Can you microwave aluminum trays? (Is it Safe)

If you have been using the microwave to heat your food for a while now, I know this question must’ve come up in your mind whether it was possible to microwave food in an aluminum tray. 

From days of yore, we’ve heard that using metals (be it containers, or the decorative gold and metallic rims on dinnerware) inside a microwave will create sparks and you could end up damaging your device. So why put your microwave at risk just to test out a “theory”?

Well, lucky for you I went ahead and researched this topic to put this myth to the test. Did I bust this myth or is it plausible and sparks did fly? Read on ahead to find out….

Can you microwave aluminum trays?

Yes, aluminum trays that contain frozen or ready-to-eat meals can be used safely to heat food in a microwave.

Is it safe to microwave aluminum trays?

Yes, microwaving aluminum trays (not foil) is safe.

The Fraunhofer Institute in Germany has put the safety of this theory to the test. After conducting a series of experiments, they concluded that no damage to the microwave ovens occurred when the aluminum trays were microwaved, even at the highest power.Even the USDA has further verified this by stating “It can safe to use aluminum foil in small amounts in the microwave”

So rest assured that you can easily microwave your takeout meals or defrost frozen foods in aluminum trays.

Safety guidelines for microwaving aluminum trays:

While it has been determined that aluminum trays are safe to use in a microwave, make sure you follow these safety tips to keep your microwave in perfect running order.

  • Avoid using foil or foil-lined lids to cover the aluminum trays while microwaving. Because the food will not be heated properly if it’s is completely encased in aluminum (aluminum will reflect the microwave rays)
  • Only use aluminum trays with shallow edges, no deeper than 3 inches for microwaving food. Containers with higher walls will not allow the microwave rays to penetrate and heat the food.
  • Make sure your aluminum container doesn’t touch the sides of the microwave. Metal touching metal can potentially create a spark.
  • Do not use bent or crumpled foil trays for the same reason as above.
  • Do not stack multiple containers on top of one another inside the microwave.
  • Never microwave an empty aluminum tray, always keep some food inside. This is because, without the food to absorb the microwave rays, they will be bouncing back to the oven walls and possibly end up damaging your oven.

How to heat food in aluminum trays in the microwave?

Aluminum containers are pretty convenient to use in the microwave because they can be placed as is in the microwave without the need of transferring food to any other microwave-safe dish first.

Heating the food in them is pretty straightforward too. Double win!! Here are some guidelines to keep in mind when you heat your food with aluminum containers:

  1. Remove the lid or any covering such as plastic wrap or cardboard before placing the tray in the microwave.
  2. Cardboard is more prone to catching fire so be mindful of it.
  3. Fully spread the food to cover the bottom of your aluminum tray, so that not only does the food heat evenly there is no portion of the aluminum exposed directly to the microwave rays, which will result in the rays bouncing around and not heating the food properly.
  4. Always make sure you place the tray in the middle of the oven. The size of your aluminum tray should be the appropriate size for the microwave. If it’s touching the walls of the microwave, then it may create sparks.
  5. Always keep one tray in the microwave to heat at a time. Keeping more than one tray together may mean that the trays are touching one another and could create sparks inside the microwave.

Can I use aluminum foil-wrapped food in the microwave?

This is an oxymoron of sorts. You can use a microwave to heat food on aluminum trays but not aluminum foil-wrapped food.

What’s the difference you ask? Both are made from the same material after all. While yes, they are, turns out that it’s the thickness of the aluminum plays an important part in deciding whether it can be placed in the microwave or not.

When you place a heavy or thick metal container, like an aluminum tray, with food inside the microwave it will act as a mirror and start reflecting the microwave rays (This is the reason why it is advised to leave the food in aluminum trays uncovered while microwaving, so that the bouncing rays can enter and heat the food from the top since the walls of the tray will be reflecting those said rays)

But when you wrap food in an aluminum foil (note the thickness of foil vs. trays) you will inadvertently be crumpling up the foil from most places. Two things happen here:

  1. The thin foil will heat up more quickly than a tray
  2. The crumpled edges will cause the electric currents to flow very quickly through the foil and create sparks. If you have any wax paper along with it in the microwave, you are saying hello to a potential fire hazard as well.

So for safety’s sake, just stick with keeping ONLY aluminum trays inside the microwave.

Will microwaving food in Aluminum containers create any health issues?

Let me present you with all the facts and then you can decide for yourself. In my opinion, I would call this statement partly false.

Aluminum exposure in healthy adults:

If you are a healthy adult with no underlying health issues, then aluminum in your food or drink shouldn’t be a matter of concern. 

Our bodies may be exposed to some aluminum if acidic food is cooked in aluminum cookware or it can come from exposure to other sources like water, food preservatives, etc. as well.)

In reality, however, our bodies absorb only 1% of our total exposure to aluminum. This number may vary depending on the lifestyle and dietary modifications. But our kidneys are responsible for clearing out around 95% of whatever aluminum intake we might have. Healthy kidneys = healthy detoxed body.

Even the FDA considers aluminum safe enough to be used for food preparation ingredients and medicines.

Aluminum overdose in adults with impaired kidney function:

The reports that mention neural disorders like Alzheimer’s linked to aluminum were carried out on elderly people with impaired kidney function. Since they were not able to flush out whatever aluminum they were being exposed to it created multiple (not just neural) health issues for them.

Other cases of aluminum causing health problems occurred in people with long exposure to aluminum, way beyond what a normal person may be exposed to, such as people working in aluminum manufacturing plants and mines or soldiers with pieces of aluminum shrapnel embedded in their bodies.

Why are aluminum trays best for heating food?

In this fast-paced life that we are living in, washing dozens of pots and pans after preparing a meal can seem like a heavy task (not forgetting the dishes after, the bigger your family, the more the dishes. Yikes!) 

Not only is using pre-cooked/frozen meals convenient for when you have little time but so much to do, but using the aluminum trays that they come in to serve it as well can improve its presentation. 

If that is not enough reason for you to choose aluminum trays as a microwave-safe container, then let me give you some more reasons why choosing them seems like a good idea.

  • Safety – unlike plastic or styrofoam which can melt and mix in with your food, aluminum won’t betray you.
  • Convenience – No more cleanup after dinner. You could simply toss out the container for recycling or wash and reuse it at home again.
  • Multipurpose cooking – Aluminum trays are safe to be used in both conventional ovens and microwaves alike.
  • Durability – these containers can be reused again and again and what’s more, unlike paper containers won’t burn or melt like plastic when exposed to heat.

Conclusion

Aluminum trays are a safe option to be used as a microwave-safe container for your food. But keep in mind that while these trays can be safely used aluminum foils cannot. So don’t attempt to use that in the microwave and you are good to go.