Skip to Content

Will Cardboard Burn in the Oven? (Read THIS First)

Will Cardboard Burn in the Oven? (Read THIS First)

It is not safe for you to put cardboard in the oven. Cardboard is combustible, so it can easily catch fire when heated at high temperatures for extended periods.

So, if cardboard shouldn’t be set in the oven, why are there so several claims of people safely doing it without having any issue or whatsoever? Well, there’s one good reason for this.

If you happen to set your pizza in the oven directly on a piece of cardboard, and it’s not getting to be in direct contact with a heating element. Because as the temperature rises in the oven, so does the risk of the cardboard getting ignite. However, it’s not going to ignite as quickly as putting a piece of cardboard on an open flame.

Just have it in mind that for all the claims of people putting cardboard in the oven safely, you’ll find their counterparts that had a kitchen filled with smoke and a few that even started a fire. Again, while it might have turned out just fine for some people, it’s not recommended to put cardboard in your oven.

Even if it had been safe from a fire-safety standpoint, there’s another point to analyze. Many cardboard bases that ship with store-bought pizzas have an anti-grease layer on the exterior part of it. This layer is sure to contain some chemicals that you may not want to have leached into your pizza when it’s heated.

What Temperature Does Cardboard Burn at?

Just as I said earlier on to be on the safer side, don’t put cardboard in the oven. The cardboard has an ignition point of 427 degrees Celsius. Theoretically, if the cardboard stays under this temperature, it won’t ignite. However, there’s still a possibility it will catch fire depending on the type of oven that you have at home.

If the threat of accidental combustion isn’t enough for you, there are many other reasons why you should not put cardboard in the oven.

We’ve also put together a list of alternatives that you CAN simply put in the oven. Let’s have a look…

1. Threat of Spontaneous Combustion

The cardboard can ignite itself if it reaches a very specific temperature of 427 degrees. Most pizzas bake at or above 425 degrees. This two-degree margin could be a little too close for comfort.

If you cook your pizza with the cardboard still underneath it, one or two of the following will surely happen. Either your pizza will be crisp and delicious and nothing will happen. Or, the cardboard will smoke terribly and possibly even ignite from the heat of the oven ruining your night and your pizza.

The type of oven you have can incredibly increase or decrease the possibility of your cardboard catching on fire. Older ovens tend to have these heating elements that are more exposed to the inside of the oven which increases the threat of fire.

On the other hand, newer ovens have the heating elements covered better and circulate the heat making fire less likely. But, to get on the safe side, don’t bother trying to do it.

And, while it’s pretty dubious that your cardboard will catch on fire, the mere possibility of catching something on fire in your house should give you pause.

2. Slows Down Cooking Time

Although you’ll think you’re saving time by leaving the cardboard on your pizza, the precise opposite can be true.

Leaving the cardboard underneath your pizza, or surrounding your food, can slow down the cooking time and keep the underside of your pizza from getting nice and crispy.

However, some things are designed to be baked with the cardboard on. For instance, some frozen dinners have treated paper dishes that are made to resist the heat of the oven.

With any type of paper product that’s not specifically designed for baking in the oven, don’t put it in the oven. Just take the excess time and take it off. The fire department will thank you.

3. Makes Your Food Taste Weird

Even if your cardboard doesn’t completely go on fire, it can still smoke and release fumes. These fumes can put an awful taste on your food as well as make your oven and kitchen smell.

In addition to cardboard, most frozen foods also include plastic packaging to avoid freezer burn. If you don’t remove the packaging and just throw the entire thing in the oven, then that can also create a nasty smell/taste.

The plastic could even melt into your food making it inedible. But, no worries, it’s easy to avoid. Just take all the packaging off.

The small benefits of leaving the packaging on your food don’t outweigh the risks. Unless it’s made to be baked, remove the cardboard and other packaging materials.

Can You Put Cardboard Wrap in Foil in the Oven?

Yes, you can put cardboard wrap in aluminum foil in the oven. You can use it to cook packet S’mores, broil fishes, grill briskets, bake potatoes and even roast delicious turkeys.

They’ll all come out perfect and all done. Just be sure to never use the aluminum foil as a permanent solution to catch spills and drips at the underside of the oven. In other words, it can also affect the quality of baking and damage ovens in the long run.

Just have it in mind that paper ignites at 451 ℉ so in theory, the cardboard would not combust as most cakes are baked at lower temperatures. However, it would be a reasonable idea to cover all sides of the cardboard expose to prevent radiant heat from igniting it and to keep it out of any airflow. Keep in mind that there are also glues in the corrugated board which might likely come out in the heat of the oven.

Can You Bake Pizza on Cardboard in the Oven?

The eating of pizza for any early breakfast is what most people will want to do nowadays before heading out to work or their daily routine. But since the pizza all comes in boxes, most turn to wonder if it’ll be okay to reheat leftovers from last night in the oven without taking the pizza from the box.

Firstly, it’s to understand that pizza boxes are made from hard cardboard paper and hence it can catch fire easily. Putting the cardboard of a pizza in the oven and giving it a short time to heat it, could also be enough to start a fire which will destroy a lot of properties and even lives. The cardboard boxes are only used ​to keep the pizza hot or warm, but not necessarily to be able to heat the pizza in it if it’s cold.

Secondly, heating your pizza in the cardboard box will certainly ruin the taste of the pizza for you. The box is formed out of a lot of procedures and somehow are been exposed to some chemicals which can be inappropriate to heat food in.

The pizza might end up coming out in a bitter taste, with a bad smell or go far as being poisonous. If you’re lucky enough the pizza will come out being half burnt, as in the top part looking all hot and melt with cheese and the bread part being burnt and dark.

A very reasonable way of answering the question can cardboard go in the oven is understanding the temperature levels to heat bread and a cardboard box. The temperature of the pizza will surely be different from that of the cardboard beneath it hence it might catch fire before you notice it.

Since you do not wish to start a fire at your home or workplace, by putting a pizza in cardboard into the oven, you would possibly need to consider other alternatives in heating it. One good method is to buy a non-sticking frying pan or better still a stainless frying pan, place your pizza in it, wait for a minute or two when the underside is crispy.

Cover the frying pan with a lid and leave the pizza to steam for a couple of minutes. This will surely allow the tomato sauce on the pizza to heat up and the cheese to melt and the bottom to remain crispy.

Are Cardboard Boxes a Fire Hazard?

If you are moving to a new home soon, then it is likely that you will want and need cardboard boxes for the task of moving. They are extremely useful in helping you to carry lots of items at once, and they help to protect your things from damage too.

Cardboard packing boxes are great versatile products, that can be used for a variety of different purposes, which include moving, storage and shipping purposes. This means that you can reuse them again and again, and they are recyclable too, so this is another added benefit to the cause.

One thing that many people worry about, is whether cardboard boxes are a fire hazard. Perhaps you are moving home on a very hot day, or you live in a very hot country, or maybe you are storing them in the attic which you know can get very hot at the time and you worry they will catch on fire.

Preventive Measures One Can Take

  • Be Cautious of where you light your Candles
  • Properly Store Flammable Products
  • Make sure your dryers are not close to the cardboard
  • Keep Your Stove and Oven far away from them
  • Test Your Smoke Alarms Regularly to make sure they’re working properly incase a fire might starts
  • Last but not least keep Fire Extinguishers Around

Can Cardboard Catch Fire From the Sun?

No, because the self-ignition temperature of paper is around 480F. That’s the surface temperature required for a light material to ignite without being touched by a flame. The cardboard is less flammable than paper so the temperature required may even be higher.

One factor to consider is the type of binder or glue used to make the cardboard. Even so, the self-ignition point of cardboard to go much lower.

As such, no place on Earth reaches anywhere near 480F naturally due to sunlight. You can only achieve that by concentrating the sunlight with lenses or mirrors.

That said, 480F does exist on Earth, e.g. in the Earth’s interior. You can easily see this when a volcano erupts, where lava is around 1,292F to 2,192F. If you set a cardboard box close to lava, it’ll burst into flames. But that has nothing to do with sunlight so the answer is no.

Are cardboard Boxes Combustible?

It is used as an insulator, but generally, it is used as a packaging material in the form of corrugated cardboard. It is all around us every day but always flammable and possibly dangerous. Cardboard boxes are everywhere.

They can easily burn and also disintegrate from exposure to water, so yes cardboard boxes are combustible.