Can You Put Cardboard in the Oven?
Can You Put Cardboard in the Oven?

Delicious pizza is a favorite Friday night meal for many people, and we don’t even wonder why – it’s easy to make, even easier to order, or heat up in the oven. In only 15 minutes or less, you can have a delicious meal.

One of the best things about pizza, besides the versatility of its taste, is that it doesn’t require a lot of dishes for preparation and exhausting cleaning. You can order takeout pizza, buy frozen pizzas, whatever your preference is, you won’t be disappointed. Tasteful dough and favorite toppings are a recipe for perfect enjoyment.

Pizza purchased in the store is a quick and cheap dinner that many enjoy. But there is a catch with store-bought pizza. It comes on a piece of cardboard. This piece of cardboard comes in handy when you need to put the pizza in the oven. It’s also great to pick up pizza from the range and cut it, but some people put cardboard in the oven to bake pizza on it.

Can you put cardboard in the oven? Is it safe? Are cardboard pizza boxes adequate to be heated in the oven? Let’s find out.

Cardboard is combustible (flammable), and when exposed to high temperature for an extended period, it could easily burst in flame. So, can you put cardboard in the oven? Shortly, as many people do so, you should never put cardboard in the oven and heat it while baking food.

How is that possible when your friends claim they heat leftover pizza or frozen food in the cardboard box?

Pizza in the cardboard box shouldn't be put in the oven
Can you put cardboard in the oven? Yes, but there are big chances that it will catch on fire (

If you put the pizza in the oven on the cardboard box, you won’t directly expose the cardboard to the heating element. However, the temperature in the oven will rise, and so will the risk of ignition. Cardboard will need more time to burst in flame in the oven than it would on the open flame, but still, you could end up in a kitchen full of smoke and eventually fire.

There is a healthy issue even if we ignore the risk of fire (and why would we?). Frozen pizza cardboard can often have an anti-grease coat on it. When heated, anti-grease coats could leak some poisonous chemicals in your food.

Let’s talk about all these concerns and see is there a better way to bake or warm up your pizza.

Will cardboard catch on fire in the oven?

Yes, cardboard is known for catching fire in the oven. Maybe it won’t ignite instantly, but heated at high temperatures for an extended period, cardboard can burst in flame.

Manufacturers of cardboard boxes often use cardboard with a paper structure, igniting even at low temperatures.

To be safe, avoid putting cardboard boxes in the oven and instead use a baking pan, cookie tray, casserole dish, pizza pans, or other.

Can cardboard go in the oven on warm?

Cardboard pizza box can go in the oven to stay warm but at a shallow temperature. It would be best if you never put cardboard in the oven at high temperatures – it could quickly go on fire or release toxic chemicals in your food.

At what temperature will cardboard catch fire?

Cardboard has an ignition point of 427 degrees Fahrenheit, so theoretically, if you keep the cardboard in the oven at temperatures below 427 degrees, it shouldn’t ignite.

Cardboard boxes can ignite at lower temperatures, depending on your oven type.

Cardboard underneath pizza is flammable
Cardboard underneath frozen pizza is flammable (

If you have to heat frozen foods or pizza boxes, which we do not recommend, heat them at temperatures lower than 400 degrees Fahrenheit.

However, do not heat pizza boxes for safety concerns and do not put cardboard in the oven.

Can cardboard spontaneously combust?

Spontaneous combust happens when some flammable material, out of nowhere, bursts in flame. It’s a chemical reaction that occurs under certain conditions.

“Spontaneous combustion is a runaway temperature rise in a body of combustible material that results from the heat being generated by some process taking place within the body,” – according to the Handbook of Fire Prevention Engineering.

Cardboard can spontaneously combust when exposed to carbon-based animal or vegetable oils, such as cooking oil, corn oil, lard, or margarine.

Is heated cardboard toxic?

Chemicals from ink print can leak into your food and make it unsafe to consume. Cardboard containers often have a glue, wax coating, or ink print which can be dangerous when heated up with frozen foods. Also, your food could taste weird when heated or baked in cardboard.

What is the purpose of the cardboard in pizza packaging?

Cardboard base in typical store-bought pizza has a protective role.

Store-bought pizzas (as well as other frozen foods that come on corrugated cardboard) are delicate when they’re frozen, and the cardboard base prevents its damaging, keeping pizza crust and toppings in one place.

Pizza cardboard keeps pizza's delicacy
The purpose of cardboard underneath is to keep pizza’s delicacy (

In addition, most cardboard bases have an anti-grease layer on top that stops cardboard from absorbing grease and breaking. This cardboard base is excellent aid from the way from the store to your kitchen, but when it comes to heating and baking pizza, avoid putting the cardboard bases in the oven, as they could potentially catch fire.

Does cardboard keep heat out?

Yes, cardboard keeps heat. Cardboard has a lot of layers, and between every layer, it has air pockets that “trap” the heat that come inside the cardboard. Food kept in cardboard can maintain heat for a specific time.

Will a cardboard pizza box catch on fire in the oven?

It is not safe to put cardboard of any kind, including a pizza box made of cardboard, in the oven.

The highest temperature pizza box can take 400 degrees Fahrenheit. All above that will make the cardboard box burst in flame. In some cases, even lower temperatures will induce the same effect.

We’ve mentioned above that some people like to keep their pizza warm by keeping it in the box, at low temperature, in the oven.

This practice is not safe, and it could require the intervention of firefighters.

How to keep pizza warm in its box?

Instead of putting the pizza box in the oven to keep it warm, you can use aluminum foil.

Wrap the entire box in aluminum foil and seal it from every side. Make sure there are no holes that can release heat. Aluminum foil is an excellent heat isolator, and it will keep your pizza warm for at least an hour.

When you’re wrapping the pizza box in aluminum foil, it’s the same as if it is a shiny or dull side of the foil. Both sides retain the heat equally well.

Can you put a pizza in the oven by itself?

You can bake pizza directly on the oven rack, but only if it’s store-bought frozen pizza, pizza with premade crust, or already baked pizza that you’re reheating.

Dough that you just kneaded should never be put on the rack, as it’s too soft and it could easily fall through the wires.

Putting soft pizza directly on the rack will not only make a mess in your oven but will also ruin your meal.

What to use for baking pizza in the oven instead of cardboard?

There are other methods of cooking pizzas or reheating pizza slices that do not include using cardboard. If you’re baking a store-bought frozen pizza, follow instructions on its packaging.

You can easily cook or reheat pizza on the grill
You can quickly cook or reheat your pizza on the grill (

If you’re reheating the leftover slice, put it in the oven at 350 degrees Fahrenheit.

Bake pizza directly on the oven rack

If you have frozen store-bought pizza on your hands, you can bake it directly on the oven rack.

Freshly knead pizza dough could be too soft for the oven rack, and it could fall through, but if you have some aluminum foil, that problem will be easy to solve.

Bake pizza on aluminum foil

Aluminum foil is a cheap alternative to pizza pans, cookie sheets, and baking pans.

If you don’t have any of those dishes, take the rack out of the oven and wrap it in aluminum foil before you preheat the oven. Aluminum foil is tin foil made out of thin metal, and it will successfully imitate baking pans. It’s perfect for baking food.

You will evenly cook your pizza from all sides; it will have a crispier crust and be delicious as always. In addition, aluminum foil will prevent dripping, and it won’t make a mess in your oven.

Bake pizza on the pizza stone (baking stone)

Pizza stone or pizza block is an excellent investment if you often bake pizzas. A pizza stone is a specially made ceramic sheet that you put directly in the oven to bake pizza.

You can use pizza block and pizza stones to make most frozen foods and pizzas, producing pizzas with even crispier crust and great taste.

Baking pizza on a cookie sheet is one of the most recommended methods. Cookie sheets are made of thin metal that distributes heat equally, so they will evenly cook your pizza. You’ll also get the crisp bottom and crispy crust when you cook pizza on a cookie tray.

Bake pizza on a cookie sheet
Bake pizza on a cookie sheet (

A cookie sheet (baking sheet) is an excellent option for other frozen food. Your food won’t catch fire, and you won’t have a problem that food tastes weird, like when it’s heated in cardboard packaging.

Baking pizza on a baking pan

A baking pan or a casserole can be a great alternative if you don’t have a cookie sheet. If they’re big enough to place pizza) they will make your pizza cook the same way it would on a cookie sheet, but without toppings falling.

How to reheat pizza without using the cardboard?

If you have left half of the pizza or one or two slices, you can reheat them without cardboard.

Reheat pizza in the oven

Reheat your pizza in the oven, but don’t put cardboard packaging in it. Instead of cardboard, put pizza on the baking stone or cookie sheet and place it in the middle oven rack.

You should preheat your oven to 350 degrees Fahrenheit. Pizza crust will be crispy, and toppings will melt and have a perfect texture. Ten minutes should be sufficient to warm up pizza in preheated oven.

Reheat pizza in the microwave
Reheat pizza by microwaving it (

Reheat pizza in the toaster oven

You can reheat your pizza in the toaster oven, following the same procedure as the regular electric oven. Reheat your pizza at a higher temperature for a shorter amount of time, and your pizza will be perfect every time.

Reheat pizza in the grill

Grill reheating methods include preheating your grill for a few minutes until it’s hot. Put pizza on the grill directly, close the lid and let pizza heat for 5 minutes. Remove pizza and put it on an upper grill for additional 5 minutes. Your pizza will be perfectly hot, the cheese will melt, and the crust will be perfectly crispy!

Reheat pizza in the microwave

It’s possible to reheat leftover pizza in the microwave too. When microwaving pizza, first make sure that your microwave is wide enough for a pizza slice. Fill microwave-safe bowl 2/3 with water and put on the microwave-safe plate with pizza. Water will prevent the pizza from becoming stiff and dry during reheating.

Microwave at half power for about a minute. Check on your pizza and if needed, reheat it for a minute more.