10 Things You Should Never Put in the Microwave for Safety (2024)

The microwave is a marvel of modern technology. Food can go from ice cold to blazing hot in a matter of seconds. It cuts down on cook time, speeds up prep time, and all-around makes the home cook's job easier.

But not everything should go into a microwave. Some foods, beverages, and containers can release toxins, burn, melt, or even explode if nuked for less than a minute. Some may even turn toxic.

A few of these foods are fairly common—you may have even heated one in the microwave this morning. Just because something bad hasn't happened doesn't mean it won't, however, so protect yourself and others by keeping these foods away from the hot box.

Chili Peppers

Red hot, orange, or green peppers contain a compound called capsaicin that gives them their kick. When peppers are heated, especially the ultra-hot varieties, the capsaicin vaporizes into the microwave's enclosed air. Opening the microwave door exposes you to fumes that can irritate and burn your lungs, throat, eyes, and nose.

How to heat: Roast, sauté, or grill peppers instead of putting them in the microwave.

Hard-Boiled Eggs

You're tired of cold eggs for your mid-day snack, so you pop one into the microwave for 15 seconds. All seems well until you cut into the egg and it explodes—all over your office, your computer, and you.

Whether in the shell or peeled, eggs heated in the microwave release steam. The steam cannot escape the whites, so pressure builds. When you cut (or worse, bite) into the egg, the steam is released instantly. The resulting explosion may burn you.

How to heat: Slice an egg into fourths before you heat it in the microwave. If you have a few minutes, pop it into a cup of hot water, and let it sit for 3 to 5 minutes.

Styrofoam

Food-safe foam is a type of plastic that can release harmful chemicals into your food and into the air when heated. Foam is also not heat stable when shot through with microwaves. It might melt or warp.

How to heat: Place foods on a glass plate or container instead of cooking in the styrofoam. Cover with a paper towel and microwave as normal.

23 Cooking Uses for Your Microwave

Takeout Containers With Handles

The handled carry-out containers have metal, which could spark, causing a fire.

As a rule of thumb, double-check that any plastic container says "Microwave Safe" before you zap it. This label is regulated by the FDA and will tell you whether or not you'll risk exposure to chemicals if the container is heated.

How to heat: Empty the leftovers onto a microwave-safe container or plate. Top with a paper towel to block splatters and pops. Heat normally.

Mug of Water

It's much faster to heat water for tea in your microwave than to wait on a kettle to boil, but the time savings could cost you dearly. Water that is heated by itself in a microwave can quickly become superheated. While you might not see any bubbles, they can quickly form when you add a tea bag, spoon, or even just move the water. In rare cases, it might even explode.

How to heat: Let a kettle do the work. If you don't have a stove eye readily available, consider an electric option.

Grapes

Don't top your oatmeal with a handful of grapes and slide the whole dish in the microwave. Grapes become superheated, and the sugary pulp quickly turns into molten plasma. They could explode in the microwave, while you're stirring, or even when you take a bite, sending ultra-hot fruit flying.

How to heat: If you want to heat grapes, consider roasting them in the oven for a few minutes. They also heat quickly in a skillet on a medium-high stove eye.

Leftover Potatoes

Don't worry, you can still speed-cook your spuds in the microwave. But if you decide to reheat them later, take steps to keep them from becoming dangerous. Potatoes often house Clostridium botulinum, the botulism bacteria. When they're cooked and not immediately stored in the fridge, spores of the bacteria can multiply. Microwaving the potatoes won't kill the bacteria either, so your second-day potatoes could cause an upset stomach.

How to heat: Move cooked potatoes that won't be eaten into the fridge as quickly as possible. Don't let them sit at room temperature for hours on end. Reheat in the oven. A general note: Don't bake potatoes in an aluminum foil jacket. According to research, the tin catches moisture and accelerates spore growth in the warm, moist environment. For a crispier potato skin—and for the sake of your tummy—bake potatoes without the foil jacket.

Processed Meats

Bacon, hot dogs, lunch meat, and sausages should be cooked on the stove or in the oven, not in the microwave. Heating these processed meat products leads to the formation of cholesterol oxidation products (COPs). COPs have been linked to coronary heart disease. Research suggests this may also be linked to inflammation, plaque buildup in the arteries, and more health conditions.

How to heat: One study found that grilling also increased the amount of COPs in the meats, so baking in the oven or sautéing may be the safest options.

Tomato Sauce

Heating tomato sauces in the microwave often ends in splatters. The heat and steam produced by the sauce when warmed has a difficult time escaping through the thick sauce or around pieces of ingredients. The steam builds up until it's powerful enough to burst through—and onto the microwave walls. In some cases, the sauce can even explode when you stir it, which could lead to burns and certainly stained clothes.

How to heat: Heat any sauces in a small pan on the stove. This will allow even heating, and you can stir easily to prevent steam buildup.

Nothing

Never start an empty microwave oven. Without food or a container to absorb the microwaves, the beams are bounced back to the magnetron. This could damage the machine and may even start a fire. Double-check that you've put food in the microwave before you press start.

How to Clean a Microwave, the Easy Way

10 Things You Should Never Put in the Microwave for Safety (2024)

FAQs

What is unsafe to put in a microwave? ›

Metals including stainless steel and aluminum foil

Anything made of or containing steel, iron, copper or other hard metals should never go in your microwave. Metal surfaces reflect microwaves, which increases the heat inside the appliance and could lead to a fire.

What foods should not be microwaved? ›

10 Things You Should Never Put in the Microwave
  • Chili Peppers.
  • Hard-Boiled Eggs.
  • Styrofoam.
  • Takeout Containers.
  • Mug of Water.
  • Grapes.
  • Leftover Potatoes.
  • Processed Meats.
Jan 27, 2023

Is it safe to use stainless steel in the microwave? ›

stainless steel containers that are specifically designed for microwave use are safe, but regular stainless steel containers are not. This is because regular stainless steel containers can contain small amounts of metal impurities, which can cause arcing or sparking when exposed to microwaves.

Are paper towels microwave safe? ›

Most paper towels are safe to use in the microwave, but General Electric recommends reading their packaging before using them, to be sure yours fall into that category. Generally speaking, plain white non-recycled paper towels tend to be the safest.

What is the safest material to microwave? ›

Microwave Safe Dishes
  • Glass-ceramic ware and heatproof glass ware are safe in the microwave oven.
  • Oven cooking bags, baskets made of straw and wood (without metal), wax paper, parchment paper, and vented plastic bags are all safe to use in the microwave.

What are 5 rules for using a microwave oven? ›

Eight Safety Tips on Using a Microwave Oven
  • Never place metal items inside of the oven. ...
  • Only use suitable ceramic, plastic and glass dishes. ...
  • Don't place sealed containers in the oven. ...
  • Never activate this appliance when it's empty. ...
  • Remember to keep an eye on your microwave oven while it cooks food.
Jul 17, 2019

Is it safe to microwave potatoes? ›

You can cook potatoes in a microwave without adding any additional water. Just place them in the microwave and get going. This has a great advantage: potatoes don't turn moister than they were to start with. If anything, they'll dry out slightly.

What should you not reheat in the microwave? ›

6 Foods You Shouldn't Reheat In The Microwave
  • Reheating Eggs.
  • Reheating Pasta.
  • Reheating Casseroles.
  • Reheating Pizza.
  • Reheating Fried Food.
  • Reheating Really Old Leftovers.
Feb 3, 2023

Should you leave the microwave door open after use? ›

Should a microwave be left open after it's used to air out? It is not necessary. Leaving the door open is dangerous, you could accidentally snap the door off of it or you can leave the little light burning all day long using up electricity. You could even burned it out.

How long can you run a microwave empty? ›

Do not operate the oven while empty. This can cause damage to the oven or create the possibility of a fire. If, by accident, the oven should run empty for a minimal amount of time (approx 5 min), no harm is done.

Can plastic bowls go in the microwave? ›

Use glass, ceramic and plastic containers and plastic wrap that are labelled as microwave safe. Always follow the instructions on the label when you use microwave-safe containers to heat food. Never heat or store food in plastic containers that were not intended for food.

Can I use a glass bowl in the microwave? ›

Yes, you can microwave most glass items as long as they are labeled “microwave safe”. Kitchen wares, such as glass items, that have the “microwave safe” label are made of materials that are safe to be used in the microwave.

Can I put an aluminum coffee cup in the microwave? ›

This is because aluminum reflects microwaves and can cause sparking or fire, potentially damaging your microwave and even causing harm to you or others nearby. It is best to use microwave-safe materials like glass, ceramics, and plastics labeled "microwave-safe".

What is not suitable for microwave cooking? ›

Metal will spark in a microwave oven and may even cause a fire or explosion. This includes any metal utensils, dishes with metal detailing, or anything else containing metal. If you have children in the house, it's important that they are aware of the dangers too.

Why can't you put eggs in the microwave? ›

Microwave Wisdom: Why Not to Microwave Eggs in Shells

Never microwave eggs in shells. If you cook an egg in shell in the microwave, it's likely to explode. Microwaves heat so quickly that steam builds up faster than an egg can 'exhale' it through its pores and the steam bursts through the shell.

How do I know if my microwave is unsafe? ›

6 Signs It's Time to Replace Your Microwave
  1. Smoke, sparks, and burning smells.
  2. Food isn't cooking properly.
  3. It makes horrible sounds as it cooks.
  4. The door doesn't seal properly.
  5. The keypad doesn't function.
  6. It's over 10 years old.
May 1, 2019

Are there hazardous materials in a microwave oven? ›

There are several materials commonly used in microwave engineering that are deemed hazardous to your health. Generally, compounds containing beryllium are hazardous to the respiratory tract. Gallium arsenide is also considered dangerous if ingested.

Top Articles
Latest Posts
Article information

Author: Laurine Ryan

Last Updated:

Views: 5797

Rating: 4.7 / 5 (77 voted)

Reviews: 92% of readers found this page helpful

Author information

Name: Laurine Ryan

Birthday: 1994-12-23

Address: Suite 751 871 Lissette Throughway, West Kittie, NH 41603

Phone: +2366831109631

Job: Sales Producer

Hobby: Creative writing, Motor sports, Do it yourself, Skateboarding, Coffee roasting, Calligraphy, Stand-up comedy

Introduction: My name is Laurine Ryan, I am a adorable, fair, graceful, spotless, gorgeous, homely, cooperative person who loves writing and wants to share my knowledge and understanding with you.