Can You Microwave Cardboard? Yes in Most Instances BUT…

Published Categorized as Journal

“Can you microwave cardboard containers” might seem like a silly question at first. But honestly, it isn’t silly at all. Many people reheat their takeout in the box that it came in. These boxes are usually made of cardboard. But is this actually a safe practice? We’ve set out to find out. Let’s discover whether or not it is (actually) safe to put cardboard in the microwave. 

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Table of Contents

burger takeout in carboard box

Can You Put Cardboard in the Microwave?

Yes, you can put cardboard in the microwave – in most instances.

However, there are times when you absolutely should not be doing this. 

Can Cardboard Go in the Microwave?

Whether or not you can put cardboard in the microwave will be dependent upon a few things. Of these things include whether or not the container contains ink, metal, plastic, or glue of any sort. 

We know what you’re probably thinking. “I’m not checking my takeout box for all of those things before heating it. I’m hungry now!” However, the reality is that you could be putting yourself at risk by not looking over your cardboard box before placing it in the microwave. 

Microwaving Cardboard: Know the Risks

Putting cardboard in the microwave isn’t the most dangerous thing you’ll do in life, but it should still be approached with caution. 

Microwaving cartons and cardboard boxes that aren’t specifically marked as microwave-safe can be risky. Boxes that contain ink, plastic, glue, or metal (i.e., Chinese takeout boxes) are all unsafe choices for microwave use.

On the flip side, cardboard boxes that are pure cardboard or are marked as being microwave safe should be fine in the microwave. Still, there are protocols we think you should follow when doing so; but we’ll get to that later!

Avoid putting the following types of cardboard boxes in the microwave:

  • Boxes with a lot of ink and designs
  • Boxes that appear to have laminate or a clear “film” on them
  • Boxes that have a “window” of plastic on them that allows you to see inside
  • Boxes not marked as microwave-safe
  • Boxes with metal handles, fasteners, or fixtures
  • Boxes containing glue on the hinges or elsewhere
  • Boxes containing plastic

Another thing to remember is that it is almost impossible to know what materials are lurking in your cardboard box other than cardboard. Sure, some cardboard boxes are made of pure cellulose but not all boxes are this way.

Therefore, it is important to not microwave any containers that aren’t labeled as being microwave-safe. These boxes may contain materials that you are unaware of and may ignite when microwaved for too long. 

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How Long Can You Put Cardboard in the Microwave?

Cardboard should be placed in the microwave no longer than a few minutes. Even then, you should keep a close watch on your cardboard to ensure that everything is okay.

We don’t recommend putting your food in a cardboard box on high for 5 minutes and leaving the room. 

Use the lowest power settings when you can, and always supervise the heating of your food. Do not heat food for longer than 3 minutes when using cardboard in the microwave.

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Will Cardboard Explode in the Microwave?

It is possible for cardboard to explode in the microwave. Like paper towels and other paper items, there is always a risk of combustion when you put paper inside a microwave.

Some of the main factors that seem to determine whether or not paper will spark a flame in the microwave are time and conditions. The drier and thinner the paper is, the more likely it is to ignite. Also, the longer you heat the paper, the more likely it is to ignite. Thus, if you place thin and dry paper in a microwave for more than a few minutes, it is possible that you may soon see sparks flying!

One last concern when it comes to cardboard exploding in the microwave is whether or not oil is present. Oils in your food that leak out and onto the cardboard can increase the risk of starting a fire. Therefore, try not to microwave oily foods in cardboard whenever you can.

Can You Heat Up Food in Cardboard?

Most types of cardboard can withstand being heated in the microwave, but some fare better than others.

Check out the following scenarios to discover your best options for reheating food in cardboard. 

Can You Microwave Takeout Boxes?

You may be able to microwave certain takeout boxes, but it depends. The type of box it is matters and not all boxes are microwave-safe.

Always check for metal, glue, plastic, and ink before taking the risk. You should also look for it to say “microwave-safe” for extra security. 

Can You Microwave Cardboard Pizza Box?

So, can you microwave pizza box? You can, but don’t make it a habit.

Pizza boxes are rarely plain cardboard with no print. On top of that, pizza tends to be greasy. Both of these factors make it a not-so-great candidate for cardboard in the microwave.

A better option might be to invest in a pizza peel. This can offer up a crispy crust in the oven in only a short amount of time!

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Can You Microwave Paper Containers?

You can microwave paper containers, but the thinner they are, the quicker they may catch fire. Keep thin paper containers limited to only a minute or two in the microwave.

Thicker cardboard may be able to take a little more heat, but don’t surpass 3 minutes.

Can You Microwave Cardboard Plates?

If you’ve got cardboard plates and you are unsure if they are microwaveable, check the package.

Most cardboard plates are able to be microwaved, though we still recommend you keep an eye on them while they’re in there.

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Can You Microwave Cardboard Bowls?

Much like cardboard plates, cardboard bowls are usually microwave-safe.

To be extra certain, check the label on the package and carefully read the description before purchasing them online. 

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Can You Microwave Recycled Cardboard?

Before microwaving recycled cardboard, you should first check that it is microwave safe. Yes, we’ve said this many times now, but in this instance, it’s worth the extra attention. That’s because recycled cardboard can sometimes contain trace amounts of metal.

As most know, using metal in a microwave is a major no-no. Therefore, we advise you use caution when attempting to microwave recycled cardboard.

Can You Microwave Cardboard Cups?

Cardboard cups can usually be microwaved. Just don’t go crazy.

Sometimes these cups have a waxy interior and are inked with prints that may leach chemicals when heated. Most drinks shouldn’t require a lot of heating anyway; so keep your heating session to 2 minutes or less. 

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Can You Microwave Cardboard? Yes, in Most Cases…

In most cases, microwaving cardboard for short periods of time may be okay. Just remember never to place cardboard that contains metal, plastic, glue, or laminate in the microwave. Also, be sure to limit the amount of time you microwave oily or greasy foods. This may cause cardboard paper to ignite faster than it would in other scenarios. 

We hope this helps!

FAQs

What materials are not microwave safe?

Materials that aren’t considered microwave safe include foil, styrofoam, and anything with plastic, glue, or laminate. You’ll also want to watch for prints and designs, even on paper towels. The ink used to create this design can leech into food and make you sick. 

What happens if you eat off of microwaved cardboard?

We recommend eating off of a plate rather than cardboard. Cardboard heated in the microwave may contain chemicals and fumes that can end up in the food you eat. Moreover, the box often gets soggy after heating and can cause bits of cardboard to end up in your meal. Gross!

Is cardboard toxic?

Certain types of cardboard, such as recycled cardboard, may be toxic. This is why you should be careful what type of cardboard you choose to place in the microwave.

Published
Categorized as Journal

By Anna

Hey, I’m Anna; writer, editor and amateur cook extraordinaire! Food has been my life and my passion for the most of my life – it’s crazy to think I didn’t pursue a career in cooking. I’m obsessed! However, keeping cooking as an obsessive hobby has worked for me – my passion grows as the years pass by – maybe I wouldn’t say the same if it was also my day job! I hope you find cooking inspiration, entertainment and “stop and think interesting tid-bits” throughout my writing – and I’d love to hear from you if you’ve got anything you want to share. Food feeds the soul – so get eating!

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