Packaged salad greens make for a quick, healthy lunch—and if they're labeled "ready to eat," you can save yourself even more time by not rinsing the leaves, says Don Schaffner, PhD, a professor of food science at Rutgers University. Ready-to-eat greens undergo a thorough commercial-grade cleaning to kill germs. And according to a review in the journal Food Protection Trends, washing at home is more likely to introduce bacteria (like E. coli) than clean away any contaminants that might have made it through the packaging process.
Why? Because poor food-handling practices may expose your salad to germs lingering in your kitchen. More than a fifth of Americans admit that they don't always wash their hands before preparing food, and 10 percent don't use soap or disinfectant on surfaces that have come in contact with raw meat. Bottom line: "This is one case where DIY isn't better," says Schaffner. "If it comes out of a bag or a plastic box, I don't wash it."