December 18, 2000
Is it safe to microwave Styrofoam? My roommate is always eating those ramen cup of noodle soups. She doesn't follow the directions and just puts the whole thing in the microwave.
Lita
Dear Lita,
Not to worry. Yes, it is safe to put Styrofoam in the microwave. The only concern would be if your roommate cooked her soup so long that the soup got so hot that it melts the Styrofoam, but it doesn't sound to me like that is happening.
When you use your microwave, you are not heating the cooking utensil like you do in conventional cooking. You are only heating the food. The microwaves actually penetrates the food, passing straight through the surrounding air and cooking utensil, which saves cooking time and electricity. The microwaves themselves are not hot, but are attracted and absorbed by water, fat and sugar in the food.
The microwaves cause the water, sugar or fat molecules in the food to rotate rapidly (at the rate of 5 billion times per second). They bump into each other, causing friction, and it is this heat which actually cooks the food. Sort of like when you rub your hands together -- feel how warm they get.
So, you see the only thing that gets hot when you cook in the microwave is the food. Sometimes the cooking utensil will get hot, but that is not from the cooking, it is from the heat generated by the food. If the food gets hot enough, it could make the utensil hot. The only utensils not safe to use in the microwave are metal and those containing lead.
Most glass and ceramic dishes are safe for the microwave, but if you have your doubts, here is a simple way to test the dish. Place a cup full of water and the dish in question in your microwave. Cook at 100% power for one minute. If the water gets hot and the dish remains cool, it is safe to use in the microwave.
If the dish is hot that means the microwaves were attracted to lead or other substance in the dish, and it is not safe to use in your microwave. Metal reflects the microwaves rather than letting them get into the dish to the food. You should also avoid cookware that has metallic trim on it. Microwave energy can become trapped in the trim and cause arching (sparks that can start a fire).
I hope this answers your question.
(Note: Thank you to Mister Microwave's How a Microwave Oven Cooks. Much of this answer was paraphrased from information found at this web pages.)
December 21, 2000
Thank you very much for answering my question. I feel a lot better knowing that Styrofoam is safe, and also knowing that's it's not OK to stick just any dish in the microwave (like I had been doing)! The tip on how to make sure a dish is microwave safe was very helpful.
Thanks again.
Lita