Whether you re loyal to a particular brand (think Tupperware or OXO) or a certain material (plastic, glass, or stainless steel), food storage containers are kitchen essentials. They re just the thing for storing leftovers or components of a make-ahead meal, but they can also do double duty, serving as a container to transport lunch or snacks when you re on the go. And it s important to clean them properly if you want to ensure their longevity some types can last years, not months, if you know how to maintain them. Ahead, we re sharing the difference between three common materials, how to properly care for food storage containers, and signs that it s time to replace yours.