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Can Microwave Ovens Explode?

Can Microwave Ovens Explode?

Most households now have microwave ovens. Even bachelor pads and dorm rooms rarely lack this useful cooking and meal warming gadget. Despite their popularity, they are still dangerous, and a lot can go wrong if misused.

To answer your question, yes. Microwaves can explode. Faulty wiring or placing inappropriate items in the microwave can lead to fires, smoke, and even an explosion.

How Does a Microwave Work?

Before talking about what could cause an explosion sound in a microwave, we first have to understand how the unit works. Here is a shallow snapshot.

  • Microwaves use microwave radiation for cooking or heating food by exciting atoms in whatever goes into them
  • A magnetron in the unit generates electromagnetic waves in the microwave frequency once a current flows through it
  • The waves make molecules in whatever is in the microwave cavity to vibrate quickly hence causing heat

Since microwaves can be potentially hazardous, the rest of the microwave box focuses on shielding the outside against these waves. That is why the door must be closed firmly and all microwave oven panels intact before you turn the unit on.

What Would Cause a Microwave to Explode

Microwaves don’t just explode. You shouldn’t be worried about explosions if you use a microwave safely. Some of the things that make a microwave dangerous and increase the chances of an explosion include:

Using the Microwave to Cook Certain Foods

While a microwave can cook and warm a wide array of foods, some can result in messy, scary, but mostly harmless explosions.

Check this too: How to Get Rid of Cockroaches in a Microwave


Eggs are the most notorious. Cooking an egg with an intact shell creates minimal space for the innards to heat up. 

As the egg gets hotter, moisture inside turns to steam, creating a pressure buildup. Eventually, the pressure will be more than the shell can contain, leading to a messy explosion.

Hot Pepper

Pepper contains capsaicin that is volatile. Enough pepper in the microwave could turn into an explosive combo if you keep the unit running for long enough to heat up the capsaicin to combustion temperatures.


Grapes explode because their shape (especially when cut in half) can concentrate microwave energy between pieces. This could turn air and other molecules into a plasma that will in turn arch, catch fire, or explode.

While the above are the most common exploding foods, you can still get subtle explosions when warming different types of food. For instance, liver and other seared or fried meats can cause minor or significant pops.

This happens as the juicy inside warms up and releases steam while the crunchy outer layer remains rigid to the expansion. Subtle pops and violent bangs will happen as steam breaks through this skin. 

In this case, they will be intermittently accompanied by reassuring sizzling sounds. Luckily, they only start when the food is warm enough to eat.

Placing Metalic Objects in the Microwave Oven

It is common knowledge that metal objects should never go into the microwave. This applies to everything from aluminum foil to cutlery and metal utensils.

While some experiments suggest that you can get away with forgetting some metal in your microwave, there is the possibility that it will lead to arcs and explosions if the metal is placed right.

Any sharp edges or points on metallic objects will leak electrons that interact with air, causing sparks and arcs. If these sparks interact with something flammable in the microwave at that time, a fire or an explosion could start.

Don’t listen to experiments with metal objects in the microwave that lead to no sparks. They were lucky the metallic objects didn’t have sharp tips to encourage the arcing. You might not be as fortunate.

A Faulty or Failing Microwave

The last cause of an explosion in your microwave is faults or substandard parts. 

Substandard  Parts and Workmanship

To start off, ensure that you stick to known brands with safety certification.

Unregulated microwave brands might not be up to specifications. They might be using the wrong gauge wire or inferior capacitors and magnetrons.

Eventually, these components will either fail gracefully or go out with a loud pop, some smoke, and even a fire.

Faulty or Damaged Wiring

Sometimes, a well-built microwave could explode due to faulty or damaged wiring and components. As the unit ages, parts like capacitors and the magnetron take more strain. 

An electric surge could finally overload them, making them explode. Alternatively, frayed wiring or weak connections could wiggle loose, leading to explosive short circuits or just sparks that could catch nearby parts on fire.

Can a Microwave Explode With Nothing In It?

In most cases, microwaves will explode due to what you put in them. It is very rare for them to explode without anything in them.

First of all, very few people turn on a microwave with nothing in them. With no power flowing, there is no chance of the microwave exploding.

If you are in the habit of turning on your microwave with nothing in it ( you should stop, you’re wasting power), it will be ruined and possibly explode.

All those microwaves have to go somewhere. If there is nothing to absorb them, they will all bounce around and absorb the microwave leading to a fire and even an explosion.

What Happens If You Leave a Microwave Oven On for Too Long

Most microwave ovens can keep running for an extended time without getting damaged. The only problem could be your food will either:

  • Get too hot for your liking
  • Dry up and lose moisture
  • Develop hot spots and uncooked sections if you don’t stir them often

If you must leave the microwave oven on for long, consider the following tips to keep things in check:

  • Ensure that the food is evenly spread out on a platter for even heating
  • Stop the microwave now and then to ensure a homogeneous cooking
  • Lower the power level on the microwave for extended cooking

Using a microwave on high power for an extended period could overheat main working components. While this should not be a problem if your microwave oven is well aerated, you might have to consider it still when using it on high power for extended hours.

What Can Damage a Microwave

Microwaves are sturdy and hard to damage if you use them responsibly. You will ruin your microwave if you:

Plug it into the Wrong Power Supply

Ensure your microwave is wired for your local mains power supply. While the US uses 120V, some other parts of the world use 240V mains power.

Plugging a 120V microwave into a 240V power supply will cause severe damage. A fuse could blow or an explosion, and some smoke will occur, ruining your microwave oven.

Run it for Extended Time When Empty

Running any electronic for extended periods is never good. Microwaves are also susceptible to this problem, especially if you run it for long without anything in it. This will put immense strain on electronics and the magnetron.

Place it In an Enclosed Space.

Microwave ovens need to breathe. Leaving space around and behind the oven gives sufficient airflow to dissipate any moisture or heat generated during operation.

The correct dimensions will vary depending on the manufacturer. Confirm with your specific model. When not sure, go with 5 inches all around the oven.

Placing the Wrong Things in the Oven

The last and perhaps most common reason your microwave could be failing is chucking the wrong things into it. This will either cause fires or strain the unit’s electronics damaging the unit. Some of the things that shouldn/t go into a microwave oven include:

  • Aluminum foil
  • Plastic bags and plastic containers
  • Paper bags
  • Travel mugs
  • Hard-boiled eggs
  • Grapes
  • Hot peppers
  • Lidless containers
  • Airtight containers with food in them
  • Chinese takeout boxes
  • Metallic objects like spoons, forks, and metal plates
  • Running it for extended periods (over 20 mins) without pauses at full power

Bottom Line

You should never be worried about your microwave exploding if you place the right food in it and only run it for as long as necessary. This, coupled with keeping it at an aerated place and ensuring it is clean, will give you reliable service for years on end.