Oven Temperature Cardboard burns at approximately 450 degrees Fahrenheit. Since the general consensus for reheating pizza in the oven is to keep the temperature set to 350 degrees Fahrenheit it should be safe to leave your pizza in the box, however, you must be extremely vigilant while it is baking.
It is never safe to put cardboard in the oven. Although some people may have purposefully or accidentally placed cardboard in the oven without it catching fire, it is never advised to do so.
Turn your oven to the lowest heat possible – typically 170 degrees Fahrenheit. Then, simply place the box inside the oven. The low heat creates a climate similar to an oven inside the pizza box. The cardboard will not catch on fire unless the temperature exceeds 400 degrees Fahrenheit.
No, you should not put a cardboard pizza box in the oven. Cardboard can catch fire and create a fire hazard in the oven. If you want to heat the pizza, place it directly on an oven tray or an oven-safe plate.
Set the oven temperature to 275 degrees. Let the pizza warm until bottom is crisp and cheese has melted, 25 to 30 minutes.
According to research by the Smithsonian Institution, cardboard can ignite at temperatures between 425-475°F if exposed to heat. Most 24 inch electric wall ovens easily reach over 500°F when set to standard baking temperatures. This intense heat can cause cardboard to rapidly ignite inside the confined oven space.
If you're using microwave-safe cardboard (meaning cardboard that is pure cellulose), then you can microwave it for short periods of time. Just keep it between 60 and 120 seconds, and check every 30 seconds to reduce the risk of overheating the cardboard. Keep your microwave on a low power setting, too.
But again, please don't! Cardboard boxes, aside from being fire hazards, can release toxic fumes when heated. Many pizza boxes have printed designs or coatings that aren't food-safe when exposed to oven temperatures. Even if the box is plain cardboard, the risk of it catching fire or emitting harmful chemicals is high.
Cardboard doesn't catch fire until temperatures reach over 400 degrees. But to be safe, we recommend you keep your heat at the suggested setting of 170. If you want to crank it up a bit more, that's fine. Just keep it under 300.
Yes, aluminum foil is ideal for oven use. Aluminum foil is safe and convenient and helps reflect heat to enable your food to cook evenly. It also withstands the highest temperatures in most home ovens, making it an excellent choice for baking and cooking.
Once your pizza is wrapped, put it in the oven at around 200 degrees Fahrenheit and heat it for 15 minutes. Once you take the pizza out, keep it wrapped in the foil and it can stay hot for up to three hours.
Oven rack: If you don't have a baking tray or stone, and you prefer a crispier crust, you can bake the pizza directly on the oven rack. Place a sheet of greaseproof paper underneath to prevent the dough from sticking.
Cardboard's ability to trap heat
Another brilliant effect of cardboard as an insulator is that heat can be trapped as well.
Oven Temperature
Cardboard burns at approximately 450 degrees Fahrenheit. Since the general consensus for reheating pizza in the oven is to keep the temperature set to 350 degrees Fahrenheit it should be safe to leave your pizza in the box, however, you must be extremely vigilant while it is baking.
Paper and Cardboard
While extreme heat doesn't affect cardboard directly, it raises the internal temperature of the packaging and puts products at risk of melting or experiencing other damage. Extreme cold affects adhesives and can cause the glue holding the box together to fail.
Some pizza boxes have microwave-safe labels and instructions written on them, so be sure to check the box for these before reheating the pizza. Keep the reheating under one minute and check on the box after the first 30 seconds. It would typically take a temperature higher than 400°F for the box to burn.
In Your Oven
There are two ways you can keep your pizza warm in the oven: In the box: Don't panic! Pizza boxes won't catch fire until they reach over 400 degrees. For this method, set your oven at the lowest temperature and slide your pizza, still in its box, onto the middle rack.
Unfortunately, cardboard can contain glues, waxes and other materials that can make it a safety hazard in the microwave. Some cardboard takeout boxes even have metal handles or fasteners that can cause sparks and present a fire hazard.
Top pizza on parchment paper and transfer topped pizza and parchment paper into pre-heated oven directly onto the oven rack. Please note: Make the pizza on the parchment paper and transfer it into the pizza box and slide the pizza with the parchment paper directly into the oven.
Step 1: Pre-heat oven to 325 degrees Fahrenheit. Cover baking sheet with a layer of aluminum foil. Arrange pizza slices on the tray so crust is flat against the foil. Step 2: Bake for 10-15 minutes, depending on crust thickness.
A bit of butter in a medium hot skillet (with a lid) will crisp up the crust to a lovely texture, add a buttery goodness to the crust and re-melt the cheese while warming your toppings. I do this all the time and it's the best “leftover” tasting pizza ever!