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!
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 always 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.
You also want to avoid ever cooking stuffed meat in the microwave because it is difficult to get the insides to cook completely.
Raw Eggs in Their Shells or Peeled Hard Boiled Eggs
When microwaving an egg pressure builds up and can cause it to explode. Although people say they’ve hard boiled eggs plenty of times in the microwave with no problems. So I would say proceed with caution.
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. 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.
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.
Microwaving breast milk can destroy some of its immune-boosting proteins. Liquids also heat unevenly in the microwave which can lead to hot spots in the milk that may burn babies mouths.
Plastic and 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 harmful chemicals?
The Environmental Working Group advises against using any type of plastic container in the microwave. You’ll want to especially avoid microwaving one-time use storage containers, old, cracked containers, take-out containers, and food containers not meant to be heated (butter tubs, yogurt containers, sour cream containers etc). And never, ever use any kind of container not meant for food!
It is generally considered safe to use plastic wrap in the microwave but make sure it doesn’t directly touch food.
Finally avoid reheating especially fatty foods in plastic. The fat causes the food to absorb more of the harmful chemicals.
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 simple way to test whether or not a ceramic dish is microwave safe is to carefully knock 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.
Plain Cups of Water
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.
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.
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.
“Microwave Safe” Dishes
This may seem counterintuitive, but hear me out. Apparently, the only thing the “microwave safe” label means is that the microwave won’t damage the dish and vice versa. But the FDA doesn’t requite manufacturers to test the safety of dishes after heating. Additionally, the “microwave safe” label doesn’t mean that no harmful chemicals will leach out when the dish is heated.
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.
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. I don’t necessarily think that would happen with every type of clothing, but I would rather be safe than sorry. Microwaves were not meant to act as clothes dryers.
The capsaicin in hot peppers can actually catch on fire! Even if the capsaicin doesn’t catch on fire the microwave releases the chemical into the air. Inhaling the vapor can burn your eyes and throat.
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!
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. 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.
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. Some take out containers have metal handles or foil linings that aren’t microwave safe.
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 absorbes the microwaves instead. The microwaves can damage the magnetron and even start a fire.
Have you ever put something in the microwave that you shouldn’t have?