A Bad Wrap?
There's nothing more convenient than reheating leftovers in the microwave -- especially when you just can take the plastic container straight from the fridge to the microwave. But if you're concerned about your health, you may want to take an additional step and remove the food from the plastic and place it in a microwave-safe glass container to avoid exposure to chemicals. According to Rolf Halden, PhD, PE, at the Johns Hopkins Bloomberg School of Public Health, it's not dioxins -- chemical compounds formed during waste incineration and certain chemical manufacturing processes that are thought to contribute to a variety of health problems, including an increased risk of cancer -- that create the danger in plastic (as many people think), it's plasticizers -- chemicals that give plastic its flexibility -- that pose the greatest problem. Studies show that when food contained in plastic made with plasticizers is subjected to high heat, toxic chemicals can migrate into foods. Some plasticizers emit hormone-mimicking substances called endocrine disrupters, which scientists are studying for their link to birth defects, fertility problems and cancer. Two leading companies marketing plastic wraps for home use say on their Web sites that their products pose no health threats since they're made from polyethylene -- a widely used plastic shown to be nontoxic and inert (meaning chemicals can't migrate) -- and contain no plasticizers. But there are different kinds of plastics -- and not all of them are safe to use in the microwave. Your best bet, says Dr. Halden, is to read labels, follow the manufacturer's directions and use products only for the use for which they're intended. In other words, don't microwave leftovers in a sandwich bag, an old margarine tub, your toddler's plastic dinnerware or a takeout container. If you buy frozen dinners in microwaveable trays, don't reuse the trays -- they were designed for one-time use only. Dr. Halden refers consumers to the USDA Food Safety and Inspection Service site(http://www.fsis.usda.gov/factsheets/cooking_ safely_in_the_microwave/index.asp), that says you can use microwave plastic wraps, wax paper, cooking bags, parchment paper and white microwave-safe paper towels -- but make sure plastic wrap doesn't touch food during microwaving, since the plastic can heat up and melt. Safest: Use glass or plastic products and cookware that is specifically manufactured for microwave oven use. According to Dr. Halden, we need more research to get definitive answers about the safety of plastic products for all food uses. Until then, you may have greater peace of mind if you use heat-resistant glass containers with lids (or waxed paper) instead of plastic wraps and containers for heating your food.