By Donna Boyle Schwartz
Aluminum Foil
If you don’t know it by now, we’re here to tell you: Putting metal in a microwave is a huge no-no! Many microwaves are lined with metal, which acts like a mirror, bouncing microwaves around the box until they’re absorbed by the food. That’s great for heating food, but metal, unlike your leftovers, is a great conductor of electricity; it reflects heat rather than absorbing it, and that’s a big problem in a microwave. At best, a little metal in the microwave prevents food from cooking properly. At worst, the resulting heat will create sparks that could cause a fire and render your microwave unusable.
China with Metallic Accents
Fine china has no place in the microwave, especially if it is trimmed with metal accents like platinum or gold bands. Don’t forget: That lovely metallic trim is just that—metal. And when metal is microwaved it can result in sparks, fire, and ruined dinnerware. Before you pop cups and plates in the microwave, look for a message on the bottom of each dish stating that it’s microwave-safe. If your dish is not clearly marked as such, set it aside and reach for a glass or ceramic container that can take the heat.
Squeeze Bottles
A cold kitchen cupboard can cause honey to crystallize, which is cool if you’re conducting a science experiment, but a drag if you want to use the squeezable sweetener. While a short zap in the microwave can return crystallized honey to its liquid state, don’t try this with the honey still in the squeeze bottle! Most condiment containers, including squeeze bottles for honey, hot fudge, and mustard, are not microwave-safe. The soft plastic from which the bottles are made may melt, explode, or catch fire. If you want to microwave crystallized honey, scoop a little out into a microwave-safe container first. If you’d rather heat the entire bottle, dunk it in boiling water for a few seconds at a time until the honey liquefies.
Breast Milk
Busy new moms and working mothers have taken to freezing breast milk and thawing it as needed. The practice is perfectly safe, provided it’s done correctly (check with your doctor for guidelines). Microwaving frozen breast milk, on the other hand, is not a good idea. Microwaves heat milk unevenly, which creates “hot spots” in the milk that can scald the baby. Not only that, but some research has found that microwaving breast milk destroys immune-boosting proteins. The FDA suggests heating breast milk or formula under hot running tap water or in a pan of hot water that’s been removed from the stove burner. Before feeding, shake the bottle, and test the temperature of the milk on the back of your hand to ensure that it’s not too hot for baby to drink.
Eggs
It seems like there are hundreds of gadgets for sale in stores and online that promise to safely and easily cook eggs in the microwave, but you’d be wise not to waste your money. No matter which gizmo du jour you use, microwaving eggs is a fast track to a big mess. The rapid heat generated by microwaves creates steam inside the egg, which often causes it to explode. What’s worse than scrubbing egg yolk off the inside of your microwave? Having an egg explode on your plate—or even in your mouth when you bite into it. If you want a nice, warm egg, stick to the stovetop.
Styrofoam
When your morning coffee goes cold, it can be tempting to zap it in the microwave. But if that coffee is in a Styrofoam cup, back away from the microwave. Styrofoam, a soft, light plastic, melts when exposed to the high heat and rays of a microwave. When it melts, Styrofoam releases harmful chemicals into your food—so keep Styrofoam cups, bowls, and take-out containers out of your microwave. It’s important to note that Styrofoam is particularly bad for the environment, and most curbside recycling programs won’t accept the material for pickup. So, yes, pass on putting Styrofoam in the microwave, and while you’re at it, avoid bringing it home in the first place.
Paper Bags
Those convenient microwave popcorn bags may have given you the impression that it’s safe to heat paper bags. Not so! Not all paper bags are created equal. Popcorn bags are constructed of a material that contains susceptors that are designed to absorb the rays from the microwave and prevent the paper from catching fire. Paper lunch bags or grocery bags do not have these susceptors, which means they can be a hazard in the microwave.