How often do you bring those takeout containers with leftover food to work? You may want to think twice before putting it in the microwave. Here's the bad news: by heating the plastic containers in the microwave, you could be releasing chemicals, from the pliable plastic, into your food. Even if the container OR plate is marked "microwave safe," doesn't mean it is. The label is stating that when heated, your bowl, plate or container, won't melt or break when heated.
TIP: The recycling codes can help. They're usually located at the bottom of the container. Avoid any that have the code 3 or 7. Do not reuse margarine tubs, take-out containers, whipped topping bowls, and other one-time use containers for re-heating food in the microwave. They are more likely to melt causing chemicals to seep into your food. For more information on the hazards of microwaving plastic, see the USDA's website here.