Is that chicken breast at the bottom of your freezer still safe to eat? How about the mustard that’s been in your cupboard for who knows how long? It’s sometimes hard to know when food needs to be tossed, or when it’s perfectly safe to salvage. We've de-mystified the process with this handy chart, which incorporates advice from the USDA, food scientists, and food manufacturers. (Scroll down for downloadable versions that are perfect for hanging on the fridge).