What is really in your frozen meal containers?
We've all seen it, the promise of Bisphenol-A (BPA) free packaging. The two words "microwave-safe" written in like size 40 font on your frozen meal. But, the truth of the matter is; plastics are really difficult to regulate. This is because the Food and Drug Administration (FDA) has pretty lax rules for regulating chemicals added in plastic. Basically, as long as the plastic contains less than a certain percent of a chemical, it can be declared as "free" of that specific chemical, even if a product is not (1). For the most part, we are mainly concerned about BPA and phthalates. BPA is added to plastics to make the plastic harder and clearer, while phthalates are added to increase a plastics flexibility (think plastic wrap). Either one, getting into your food and being ingested, is not good for you. Both BPA and phthalates have been shown to be endocrine disruptors, essentially messing up how the hormones in your body should work, among other negative health effects (2). Even worse, BPA and phthalates can more easily get into your food when plastics are heated, which happens when you microwave your frozen meal straight from the package.
But what about my fancy organic meals in cardboard containers?
We hate to burst your bubble, but even those cardboard containers that definitely aren't made of plastic and promised to be BPA free are still not the safest. Although most packaging in microwavable frozen meals no longer contain large amounts of BPA or phthalates, they have likely been replaced with other chemicals that have similar properties and therefore, similar health effects. Depending on brand, many of these cardboard containers are PET-lined to prevent the food from leaking from the container. If you've heard about PET before, it's most likely because it's mainly used for milk jugs or storage of cold items. However, PET is definitely not safe when heated and neither is the polypropylene plastic film on top sealing in the food (3). Polypropylene is made of what we call plastic #5, which even though is considered safe and heat-resistant, is still a form of plastic and warrants concern (a.k.a. it probably shouldn't be heated in the microwave) (3).
Does this mean I have to give up my frozen meals?
Absolutely not! We aren't trying to starve over here. But, there are a bunch of easy, safer ways to heat up your breakfast, lunch or dinner. Here are some general tips. If your food has to be covered in the microwave, use a damp paper towel or kitchen towel, not plastic wrap, which likely contains phthalates. In addition to the plastic wrap itself releasing harmful gases, condensation underneath the plastic wrap, which absorbs phthalates from the heated plastic wrap, could drip down into your food (2).
Did you know, most frozen meals are super easy to pop out of the plastic tray - just like a giant ice cube. Then, you can place your meal in a microwave safe container and warm according to the instructions on the package. If you're taking your frozen meal for lunch and you want to save a little bit of time, what I like to do is pop the frozen meal into a microwave safe container (check out some good ones here!) the night before, then pop it back in the freezer, so it'll be ready to go in the morning for taking to work. It's so great because I don't have to worry about remembering to pack a microwave safe-container. Easy peasy!
The bottom line is, since we don't know exactly what manufacturers use to make each type of plastic, it is best to just assume that the plastic packaging on frozen meals likely has at least some negative health effects if microwaved. So, take the extra 30 seconds to remove the meal from that tray and microwave it in either a glass container or microwave-safe dish. Then, dig in and eat that lasagna to your heart's content!
2. http://time.com/4229503/plastic-in-microwave-is-it-safe/3. http://www.nontoxicrevolution.org/blog/7-types-of-plastic