Seeing reusable shopping bags at the grocery store or farmers market has become the norm. But as more of us reuse and reuse the bags, it's important to make sure the bags that carry food home stay clean and healthy. Washing reusable bags helps prevent things like yeast and bacteria from growing inside and cross-contaminating your food. Ripstop nylon bags are the ideal choice; they can be washed in hot water, and if they get a tear, the hole will literally heal itself and stop ripping. Choose different-colored nylon bags to separate seafood, meat and produce.