inspection fees for sales or exchanges of fertilizers or soil conditioners between manufacturers who mix fertilizer or soil conditioner materials for sale, or prevent the free and unrestricted shipment of fertilizers or soil conditioners for further processing to manufacturers licensed under this part.

(2) This part does not apply to a carrier in respect to a fertilizer or soil conditioner delivered or consigned to it by others for transportation in the ordinary course of its business as a carrier.