15 Surprising Microwave Dangers And How To Avoid Them

There’s no denying that the microwave is a useful and highly convenient appliance, but there are certain things you need to be aware of to use one safely. Just ask my youngest son Sten, who, as a young child, started microwaving some Cup Noodles without adding water first.

It mostly produced an impressive amount of smoke, along with an aroma of burnt noodles and styrofoam that lingered in our kitchen for several days. (No real harm was done though and we always get a good laugh out of remembering that incident!)

But not all microwave mishaps are as harmless as Sten’s (thankfully) was—more hazardous outcomes include explosions, leaching chemicals, and unsafe food. But the good news about these undesirable outcomes is that all of them are entirely avoidable.

Today I’ll be sharing 15 different behaviors to avoid when it comes to using your microwave (that’s on top of “microwaving Cup Noodles without water,” which was a freebie). ;-) I’ll tell you why each behavior is potentially dangerous and offer safe alternatives, so that hopefully we can all avoid microwave mishaps in the future.

15 Things You Should NOT Do With Your Microwave

1. Defrost Meat

The problem with defrosting meat in your microwave is that the heat often gets distributed through the meat unevenly. The edges of your meat are likely to start cooking before the center even begins defrosting, which can lead to bacterial growth that can make someone sick.

Safer Alternative: The USDA recommends either thawing food overnight in your refrigerator or cooking it directly from frozen.

2. Cook Eggs In The Shell

Microwaving anything with a tight skin or shell (like eggs, hot dogs, squash, etc.) can be a risky business. The problem is that as the moisture inside them heats up, steam will start to build up. The steam can create pressure, which can build to the point where the food “explodes,” which is definitely not a mess you want to clean up!

Safer Alternative: You’re better off cooking whole eggs in a a pot of boiling water, or in your Instant Pot. You can still heat up peeled hard-boiled eggs in your microwave, but just make sure to prick them on all sides with a fork to allow steam to escape.

Related: 11 Surprising Ways Your Microwave Is More Useful Than You Think

3. Warm Up Breast Milk

The problem with using your microwave to heat up breast milk is the same as with frozen meat: the potential for uneven heating. Hot spots may develop in the milk when microwaved, which could easily burn a baby’s mouth.

Safer Alternative: The FDA suggests heating breast milk either by running it under hot water, or by heating water on your stovetop, removing the pan from heat, then placing the bottle inside. You should still swirl or stir the milk to make sure it is a uniform temperature throughout, and test the temperature by putting a bit of the milk onto the back of your hand. (It should feel lukewarm, not hot.)

4. Heat Leftovers In Carryout Containers

It’s widely known that certain plastic products contain chemicals like BPA that can leach into food when heated. The effect of these chemicals is still being studied, but animal studies have shown that exposure to high levels of these chemicals can have a toxic effect. So tossing your takeout container into the microwave may not be the best idea.

Safer Alternative: Look at the labeling on the container itself, and if it doesn’t say “microwave-safe,” transfer the food to a glass container or a microwave-safe plate.

5. Use Ceramic Dishes

While many ceramic dishes are perfectly safe to use in your microwave, not all of them are. For instance, “low fired” ceramics retain some of the porous nature of clay, meaning they can soak up moisture. That becomes problematic in a microwave, where that moisture can heat up and cause the ceramic to shatter.

Safe Alternative: Make sure to check your ceramic dishes for a “microwave-safe” label. When in doubt, use a different dish. (Oven-safe Pyrex glass is always a safe bet!)

Related: How to Clean Pyrex Dishes

6. Boil Water

You may have already heard about the hazards of “superheated” water, which can occur when very clean water is heated in a microwave inside a very clean cup. Superheated water doesn’t show any signs of boiling, but will release its stored heat (ie. explode) when disturbed or moved. Your chances of accidentally superheating water are low, but it’s more likely if distilled water is used.

Safer Alternative: If you’re concerned about the possibility of superheating, put a wooden spoon or a wood stir stick in the container along with the water to prevent the phenomenon. Or you can always just boil your water in a kettle instead.

7. Heat Raisins

Some recipes call for raisins to be softened before using them, but throwing a bunch of raisins into your microwave is not the way to do it! Raisins will smoke in your microwave, and could even catch fire.

Safer Alternative: Here’s how to safely use your microwave to soften raisins. Put the raisins in a microwave-safe bowl and cover them with water. Place a microwave-safe plate or lid on top, and heat the bowl of raisins for about 30-45 seconds. Let the raisins steep in the hot water for 5 minutes, then drain and use.

8. Think “Microwave-Safe” Means “Risk-Free”

The only thing that a “microwave-safe” label means is that a dish won’t melt, break, or produce large amounts of unsafe fumes or chemicals when microwaved, but any microwave-safe dish can be compromised. Scratches and changes in color can be indicators that a dish or container should be replaced.

Safer Alternative: To reduce unnecessary risk, stick to using glass containers and high-fired ceramics in your microwave.

9. Heat Packaged Food

The only time you should microwave food that’s still in its original packaging is if the package clearly instructs you to do so. And even then, the packaging should be thrown away after microwaving, because they’re typically only meant to be cooked once.

Safer Alternative: If the packaging isn’t meant to go in the microwave, transfer the food to a microwave-safe plate or bowl before cooking.

10. Dry Clothing

Microwaving clothes is never a good idea. Rather than drying out the moisture in your clothes, microwaving it will just make the water really, really hot, and you could easily burn yourself trying to handle the item. The heat could also damage the fabric or even ignite it, so it’s just a bad idea all the way around.

Safer Alternative: If you need to quickly dry a clothing item, a hair dryer can help. Lay the clothing item out flat, and blow the hot air from the hair dryer towards it until it’s dry (or dry enough).

11. Disinfect Dry Sponges

While you can use your microwave to disinfect your kitchen sponge, the sponge MUST be wet! Microwaving a dry sponge is a quick way to start a fire, and no one wants that.

Safer Alternative: Soak your sponge before microwaving it, and check out this link for full instructions on how to safely disinfect a sponge in your microwave.

12. Cook Hot Peppers

Like the eggs I mentioned above, peppers can also explode when heated in a microwave. But hot peppers are even riskier to microwave because they contain capsaicin that can easily become airborne. Not only will you have a hot pepper microwave explosion to clean up, but it will essentially pepper spray everyone in the area too, causing painful burning in eyes and noses.

Safer Alternative: When cooking hot peppers, stick to using your stovetop, oven, or broiler, and always be careful when handling them.

13. Use Paper Bags

The main issue with paper bags is that they can’t withstand a lot of heat. They can start to smoke and may even catch fire, which is why commercial microwave popcorn bags are made with a material that absorbs microwaves and protects the paper.

Safer Alternative: You can still make your own homemade microwave popcorn—just use the glass bowl method I’ve outlined at this link.

14. Use Dishes With Hidden Metal

You already know not to put metal in your microwave, but some plates and containers may contain metal in less obvious ways. Metallic paint on dishes can be problematic, and some takeout containers may have metal handles or foil linings.

Safer Alternative: Again, make sure to look at each dish or container individually to check if it’s labeled as “microwave-safe.” If it isn’t clearly marked as such, transfer your food to a different dish or container before microwaving.

15. Run An Empty Microwave

While it’s not likely that anyone would run an empty microwave on purpose, it can happen accidentally. (I once thought I was turning on the timer when I was actually turning it on.) And that’s bad news, because if there’s nothing inside to absorb the microwaves, the magnetron inside the microwave will absorb them instead and could be damaged.

Safer Alternative: Simple—don’t run your microwave when it’s empty.

Have you had any unfortunate microwave mishaps?