Why Did My Microwave Catch Fire?

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Updated August 17, 2022

If you have been an avid user of the humble microwave oven, you may have experienced an issue or two, causing you to wonder why did my microwave catch on fire. Even the best microwaves, can run into major problems and catch on fire. What causes microwave fires and how can you prevent them? Keep reading to find out.


  • Microwave fires are commonly caused by overheated ingredients, so keep an eye on your food as you cook.
  • If you place metal, such as aluminum foil, or food packaging inside of the microwave cavity, it could start a fire.
  • Electrical issues can also lead to fires, including power surges and shorted-out power supply units.

What Causes Microwave Fires?

There are, unfortunately, plenty of reasons why a microwave oven can catch on fire during use or even when it is not being used. Here are a few cases in which microwave energy transforms into fire. That said, other elements you can manage include using a grill in a microwave, preventing the microwave from interfering with the WiFi, and what can happen when you put foil in the microwave.

Insider Tip

To avoid fires, be sure to always keep an eye on your microwave as it cooks. If a fire does occur, it will typically go out on its own.

Overheated Food

A primary culprit behind microwave fires is overheated food. A conventional microwave uses heated electrons and electromagnetic waves to cook food, which does not cause smoke or fire on its own. However, if an ingredient becomes overcooked, it could begin to smoke and catch fire. How to prevent this? Keep an eye on your ingredients as you use a microwave and adjust the settings accordingly. You may also want to learn how microwave sensor cooking works.

Metal and Packaging

Other big firestarters when it comes to microwave cooking are metal objects and packaging being left inside the cavity as you cook. When you read that a bowl or a plate is “microwave-safe”, that means it can rest inside the cavity without catching fire. The same cannot be said for garden variety metals, like aluminum foil, and many of the materials that go into food packaging. How to prevent this? Always double-check before putting something inside of the microwave for best microwave safety practices. The same can be said for accessories, so if you are wondering how to work a microwave with a grill, be sure it will not catch on fire.

Electrical Issues

There are a few electrical issues that can lead to microwave fires. If the power supply shorts out, for instance, it could cause a fire. The same can be said for a power surge. On rare occasions, a power surge will “trick” the microwave into turning on, causing it to run continuously until you shut it down. This, obviously, can lead to a fire. Microwaves also include a variety of electrical components, each of which can malfunction and start a small fire.


Why do veggies spark in the microwave?

Microwaves produce an electric field as they operate, which can sometimes cause veggies, such as green beans, to spark as they cook

How to use a microwave safely?

Avoid metal objects, such as aluminum foil, and objects with pointy edges, as these edges could contain hidden metal or metal trim. Yogurt cups could also be an issue.

Do paper towels catch fire in a microwave?

Paper towels are fine for use in a microwave, though the same cannot be said for minute metal flecks, pieces of metal, and a ceramic container. Make sure, though, that the paper towels are not 100 percent cotton.

STAT: Don’t use 100% cotton items in the microwave, as they can catch fire. (source)

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