When you put foods into a microwave, you should find out if it is safe or not. Here are foods you should NOT microwave.
1. Frozen fruits
When you microwave frozen fruits, its texture changes a lot. It is always recommended to defrost fruits in refrigerator or at room temperature. According to researches, some fruits generates harmful substances when it is microwaved.
2. Breast Milk
Breast milk contains various nutrients and antibacterial material for babies. When it is microwaved, those nutrients considerably decreases. It unevenly warms when it is microwaved, and the bottle may also generate harmful materials. Since breast milk is for babies, you should store it very carefully.
It is also a bad idea to put meat in microwave. Edge of the cut of meat gets cooked while middle part remains frozen. Microwaved meats may also lost vitamin B, and the warm (but not cooked) part of the meat allows bacteria to grow. Best way to defrost meat is to put in room temperature.
4. Plastic container
It is known that plastic containers are harmful when it is microwaved. It generates many harmful chemicals including BPA when it is microwaved. Always use microwave-safe containers!
5. Paper and aluminum foil
Microwaving aluminum foil is very dangerous because it almost always catches fire-and this is well known fact. However, some people neglect dangerousness of paper (paper bag, paper wrap, etc) in microwave. Paper also catches fire when microwaved, and I have experience that when I was young. So, be careful!
When you microwave something, always ask and search if it is safe!