If you’ve ever put something in the microwave and were horrified to see sparks start flying….you are not alone! I’m sure we all could probably share a microwave horror story or two. At the risk of embarrassing my youngest, Sten…we still tease him about the time he put “cup o’ noodles” in the microwave without any water and burned the heck out of our microwave! (Sorry Sten!)
Even though there are a myriad of great things we CAN make in the microwave (“cake in a mug” ring a bell?) there are still plenty of things we ought NOT be putting in them. Some of which might surprise you!
Did you know grapes could literally combust in the microwave? What about eggs? The fact is, if you’re not careful, your microwave could make you sick, expose you to harmful chemicals, or even start a fire!
Follow these tips to avoid dangerous microwave mistakes.
I’m totally guilty of using the microwave to defrost meat! The problem is that the thinner edges of the meat start to cook while the thicker middle stays frozen. That uneven distribution of heat can allow dangerous bacteria to grow.
If you do choose to defrost meat in the microwave, make sure you remove it from the foam trays and plastic wrap that it comes in at the grocery store. Those containers are not meant to be heated and can leach harmful chemicals into the meat.
A better alternative: leave your meats overnight in the fridge as the World Health Organization recommends.
Cooking Raw Eggs in Their Shells
When you microwave an egg, steam generates inside the shell. This can cause an explosion — ever tried scrubbing raw egg off of anything? You do not want to have to clean this up. Although people say they’ve hard boiled eggs plenty of times in the microwave with no problems, I would say proceed with caution.
Also be cautious when microwaving other foods that may explode. Anything in a tight skin, can explode because the water inside will expand when heated. Be sure to poke holes in things like hot dogs, potatoes, squash etc. before microwaving.
A better alternative: If you don’t want to risk exploding eggs in the microwave be sure to check out my favorite way for making perfect hard boiled eggs on the stove. If you want to heat up a peeled, hard boiled egg make sure you pierce it in multiple places so that there is a way for the steam to escape.
Heating Breast Milk
Microwaves do not heat things safely or evenly, especially for babies. Studies have shown that “hot spots” occur in breast milk when you heat it under microwave heat waves. These boiling hot pockets of liquid could burn your baby’s mouth. Plus, microwaving breast milk can destroy some of its immune-boosting proteins.
A better way alternative: 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.
Heating Up Leftovers In Plastic or Styrofoam
I think it’s pretty common knowledge now that many plastic products contain harmful chemicals that can leach into food when heated. But did you know that even products labeled “BPA-free” may contain other potentially harmful chemicals?
When you heat up plastic, it releases these chemicals. BPA’s and phthalates, for instance, have been linked to liver cancer, infertility, and genetic mutations in reproductive cells that can lead to genital deformities in offspring.
The same goes for Styrofoam. Not only will it melt in the microwave, when it melts, Styrofoam releases harmful chemicals into your food.
A better alternative: Take the extra minute or two and transfer your leftovers to a plate — for the sake of your children’s reproductive health.
Using Ceramic Dishes
Not all ceramic dishes are dangerous in the microwave but you don’t want to use anything that has been low fired. If a dish has been low fired it may have soaked up moisture into the clay body. That moisture can cause the dish to explode when heated in the microwave.
A better alternative: test whether or not a ceramic dish is microwave safe by carefully knocking on it with your knuckle. If you hear a clean ring, the dish is probably free of moisture. If it sounds dull, there is probably moisture in the clay. Use a different dish.
There is a phenomenon that can occur when heating a plain cup of water called superheating. If conditions are just right, bubbles won’t form in the water while heating, but as soon as you move the cup or pour anything else into the water, the heat is released and the water explodes. However, in most cases it is unlikely that superheating will occur. You would need to heat plain water for an extended period of time in a very clean, practically brand new, glass cup for superheating to happen. It’s also much more likely to occur with distilled water.
A better alternative: If you add something else to the water before heating, such as instant coffee or hot cocoa, it is much less likely that superheating will occur. If you want to be extra cautious when heating water, simply add a wooden spoon or stir stick to the cup in the microwave. You could also just take an extra five minutes to boil your water over the stove or invest in an electric kettle.
Heating/Reheating Grapes and Raisins
When you put grapes in the microwave you don’t get raisins! They will actually produce plasma. Although it might make for a fun experiment, I wouldn’t suggest trying it out at home. Raisins will actually smoke and can even catch on fire in the microwave.
While you’re probably not trying to warm your grapes before eating them, you might be cooking with raisins. They don’t explode, but they do generate quite a lot of smoke —probably not a substance you want to be eating.
A better alternative: to soften a batch of raisins to use in a raisin bread, cinnamon rolls, dessert sauce or any other recipe calling for raisins, place raisins in a microwave-safe bowl, cover with water and top with a lid. Microwave on high 30 to 45 seconds until the water is hot, then let the raisins steep in the water for 5 minutes. Drain.
Thinking “Microwave Safe” Dishes Are Safe
This may seem counterintuitive, but hear me out. The only thing the “microwave safe” label means is that the dish won’t melt or break when heated—but it doesn’t mean it is safe.
A better alternative: To reduce unnecessary risk, experts advise everyone to microwave food in glass or ceramic and replace plastic housewares labeled “microwave-safe” if they have been scratched or if the color has changed. If microwaving food in plastics is unavoidable, then pay attention to the recycling codes at the bottom of the container. Those codes say something about the type of plastic used. Safer choices are coded 1, 2, 4 and 5. Avoid 3, 6 and most plastics labeled 7.
Heating Food In The Packaging
You should only microwave food in its packaging if it is meant to be cooked in its package. If the packaging is microwave safe, be sure to discard it after cooking. Those types of packages are only meant to be heated one time. Even when packaging is meant to be microwaved, make sure it is vented in someway to prevent the package from exploding.
A better alternative: if the packaging isn’t specifically meant to be used in the microwave, transfer the contents of the package to a glass bowl before cooking.
I read a comment from someone on another website that said they once had to wash a pair of socks in a motel room. They decided to put the wet socks in the microwave to dry them out quickly. After the socks had been in the microwave for 3 minutes they caught on fire and started smoking. The elastic in the socks had sparked and set fire to the cotton material.
The microwave doesn’t suck water vapor out, the way a clothes dryer does. You’ll just end up with hot, wet clothes. Not only will it be HOT, it can also potentially damage or even ignite the fabric. This is especially true if the clothes are made out of synthetic material or have metal accents, such as buttons or zippers.
A better alternative: If you’re tempted to use the microwave because you need to dry clothes fast, a better option is to use your hair dryer. Lay the clothes out flat, turn the hair dryer up to the highest setting, and blow air on them until they’re dry.
Disinfecting Sponges Without Water
Refer to above tip about clothing. You can put a wet sponge in the microwave to disinfect but make sure to never put a dry sponge in the microwave. It can catch on fire!
A better alternative: be sure to soak sponges before using in microwave.
Cooking Hot Peppers
Like eggs, peppers can explode when heated too quickly in the microwave—and they can even catch on fire! The other problem with peppers is capsaicin, the chemical that makes them hot and spicy. When microwaves hit the pepper, capsaicin turns into an aerosol, resulting in a homemade pepper spray that can burn your eyes and skin the moment you open the appliance door.
A better alternative: If you’re cooking hot peppers, use the stovetop, oven, or broiler—and always handle with care.
Using Ordinary Brown Paper Bags
I had no idea there was a danger in microwaving brown paper bags! In fact, I use them to make microwave popcorn all the time. But according to the USDA, the ink, glue, and recycled materials in paper bags can emit toxic fumes when heated. Heat may also cause the bags to catch on fire.
Commercially-produced microwave 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.
A better alternative: a microwave-safe silicone popcorn bowl.
Using Any Dish with Hidden Metal
I think most of us know we shouldn’t put metal in the microwave. I actually didn’t know why until I wrote this post! Click here to a technical explanation. The basic explanation is that metal can damage the magnetron that runs the microwave and can even start a fire in extreme cases.
Be sure to watch out for dishes that may have any hidden metal on them! Some dishes are decorated with metallic paint that can be hazardous in the microwave. Also be on the lookout for takeout containers that have metal handles or foil linings.
A better alternative: before you put 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.
Running Your Microwave With Nothing In It
I have a feeling most of use would never intentionally run an empty microwave, but there are definitely times I thought I was turning on the microwave timer but actually turned on the microwave with nothing in it. When there is nothing to absorb the microwaves, the magnetron (the main element that makes the appliance operate) absorbs the microwaves instead. The microwaves can damage the magnetron and even start a fire.
A better alternative: Don’t do it.
Have you ever put something in the microwave that you shouldn’t have?