When shopping at the grocery store, how you pack your reusable shopping bags can help you avoid cross contamination. Separate your purchases into four categories: frozen and perishable, like fruits and vegetables; meat and poultry products; fragile items, like eggs and bread; and nonedible items, like cleaning supplies and cosmetics. Designate specific bags for items in these categories. Keeping frozen items with perishables has a double-duty purpose: The frozen food acts as an ice pack to keep the fresh veggies chilled. Using color-coded reusable bags for category purposes is a simple way to keep everything healthy and free of cross contamination when you shop.