Even if your food containers are labeled as one of the safe plastics, always transfer food to a glass or china dish before reheating in the microwave. All plastics contain possible harmful chemicals, and when heated, those chemicals can leech onto the food that is next to them. Take-out containers are one of the worst culprits when it comes to plastics that contain toxic elements, so never reheat food in those containers.
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If you're using food storage containers that are made from safe plastics, no need to do a total kitchen overhaul and throw all of your plastic away. It is a good idea, however, to start making a gradual shift over to glass containers. There are a lot of high quality and affordable options out there. The best are those that are made completely of glass, including the lids. When taking food on the go, try glass containers that have snug fitting plastic lids -- that are BPA and PVC-free, of course.
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Dishwashers use very hot water and steam to clean dishes thoroughly -- which leaves us with sparkling plates and glasses -- but can unfortunately pose a problem when it comes to plastics. Just like microwaving, heating plastic can release harmful chemicals, so play it safe and wash your plastic containers by hand in lukewarm water.
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Flip over your food storage containers and take a look at the small number printed on the bottom. If the recycling number is #3 or #7, it likely contains either BPA (bisphenol A) or phthalates (used to make PVC plastics) which mimic estrogen and can interfere with hormone levels. These can be especially harmful for still-developing bodies so, unless the container clearly states that it is BPA and PVC-free, the safest thing to do is to get rid of them. Canada and the European Union have already banned BPA use in baby bottles and many people, including me, are not going to wait around for the U.S. to follow suit. If you don't want to part with your plastics completely, be sure that your containers are either #2, #4 or #5, which are widely considered safe for food storage.
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