Last Updated: February 13, 2021

Can You Microwave Aluminum Foil

Can You Microwave Aluminum Foil

Most of us have been told time and time again how microwaving aluminum foil is a big no. It has so many health hazards and can be very dangerous. But what if I told you that it is possible to microwave aluminum foil? Can you microwave aluminum foil? Should you? 

Let’s answer these questions one at a time.

Can You Microwave Aluminum Foil?

Yes! Most people are unaware of the fact that you can, in fact, microwave aluminum foil. According to the USDA Food Safety website, you can successfully microwave your aluminum foil under certain circumstances. 

But, hear me out, the reason people strongly advise against this is that it can turn very dangerous very fast, and you don’t want to take that kind of risk. 

How Does Microwave Cooking Work?

To know why microwaving aluminum foil- or any metal for that matter- could be dangerous, we need to first have a look at how the microwave operates while cooking food.

Microwave ovens make use of radio waves that have a frequency of about 2.5 gigahertz. These radio waves are then absorbed by sugars, waters, fats, and oils. Basically the food items. These waves, when absorbed, get converted into heat. However, these waves do not have any effect on the glass/ceramic/plastic containers that we use inside the microwaves. Therefore, microwaves will only ever heat your food without raising the temperature of the containers.

Furthermore, the walls of your microwave oven are made up of metal. So what they do is play the role of a mirror and reflect the microwaves (radio waves) around. This is the reason your food can be heated so quickly in a microwave.

Also important to note is how metals reflect the radio waves instead of absorbing or being unaffected by them.

What Happens If You Microwave Aluminum Foil?

Now that you know how a microwave works, it should be easier to understand this part. Metal, when placed inside a microwave, deflects the electromagnetic waves emitted by the device. Since the walls of the microwave are already reflecting these waves, your food never really heats up at all.

The radio waves keep bouncing back and forth between the foil and the walls of your oven. This could potentially damage your device.

Can You Microwave Aluminum Foil: Is It Safe?

Can you microwave aluminum foil? Yes. Is it safe? Not really, no.

The problem with most microwaves is that each unit differs from the next. Depending on factors like wattage, brand, how old they are, and their capacity, each microwave will react differently to things.

If you microwave aluminum foil, it will either emit sparks and catch fire, or do nothing at all. The higher the wattage of your microwave oven, the more likely your foil is to catch fire.

Any sane person would ask to just eliminate the risk at this point. But the USDA Food Safety unit also notes down certain conditions under which it might be safe to microwave aluminum foil. 

While it might still be risky, you could glance over them once.

Rules for safe use of Aluminium Foil:

  • Use smooth foil only. Any wrinkles in your foil can cause sparks.
  • Only cover 1/4th of the food with foil.
  • When shaping the foil, make sure no rough or pointy edges stick out.
  • Maintain a distance of at least one inch between the foil and the oven walls.
  • Microwave ovens with metal shelves or metal turntables will never work well with aluminum foil. Don’t try it.
  • If you see any sparks at all, switch off the microwave and remove the food immediately.

Why You Shouldn’t Microwave Aluminum Foil

Now that we’ve talked about the whats and ifs of microwaving aluminum foil, I have one last piece of friendly advice for you.  

DO NOT microwave aluminum foil. I know that some people don’t mind it and that some people do use a lot of metal equipment in their microwaves. Some even believe that learning to microwave metal the right way eliminates all risks of causing a fire. But that’s not true!

Although it would be fun to be able to microwave food however you liked, without having to worry about whether the container is microwave-safe, the risk is not worth the results. 

First and foremost, when you microwave metals, the electrons move around on the surface. These then cause sparks. There are hundreds of cases of microwaves catching fire, or leading to severe accidents when used wrong.

This MIT article talks in-depth about why you shouldn’t microwave metal objects! 

What Are Other Alternatives to Microwaving Aluminum Foil?

I wouldn’t blame you if you thought that the world couldn’t survive without owning a microwave. For the longest time, I thought so too! 

But here’s the good news, there are so many alternatives to microwave cooking! And especially if you’re sad that you cannot heat your favorite takeout food in the microwave because of its aluminum packaging, these are worth checking out! 

  • Ovens- If you wish to reheat your food in the aluminum packaging it came in, ovens can be a great option! Not only can you cook, bake, or grill your food, using aluminum foil in the oven aids faster and better cooking of your food!
  • Toaster Ovens- These compact ovens are smaller, more compact, and save greater energy than regular convection ovens. They cook your food a lot faster than convection ovens do, and are generally considered a greener environment choice.
  • Casseroles and dutch ovens!
  • Rice cookers- You’re wrong if you thought rice cookers are only meant for making rice. They can do so much more! They can even reheat your food, and help you with baking food!

You may also like: How to Melt Hard Candy

Why Can You Use Aluminum Foil In The Oven But Not In The Microwave?

We’ve all wondered about this at some point, haven’t we? We don’t really think twice before popping an aluminum bowl or a takeout container in the oven. But then why don’t the same rules apply to the microwave?

The major difference between a microwave and a convection oven is the way they heat food.  Most ovens use a heat-insulation technique where the food is gradually exposed to heat/ naked-heat. Microwaves, however, make use of radio waves to heat the food.

In short, ovens heat food by exposing it to heat whereas microwaves expose the food to radiation that then generates heat within the food. In the oven, therefore, there’s no risk of the electromagnetic waves reflecting on the foil, risking a fire.


Is it safe to microwave aluminum foil?

Not really. Aluminum in the microwave risks emitting sparks or causing a fire. It is better to avoid microwaving food in aluminum foil.

Is aluminum foil toxic when heated?

It is not normally toxic to heat food in aluminum foil. However, high temperatures may cause the aluminum to leech into the food. While it might still not be toxic, it is something you should be careful about.

Is it safe to reheat food in aluminum foil?

Absolutely! In fact, most recipes ask you to cover, line, or partially coat your food with aluminum foil.

Final Thoughts

I’ve said this before and I’ll say it again. Do not attempt to microwave your food in aluminum foil. It may be possible and feasible for some, but it is definitely not worth the effort nor worth the risk.

If you wish to reheat your aluminum takeout containers, opt for ovens. If your recipe calls for using aluminum foil, switch to other means of heating it. I hope this article successfully cleared any doubts you had. If you should have any further queries, feel free to drop them at the end of the blog.

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