Mass. Gen. Laws ch. 94 § 2
The floors, walls and ceilings of each bakery, the equipment used in the handling or preparation of bakery products or the ingredients thereof, and the wagons, boxes, baskets and other receptacles in which such products are transported, shall at all times be kept by the owner or operator of the bakery or by the distributor of such products in a clean and sanitary condition and free from dirt and dust, flies, insects and other contaminating matter. All show cases, shelves and other places where bakery products are sold shall at all times be kept by the dealer well covered, properly ventilated, adequately protected from dirt and dust, flies, insects and other contaminating matter, and in a sweet, clean and sanitary condition. Shipping baskets and other containers for transporting bakery products shall be kept clean and, whenever the property of a distributor or dealer, shall not be used for the shipment of other products to any person or concern.
Mass. Gen. Laws ch. 94, § 2