Your Guide to Being Microwave-Safe: Stuff NOT to Zap in Your Microwave

There are events in history that are real game-changers, like the invention of the microwave. There was life before the microwave and life after the microwave. And anyone who grew up with a microwave in the house can’t even imagine life without it. Right?

A woman looks like she is not sure what to put into the microwave.
Photo by tsarevv /

But, as convenient as a microwave is, that doesn’t mean you should put every darn thing you want to make hotter. Some things are downright dangerous if you zap them in the microwave. Other things are simply not worth it. Here’s a list of all the things that you definitely shouldn’t heat up in the microwave.


Cooking eggs in the microwave has become popular over the years, but as convenient as it is, it’s not worth it. Why? Because the egg can explode. A microwave works by emitting radio waves directly onto the food. And when it comes to eggs, it means a large amount of steam comes out of the egg, causing the egg to explode.

Photograph of egg exploded in the microwave.
Photo by Edeli R. de Almeida /

Now, if I can just remind you that every time you eat breakfast at your favorite diner, those eggs come off a steaming frying pan. And the eggs taste good, right? Yeah, so fry up those eggs, people. It only takes a couple of minutes.

Frozen Fruit

In general, fruit in the microwave is never a good idea. And zapping frozen fruit is even worse. It may seem like a simple way to defrost fruit when you don’t want to wait around, but it can have harmful consequences.

A variety of frozen fruit next to the microwave.
Photo by Galina Bondarenko /

The microwaving process converts the fruit’s healthiest properties into carcinogens that will compromise your immune system. Next time, make a reminder to take fruit out of the freezer and let it defrost at its own pace.

Raw Rice

I’m not sure how many people try to cook raw rice in the microwave, but if you’re thinking about, you should know just how risky it is. Rice can host certain bacteria, which can lead to food poisoning.

Photograph of a women preparing rice in the microwave.
Photo by sergemi /

The conventional method of cooking rice in boiling water destroys these bacteria. Microwaving may not. This means there’s the potential to get food poisoning. Bottom line: rice is meant to be boiled.


Heating up water in a microwave doesn’t make much sense if you ask me. Yet people still do it. Why not just the equally time-efficient kettle? Or even in a pot on the stove does the job quickly.

Inside view of a glass of water in the microwave.
Photo by Marian Weyo /

Aside from that, microwaving water can be dangerous as it can heat the water beyond its boiling point. So, when you take it out of the microwave and add something to it, it can burst and burn you.

Fine China

That pretty little china milk jug that Grandma gave you? Don’t put it in the microwave when warming milk for your guests’ coffee. Most china contain a type of metal component to give an aesthetic effect.

Photograph of a cheeseburger on a plate with designs made of metal components.
Photo by D. Pimborough /

And if no one ever told you – metal should never go in the microwave. Metal parts can be damaged when zapped. More importantly, the sparks caused by the microwave can cause a fire.

Here’s a general rule of thumb: if the object was made before microwaves, it should stay out of microwaves.


You should know that microwaving bread to either defrost or warm up is actually safe. But safety isn’t the only reason not to zap things in the microwave oven. Ever considered the factor of texture and flavor?

Photograph of sandwiches in the microwave.
Photo by NatalyaBond /

The process can remove all the texture and flavor from the bread, leaving it soggy and tasteless. Yuck. Put the bread in the oven or toaster. It’s worth the wait.


Cooking chicken in the microwave might sound really convenient and really efficient. But it’s really not a good idea. The problem with chicken in the zapper is that it doesn’t cook evenly.

Photograph of a raw chicken inside of a microwave.
Photo by NatalyaBond /

So, you can find yourself with chicken that looks well cooked on the outside but is raw on the inside. And anyone who had salmonella poisoning will urge you to avoid any unnecessary risks of eating uncooked chicken.

Red Pasta Sauce

The kind of tomato sauce we use for pasta is very thick, a consistency that makes it less ideal for microwaving. It’s because the radio waves have a difficult time making the sauce’s particles move in order to warm them up.

Meat in a red pasta sauce exploded in the microwave.
Photo by anderm /

So all you get from warming pasta sauce in the microwave is the popping sound of it splattering all over the walls (and the roof), leaving you with a frustrating clean-up job.

Leftover Mushrooms

If not mushrooms aren’t stored properly, they can make you very sick if you reheat them in the microwave. Mushrooms are a breeding ground for microorganisms, and when reheated, it can lead to food poisoning.

A container with cooked mushrooms and potatoes being placed in the microwave.
Photo by Africa Studio /

The best method is to refrigerate mushrooms after they’ve been cooked and also cooled down. That way, you can make sure that they won’t make you sick when you heat them up again.

Breast Milk

This one is for all the exhausted moms out there with small babies, trying to juggle the responsibilities of motherhood while also running a home and having a career. Pumping breast milk and freezing it is a popular method.

Photograph of a baby bottle being placed into the microwave.
Photo by Aleksandr Mokhnachev /

But don’t ever warm the breast milk in the microwave! The microwave doesn’t heat the milk evenly, leaving “hot pockets” of milk that can burn the baby’s mouth.

Cooking Oils

Cooking oils, like sunflower oil and olive oil, should never be put in the microwave. These oils won’t warm up properly because they’re made up of fats (not liquids).

Photograph of a woman placing a cup of oil into the microwave.
Source: Pinterest

Exposing them to the microwave’s radio waves won’t have any effect on them at all. If you need hot oil for a meal you’re making, it’s quicker and more efficient to warm it up on the stove.


Styrofoam is designed for single-use (unfortunately), and it also contains plastics. That’s why microwaving it will change its shape and constitution, releasing harmful chemicals that are in contact with the food in the Styrofoam container.

Person holding two Styrofoam take out containers. / A woman warming something up in the microwave.

When you eat the food after, those chemicals will get into your system and make you sick. Remember folks, just because you can’t see them doesn’t mean they’re not there.

French Fries

This is similar to the advising against putting bread in the microwave. When French fries are reheated in the microwave, they lose all their texture, going from crispy to soggy. Not to mention flavorless.

A person putting french fries and fried chicken in the microwave.
Photo by Andrey_Popov /

It doesn’t mean that they can’t be microwaved. Fries won’t create any damage to your microwave or your digestive system, but most people would agree they’re best served freshly cooked.

Processed Meat

Microwaving processed meats, i.e. hot dogs and sausages, is not the best method for health reasons. Processed meats are full of preservatives, and when these preservatives are exposed to the radio waves from the microwave, they stimulate cholesterol oxidation.

A heap of chicken sausages in the microwave.
Photo by Various-Everythings /

Cholesterol oxidation can cause heart disease. In general, processed meat isn’t healthy, and microwaving it only increases the danger. So it’s best to stay away.

Sharp Objects

Even if a sharp object isn’t made of metal, it should not be put into the microwave. Something as harmless as a toothpick can be a potential hazard in a microwave oven.

A cup of toothpicks on a wooden table. / A woman closing the microwave door.
Photo by NUM LPPHOTO, / Andrey_Popov,

Sharp objects can cause sparks to fly in a microwave oven. And sparks mean fire. Oh, and those twist-ties you love to use to close up bags of food? Those have metal in them. So watch out.

Uncovered Containers of Sauce

If you want to microwave sauce before serving a meal, make sure the lid of your container is sealed well. Open sauce containers can explode in the microwave oven.

Photograph of an uncovered jar of food which has exploded in the microwave.
Photo by Linda Bestwick /

This will leave you with a huge mess to clean up. And cleaning a mess after using a microwave defeats the purpose of using the microwave in the first place – efficiency!

Hot Peppers

Hot peppers contain capsaicin, the ingredient that gives the peppers their spicy flavor. And while it’s useful for treating a variety of ailments, it’s not a good idea to put them in the zapper.

Photograph of peppers sitting on a plate in the microwave.
Photo by Claudio Divizia /

When capsaicin is microwaved, a vapor is emitted that will leave your eyes, nose, and mouth stinging for a long time. Peppers can also explode in the microwave, leaving yet another mess to deal with.

Old Vintage Mugs

Many of the mugs made before or during the 1960s should never be put in the microwave oven. Many of them were included in the process of being glazed with a substance that gives off radiation when in contact with the radio waves emitted by a microwave.

Photograph of a mug sitting in the microwave.
Photo by Monkey Business Images /

Older mugs can also hold metal or lead, which can cause a fire in your microwave oven. By all means, use these cool-looking mugs for coffee or as decoration. Just don’t zap them up.

Disposable Plastics

One-time-use plastics like yogurt containers and butter tubs that aren’t made to be reused should not reheated in a microwave either. They were never treated with the same processes as reusable plastics.

Photograph of a one-time-use plastic container being used to heat up food in the microwave.
Photo by /

They can release harmful chemicals when exposed to heat. If you want to microwave something that was stored in one of these plastic containers, first transfer it to a microwave-friendly container.

Travel Mugs

Don’t put your travel mug in the microwave oven. They’re usually made from stainless steel, and stainless steel will repel the radio waves that the microwave oven emits.

Silver travel mug for a hot drink. / A person using the microwave.
Photo by S_Photo, / Kostenko Maxim,

When that happens, the liquid inside your travel mug won’t warm up. The radio waves just bounce around the microwave and can cause damage to your microwave.

Plastic Wrap

Go ahead and use plastic wrap to cover containers of food if you don’t have a lid. But please remember to get rid of the plastic before putting the container in the microwave.

Some delicious looking food on a plate wrapped in plastic wrap.
Photo by jreika /

Since it’s plastic, the cling film can release harmful chemicals like benzene, toluene, and xylene in the microwaving process. When these come in contact with your food or are breathed in, it’s bad news.


Like I mentioned earlier, fruit in the microwave isn’t a good idea. If you’re looking to make stewed fruit, it’s best to keep it conventional. Grapes, in particular, are prone to exploding in the microwave.

A cup of frozen grapes next to the microwave.
Photo by Galina Bondarenko /

Grapes, along with their dehydrated cousins (raisins), release plasma when microwaved. It causes them to emit smoke, and this can break your microwave at worst. At best? They’ll leave you with a sticky mess.

Aluminum Foil

Whether this may seem obvious by this point, it’s still my duty when making a list like this to include aluminum foil as a non-microwavable item. Like any metal, aluminum foil doesn’t go in the microwave oven.

A large aluminum tin with a turkey inside of the microwave.
Photo by Chad Hutchinson /

It reflects the heat, causing sparks to fly. You’re either going to need to run for the fire extinguisher or replace your microwave.

But if you’re looking for things that you CAN do with aluminum foil, check out these hacks

Leafy Greens

It might seem logical to microwave your kale or other leafy greens, but they can create sparks when microwaved. And as we’ve learned, sparks can lead to flames, and flames can lead to a disaster.

A woman placing a pizza with leafy greens on it in the microwave.
Photo by sergemi /

Leafy greens should be prepared in the oven or on the stove, which also results in much better flavor than those that are microwaved. Microwaving them just leave you with limp and tasteless greens. The best method? A steamer.

Chinese Food Containers

What’s better than Chinese takeout? Having leftovers for lunch the next day. Am I right? Well, as easy as it is to place the whole thing in your microwave, think again.

Chinese food take out in the white square container
Photo by Joshua Resnick,

Chinese takeout containers typically have little metal handles on them. They might be small and unnoticeable to most people, but the presence of metal in a microwave oven is a big no-no. Transfer the yummy leftovers to a safe dish first.

Paper Bags

If you want to heat something (whatever that thing may be) that’s inside a paper bag, remove the item from the bag first and then put it in the microwave.

Burnt paper bag with melted and burnt popcorn after a paper bag exploded in the microwave.
Photo by DeymosHR /

The radio waves can cause the paper to catch on fire, which can cause your microwave to catch on fire and be destroyed. Do you really want to deal with a fire right now?

Kitchen Sponges

Believe it or not, a lot of people (maybe even you!) use the microwave to clean kitchen sponges, thinking that the high temperature will kill all the bacteria and microorganisms. This is just not true.

Photograph of a pink sponge sitting in the microwave.
Source: Pinterest

Some bacteria are left behind and just go on to grow more in the sponge. With time, the bacteria can even become more resistant to the heat in the microwave. Use anti-bacterial cleaner or bleach to keep your sponges clean. Or, you know, buy a new one.


You might be wondering why anyone would want to microwave yogurt in the first place. I’m still trying to figure it out. Who knows – maybe for a picky kid who only eats yogurt when it’s warm?

Photograph of a bowl of yogurt next to the microwave.

Anyway, it’s better to soak the yogurt container in hot water for a few minutes. Putting it in the microwave will only kill all the useful bacteria that comes in yogurt. Zapping it will also cause the yogurt to curdle. Yuck.

Biscuits and Cookies

After only 10 or so seconds in the microwave, most of the moisture leaves the cookies, turning them into a hard, chewy challenge. It’s due to the gluten, starch, and sugar reacting when heated and then cooled.

Cookie bars being placed into the microwave to cook.
Photo by Ahanov Michael /

It’s actually the cooling process that makes the cookies hard. If you take cookies out of the freezer, let them sit out and thaw on their own. No need for a microwave in this case.

Raw Peanuts

Raw peanuts can be roasted in a microwave, but only after you remove the shells first. If you’re looking for a way to do it, try this:

A woman removing the shells from peanuts.
Photo by Horth Rasur /

Put the shelled peanuts in a glass container and add small slivers of butter. Place them in the microwave for about 2 minutes and then stir. Microwave for 2 more minutes and stir again. After about 10 minutes, they should be roasted.


Cooking your hummus in the microwave might be faster using other methods, but it isn’t always the best way. According to a study done at Virginia State University, microwaved hummus doe indeed hold more nutrients, but it also makes it lose its protein content.

Home made Hummus with olive oil and pita chips.
Photo by Brent Hofacker,

Their research showed that soaked hummus prepared in the microwave held 21.8 grams out of the 100 grams of protein it originally had.


Bananas in the microwave are capable of catching fire and creating light explosions. Someone posted on a question-and-answer forum asking for an explanation as to why this happened to him in his kitchen.

Photograph of bananas sitting in the microwave.
Photo by The Picky Fork /

The answer he got was that store-bought fruit usually has a waxy covering that might have encouraged the threads on the edge of the banana to light up. Bananas are also slightly radioactive.


If you like corn when it’s soft and juicy, cooking it in the microwave isn’t the way to go. Corn that’s been cooked in the microwave tastes dry when compared to corn was boiled on the stove.

A person carryng corn to the microwave.
Photo by HelloRF Zcool /

Some people argue that you could boil your corn in the microwave, but doing so will come at a cost. When boiling your corn in the microwave, radio waves are created that heat your water by making it vibrate. This vibration causes the water to spill inside the oven.


The microwave isn’t a good choice when it comes to softening butter because it’s likely that it will get unevenly heated. When your microwave is producing heat, some spots get a higher concentration of it than others.

A woman placing butter into the microwave to heat it up.
Photo by PixieMe /

This could make your butter hard in some places and soft in others. Sometimes your butter may even melt in certain areas because of this, and if your microwave oven doesn’t have a turntable, your butter will be at greater risk.


When cheese is melted in the microwave, it can get rubbery, which doesn’t make it look or taste delicious. Scientists say that time and heat plays an important role in how cheese melts in the microwave, but they also acknowledge that melting it in the best way possible still doesn’t make this method foolproof.

Process of taking a plate with pasta and cheese out of the microwave.
Photo by Africa Studio /

That’s because the hot air from a regular oven is non-existent in the microwave. That hot air is what creates that “crust” on your cheese that prevents moisture from getting on its surface, thus saving it from getting rubbery.


You’ll find a lot of microwaved onion recipes online these days, but does preparing onions using this method mean they turn out good? It’s not the best method.

A bowl of vegetables being placed in the microwave.
Photo by Africa Studio /

If you put onions in the microwave and they turn out soft and flavorless, don’t be surprised. And if you put them in there for longer in the microwave, they still won’t get crispy; they just dry up and become a fire hazard.


Don’t have a clothes dryer at home? Well, don’t think that your microwave is a substitute. You might be tempted to pop your socks into the microwave on a cold morning, but don’t actually do it.

A cup of frozen fruit next to the microwave.
Photo by Galina Bondarenko /

Your clothes don’t contain any moisture, so the microwave has nothing to pull energy from. Socks are too dry for the microwave, which means they can cause a fire to break out.

Herb Drying

If you think your microwave is going to help dry out the herbs you’ve been growing in your garden so you can package and use them, you can think again. Herbs don’t hold a lot of liquids.

Assorted fresh herbs in a garden. / Photograph of someone placing a bowl into the microwave.
Photo by stockcreations, / Nitikorn Poonsiri,

Once the liquid content is gone, you’re just creating a fire hazard. Stick to the conventional methods for drying herbs if you want all your hard work in the garden to pay off!

Potato Leftovers

Potatoes may seem harmless, but after they have been cooked and cooled, the process of reheating them can have important consequences. When you cook potatoes, let any leftovers cool down completely and then refrigerate them.

A woman putting a container with fried potatoes, chicken meat and sausages into the microwave.
Photo by Africa Studio /

When leftover potatoes are taken from the fridge and then microwaved, they can trigger botulism, a serious disease. Left untreated, botulism can be potentially fatal.