Do Not Heat Plastic Food Containers

Lunch at your desk can be a downer, especially when it involves leftovers reheated in the office microwave. But are you putting more into your body than just lukewarm pad thai?

Since plastic was first synthesized in the early 1900s, it has evolved into everything from lifesaving medical devices to a softening agent in hair conditioner. Plastic is ubiquitous but there are two chemicals in it to watch out for when it comes to what your body ingests.

Phthalates, the chemicals that make a PVC container flexible, can migrate out of the plastic when it's heated. Phthalates can leach into food, resulting in hormone imbalances and birth defects, although no one knows at what level those effects are triggered. Phthalates are present in measurable levels in the blood of nearly every person in the developed world.

Bisphenol A, or BPA, is a potentially worse offender. Once tested for possible use as an estrogen replacement, BPA was found to be of better use in the mass production of polycarbonate plastic. It's used in everything from the lining of metal soup cans to receipt paper.

While the recycling numbers at the bottom of plastic items are not meant to provide health information or risks, they can sometimes provide clues to the chemicals in them.

The amount of chemicals leaching into food depends on the type of plastic that is put in the microwave, the time it is heated and the physical condition of the container. Cracked containers and those that have been washed hundreds of times often give off more toxins when heated. Any deformities or discoloration are a sign it's time for the recycling bin.

And reheating foods heavy in cream and butter in plastic is always a bad idea. As fatty foods absorb more of these harmful chemicals when heated.

Rather than torturing yourself over what plastic is safe, in fact, it’s better to use an inert container such as glass or ceramic to heat your food. Along with cold spots in food that could harbor bacteria, food tastes much better if it is prepared in a hot oven or on the stove, and not cold on the inside and too hot on the outside.  For more information and more helpful articles visit .