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Can You Put Cardboard In The Oven?

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When ordering pizza takeout, you might have left it to sit a little too long and need to warm it up before eating. Or you may have bought a store-bought pizza and are not sure whether to remove the cardboard base or not before placing it in the oven.

Another cardboard conundrum – you have takeout that has come in a cardboard box that needs to be heated up.

So, can you put cardboard in the oven? You might be able to get away with putting cardboard in the oven at low temperatures, but it is not recommended, as cardboard is combustible and there is always a chance that it may smoke, burn, or catch fire if left in the oven at higher temperatures.

Knowing when it is or isn’t safe to put cardboard in the oven will definitely help you out in the kitchen.

We have covered all you need to know about whether or not you can use cardboard in the oven, and what alternative options there are to use instead of cardboard below. So read on, curious cooks!

Is Putting Cardboard In The Oven Safe?

Some people do place cardboard pizza boxes, cardboard pizza bases, or cardboard takeout boxes in the oven to heat up food, or keep it warm, and while this might be fine in the right conditions, it is something that is not considered particularly safe to do.

If you need to keep something warm, say a pizza in a cardboard box, you can simply pop it into the oven without turning it on.

The insulation alone will help keep your pizza warm until you need it. You can also turn it up to a low temperature, say 150°F, for a few minutes if needed.

We recommend avoiding putting cardboard in the oven at higher temperatures if you have a good alternative available.

Cardboard is a combustible material, and with the oven being a high-temperature environment, there is a good chance that the cardboard might catch on fire and burn if left in the oven for an extended period of time, which really doesn’t even have to be that long.

Those who have been successful with using cardboard in the oven would have seen the food act as a barrier between the cardboard and the heating element.

The cardboard is much more likely to catch fire if placed directly onto the element, but leaving it in the oven for a long time could result in it burning too.

So while there are some people who claim to do this often, it is not worth the risk, and you don’t want to have a smoked-out kitchen because you left cardboard in your oven a bit too long.

What Is The Ignition Point Of Cardboard?

The ignition point of cardboard is 427°F, so if it is placed in the oven and the oven reaches this temperature or higher, the cardboard will most likely catch alight.

Even before reaching this point, if the cardboard stays under 427°F, there is still a chance that the cardboard could begin to burn in the dry heat, or that it could catch alight, depending on the type of oven you have and how humid the air is.

Why You Shouldn’t Place Cardboard In The Oven

Whether you are wanting to warm up pizza, frozen meals, or Chinese takeout from the night before, there are a few reasons you might consider placing cardboard in the oven.

To explain why this may be a bad idea, here are the reasons why you shouldn’t place cardboard in the oven!

1. Fire Hazard

One of the most obvious reasons why you should not place cardboard in the oven is that the cardboard might catch on fire, and this will not only ruin the food it is holding, but it could pose a huge fire risk in your home as well.

Cardboard can ignite at 427°F, and there are a few foods that need to be cooked just under this temperature. The risk of the cardboard bursting into flame is just too high, and it really isn’t worth it.

Even if the cardboard does not catch on fire, there is still the possibility that it might smoke and burn.

Older ovens have a higher chance of setting cardboard on fire, as the elements are more exposed, and newer ovens reduce this chance quite a bit, as the elements are covered.

You might not ever experience cardboard catching alight in your oven, but just the possibility that it could should stop you from even trying!

1. Chemicals In Cardboard

Some cardboard boxes, especially pizza boxes and takeout boxes, have an anti-grease layer, which helps to prevent grease from leaking out of the cardboard box onto your lap or another surface.

This is a really useful layer to have for takeout and pizza, but it is made from different chemicals or materials like wax or even plastic.

When heated up in the oven, there is a chance that these chemicals might melt or leech into your food, and there really is no telling how dangerous this might be.

If you can feel a coating on the cardboard box you are wanting to place into the oven, it is best to avoid doing so altogether, even though it is never a good idea.

3. Increased Cooking Time

Some foods are designed to be cooked with some paper or cardboard on them, and these would be specially treated to be okay to use in the oven under certain temperatures.

However, cardboard items such as the round base of a store-bought pizza, are not made to be in the oven, and using one could increase cooking time and slow down the rate of cooking.

Using this cardboard base in the oven might prevent the pizza from developing a crispy base, and the base might turn out soggy and just not very appetizing at all.

4. Altered Flavors

Even if you are lucky and the cardboard you have placed in the oven doesn’t catch on fire, there is still the possibility that the cardboard might smoke or burn, or even leach chemicals into your food, and this could change the taste of your food quite a bit.

The ink and chemicals used in the cardboard might become more pronounced when heated, and these odors and tastes could then become a part of the meal you are warming up or cooking, and just completely ruin the overall flavor.

If you want your pizza to taste like pizza, avoid placing it in the oven with cardboard!

Types Of Cardboard

There are many different types of cardboard you might come across that you could need to put in the oven to either cook or warm-up food.

All of these are different, and some might do okay in the oven, while others should not come into contact with heat at all.

Knowing the difference between these types of cardboard, and how they might act in the oven, can help you know when it might be a possibility, and when you should avoid the oven altogether.

1. Cardboard Bases For Frozen Pizza

Almost all store pizzas you buy will come on a cardboard base. For many of us, it would seem that this cardboard base should act as a base for the pizza in the oven, but this isn’t true.

This cardboard base works as a support for the pizza and stops it from flopping all over the place when it is stored at the store, and when you have it at home in the fridge or freezer.

You should not place this cardboard base into the oven along with the pizza, as there is a good chance it will burn and begin to smoke, or even catch alight in more serious cases.

Other than just throwing this cardboard base away, you could use it to slide the pizza into the oven and remove it from the oven once it is cooked.

2. Pizza Boxes

You might be tempted to place a pizza box in the oven to warm up your takeout pizza, instead of transferring each slice to a new dish.

While this might be okay in some circumstances and there may be no fires set in your kitchen, it is still not recommended.

There is no way for you to monitor the temperature of the cardboard pizza box in the oven, and when it reaches a high temperature, it will begin to burn, and definitely ruin the pizza it contains!

Many pizza boxes are also printed, and this printing is done using different inks. These inks will heat up in the oven and might burn quicker, or even transfer an odd flavor onto your pizza.

It is best to just avoid the situation altogether and transfer your pizza to an oven-safe dish to warm it up.

3. Takeout Boxes

Lots of takeout boxes have a grease-proof lining, and this lining is made from different chemicals, which might end up leaching into your food when heated up in the oven.

There is also a chance of your cardboard takeout box catching fire if the temperature in the oven is too high.

It is best to place the contents of the takeout container into an oven-safe dish and heat it up this way instead.

You can be sure that by heating or reheating your food this way, there are no chemicals that are seeping into your food, and it will be safe to eat!

What To Use Instead Of Cardboard

It is easy enough to say that you should avoid placing cardboard in the oven completely, but you still need some type of base or support to heat up pizza, takeout, and other meals in the oven without using cardboard.

Here are some of the options you can use in place of cardboard in the oven:

1. Pizza Stones

A pizza stone is a great option to use in place of a pizza box or cardboard base.

These are usually ceramic or made from stone, and give the pizza an even heating surface that helps to produce a crispy base. The porous base of the stone helps to remove moisture from the dough.

2. Pizza Pans

Pizza pans are often round in shape and are ideal for reheating takeout pizza or cooking store-bought pizza. These are often made from aluminum or something similar, and also help to give pizza a crispy base, cooking it evenly throughout.

Most of these pizza pans either have holes in the base or are perforated, to allow the pizza to cook from direct heat from the bottom, which also helps the pizza cook quicker.

However, this increases the chance that some of the pizza might drip down through the holes.

3. Baking Pans

A baking pan or a casserole dish is ideal to heat up different types of takeout food or ready meals. You can also place slices of pizza into the baking pan and heat them up in the oven this way.

If you do not want to clean up the casserole dish or baking pan after reheating, you can line it with aluminum foil which can be thrown away afterward.

There are lots of different-sized baking pans and casserole dishes, so you can find one to suit your needs best.

4. Baking Sheets

A baking sheet or cookie sheet can be used for just about any food that comes in an oven-safe container, or for a smaller pizza or slices of pizza.

Just like with a baking pan, you can line the baking sheet with aluminum foil so that clean-up is made easier afterward!

5. Aluminum Foil

If you don’t have any other options, you could use aluminum foil to reheat takeout or pizza.

You can simply fold and shape the aluminum foil to suit what you are reheating, and when the food is heated up, you can simply throw the aluminum foil in the trash and not worry about cleaning up.

Just remember that aluminum foil does not offer too much support, so you do have to be careful when transporting the food to and from the oven, especially when it is hot.

6. Straight On The Rack

There are some foods that can be baked directly on the rack, such as ready meals that come in a ready-made container, and possibly pizza, but remember that the pizza might leak toppings down through the rack, and this could be difficult to clean up later on.

Placing food directly onto the rack could also leave grease on the bars, which is another potential fire hazard, and which just dirties your oven over time if not cleaned properly.

This should be your last resort!

Final Thoughts

Even though many people have placed cardboard in the oven and not had a disaster, there is still a big chance that cardboard exposed to the high temperatures in an oven could catch on fire, or even just begin smoking.

The ignition point of cardboard is 427°F, which is easily reached when cooking or reheating food.

There are so many other options available to cook or reheat food, without needing to use cardboard, so it really isn’t worth taking the risk of the cardboard burning or catching on fire!

Related Questions

Can You Wrap Cardboard In Aluminum Foil And Place It In The Oven?

Wrapping cardboard in aluminum foil and then placing it in the oven could still result in the cardboard catching fire, especially when it reaches temperatures of 427°F or higher.

Can I Put A Pizza In The Oven Without A Pan?

You can place pizza in the oven without a pan, directly onto the rack, but this could lead to some of the topping falling down through the racks and onto the bottom of the oven. However, most of the time this should be fine.

Can I Cook Pizza On A Cookie Sheet?

Pizza can be cooked on a cookie sheet, and the crust can still turn out wonderfully crispy done this way. It might not offer up the same results as a pizza stone or pizza pan, but it will still cook well!

Up Next: Can You Microwave Cardboard Safely?

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