The culprit? Organic spinach sold to Amy’s, Wegmans food stores, and three other organic brands, all which issued similar recalls. If you’re surprised that an angelic food like organic spinach could be the source of potentially fatal food poisoning, don’t be: Food recalls are on the rise among natural and organic produce—and subsequently, lots of healthy packaged products have made people deathly ill (thankfully, no reported illnesses have been traced yet to Amy’s or its spinach supplier). But the truth is, even the cleanest produce purveyors, including those mom-and-pop purveyors at your local farmer’s market, aren’t immune to contamination, say food safety experts. MORE: The Totally Disgusting Ways Food Gets Contaminated “Clean and natural are nice adjectives, but they don’t mean much when it comes to microbial food safety,” says Doug Powell, a food safety consultant and author of Barfblog. “Bacteria doesn’t discriminate.” In many ways, the recall shows how complicated the food manufacturing business has become, even for those with the best intentions. “To think there is a difference between Amy’s Kitchen and Wegmans when it comes to bacteria, there isn’t,” says Powell. “Listeria is pretty much everywhere. You will never eliminate it.” Listeria is a bacterium that lives in animals’ intestinal tracts, finding its way into our food supply many times when fruit and vegetable fields become contaminated with animal waste. It accounts for 20% of all food recalls, second only to salmonella, and unlike other bacteria, though, listeria thrives at cool temperatures and even stays viable when frozen. The only way to kill it is to cook it. What does this mean for the future of frozen dinners, which you inevitably cook to eat, anyway? If you really want to protect yourself, treat your microwaved meal like a roast: Use a digital thermometer and take several readers of its internal temp (emphasis on several because microwaves don’t cook food evenly) to make sure it reaches 165 degrees. It may seem strange to cook a frozen dinner like raw meat, but it’s the surest way to avoid listeria in microwaved food. MORE: When Eating Clean Kills You