You might want to smell that milk before you toss it out. It may be past its expiration date, but that doesn't mean it's bad. A new study by Harvard Law School's Food Law and Policy Clinic and the Natural Resources Defense Council finds that expiration dates have little to do with a food's edibility, and that a lot of food is wasted because of conservative expiration dates. "The dates are undefined in law and have nothing to do with safety," said the study's lead author, Emily Broad Leib. "[Manufacturers are] picking dates that are really protective over their brand, which is fine. It's just important for consumers to know that." The study pushes for more standardized expiration dates, to cut down on the 160 billion tons of food that are wasted every year.