Publish Time: 2025-04-21 Origin: Site
Learn if it's safe to place pizza boxes in the oven or microwave. Find out about reheating tips for pizza and better, safer alternatives.
Ever found yourself wondering whether you can just toss a pizza box in the oven or microwave to warm your leftovers? You're not alone—and it's more important than you might think. With convenience often trumping caution in the kitchen, many of us shortcut in ways that could be downright deadly. A recent study discovered that warming up plastic food containers in a microwave can release billions of nanoplastics and millions of microplastics per square centimeter—contaminants sufficient to kill human cells cultured in the laboratory.
In today's blog, we're going to take into account whether warming up pizza packages in the microwave or oven is safe, why some materials act this way, and healthier alternatives you can use instead.
Pizza boxes may seem simple, but there's more to them than meets the eye. They are generally corrugated cardboard, which is cheap, light, and a great insulator to keep your pizza warm. Corrugated cardboard is also relatively durable, which makes it good for shipping and takeout.
But as sustainability became more of an issue, new products were created. These include bagasse, a fibrous byproduct of sugarcane juice extraction. So, what exactly is a bagasse product? It is an eco-friendly product derived from sugarcane waste, used to create compostable food containers, including some modern pizza boxes. Bagasse products are biodegradable, resistant to heat, and a more environmentally friendly option than traditional cardboard or plastic packaging.
Baking pizza in the oven seems easy—simply toss the box in and you're good to go, right? Wrong. While it seems easy, cooking a pizza box is riddled with risks and should be avoided in most cases, except if done carefully.
The majority of pizza boxes are made of corrugated cardboard, which is flammable. Cardboard's ignition temperature is around 427°F (220°C). So if your oven gets close to or exceeds this heat, the box may even burn. Even if it doesn't burn, the cardboard has the tendency to smolder, generate smoke, and produce stinky fumes.
Aside from the fire hazard, some pizza boxes have inks, adhesives, or thin plastic coatings that are not food-grade at extreme heat. These, when exposed to heat, leach into your food or release toxic fumes, jeopardizing your health. This is especially alarming if the box has any grease-resistant coating, which usually involves PFAS (per- and polyfluoroalkyl substances), so-called "forever chemicals" due to their environmental persistence and possible health hazards.
If you still like to reheat pizza in the box, there are extremely specific conditions that must be met to minimize risk:
Oven Temperature: Keep the oven temperature below 350°F (175°C). This is far below the incinerating point of cardboard and reduces burning risk.
Time Limit: Never place the box in the oven for more than 10-15 minutes.
Take Out Extras: Make sure you take out any plastic liners, wax papers, or packets of sauce that could be inside the box.
Ventilation: Watch the oven closely and don't leave it running unattended. If smoke is seen, switch it off right away.
All that being stated, it is always best to transfer your pizza onto a baking sheet or aluminum foil before warming it up. You will have the exact same delicious result, albeit without risking your life.
You can absolutely put a frozen pizza directly in the oven—and in fact, that’s how it’s meant to be cooked. Most store-bought frozen pizzas are designed to go straight from freezer to oven, without any thawing. Just preheat your oven to the temperature indicated on the package, usually between 375°F and 425°F (190°C to 220°C).
Be careful not to stack or crowd the oven. Watch the cooking time closely in the last few minutes, as ovens vary and toppings can burn quickly once the cheese starts bubbling.
For the best results, place the pizza directly on the middle oven rack. This allows hot air to circulate around the crust, making it crispier. If you prefer a softer base or want to avoid any mess from melted cheese, you can use a baking tray—but note that it might affect the texture slightly.
Microwaving a pizza box appears to be a fast and easy trick, but it's not always a healthy solution. Before you hit that "Start" button, though, here's something to consider: what really happens when you microwave cardboard, and what does it do to your pizza and your body?
It isn't always a good idea to microwave pizza in the box. Although plain corrugated cardboard may be placed in the microwave for a limited time, pizza boxes may contain more than cardboard. Most have glues, ink, coatings, or grease-proof liners—all of which can emit dangerous chemicals or burn up when they are heated.
Unless the pizza box says "microwave-safe" itself, don't risk it. Look for the microwave-safe symbol (a wavy-lined box) on the bottom or side of the box. If that label isn’t there, transfer your pizza to a plate.
Even when the box is microwave-safe, reheating pizza like this isn't ideal. Microwaved pizza is usually rubbery or soggy, sacrificing its original crispy crust and gooey goodness. That's because the microwave heats food unevenly and steams it from the inside out.
Pro Tip: Want to keep your crust crispy?
Place a microwave-safe glass of water next to the slice while reheating. Steam from the water keeps the pizza moist and prevents it from turning dry and chewy. Reheat for 30 to 60 seconds, depending on your microwave's power, and keep an eye on it so that it doesn't overheat.
If you'd prefer not to sacrifice safety or taste when reheating your pizza, you have some time-tested alternatives that do a whole lot better job than heating the entire box in the microwave or oven.
Using a pizza stone or baking steel in your oven is one of the best ways to reheat pizza. Heat the stone to 450°F (232°C) and place your slice right on it for 5-7 minutes. This will revive the crispy crust and melt the cheese evenly, nearly as if just made from the pizzeria.
Another good and safe alternative is to place your pizza slice on a piece of aluminum foil on the oven rack. Heat the oven to 375°F (190°C) and bake for 8–10 minutes. This gives you a crispy bottom and gooey top without cardboard or plastic contamination.
Need a speedy, crunchy reheat without using the oven? Place your slice in a non-stick pan over medium heat. Cover with a lid to help melt the cheese and heat for 2–4 minutes. Great for small portions and helps keep the crust from becoming soggy.
As we've mentioned earlier, microwaving with a cup of water alongside the pizza has been found to retain texture. Alternatively, simply leave the slice on a microwave-safe paper towel or even reusable microwave tray to avoid sogginess.
Looking for a greener and food-safe alternative to traditional pizza boxes? Our Sugarcane Bagasse Pizza Box is the one you need.
Food Grade Material: Composed of biodegradable sugarcane bagasse that is flexible, strong, and resistant to deformation. So, you don’t need to worry and wonder if sugarcane plates are strong or not.
Good Sealing: Waterproof and oilproof to preserve your food and keep it contained.
Microwave Safe: Resistant to high temperatures without the emission of toxic chemicals or smells.
Safe and Healthy: Bagasse products are hygienic and do not leach harmful chemicals into your food.
1. What's the best temperature for a pizza oven?
When cooking a new pizza, higher temperatures are necessary—475°F to 500°F (245°C to 260°C) being the best. This allows the crust to reach its perfect golden crunch and the cheese to melt evenly. When reheating pizza, though, it's better to lower the oven temperature to around 350°F to 375°F (175°C to 190°C).
2. Can you put cardboard in the oven at 170°F?
Technically, yes—you can put cardboard in the oven at 170°F, since that's way below the temperature cardboard catches fire at (which is around 427°F). But it's not the safest or brightest thing to do, anyway.
3. Is PFAS in pizza boxes?
Unfortunately, yes—some traditional pizza boxes, especially the grease-resistant kind, may have PFAS.
4. How do you reheat pizza without making it soggy?
The microwave is easy, but it usually changes a previously crispy slice into a chewy, rubbery mess. If you have to reheat pizza, use your oven(without the box) or a skillet.
When reheating pizza, taste and safety go hand in hand. Tossing the whole pizza box into the microwave or oven might be an appealing idea, but it isn't always the best—or safest—option. Between the risk of fire, chemical exposure from PFAS, and sacrificing that perfect pizza texture, it's worth taking a minute to heat your slice right.
At Sumkoka, we are experts at offering eco-friendly bagasse products that are ideal for companies that want to minimize their environmental impact. From sugarcane disposable takeout containers to biodegradable plates, our products are created using sustainable materials that are of high quality. If you are in the foodservice sector or want greener options for your company, we have the ideal solution.
Ready to switch to green packaging? Look at our benefits and discover how our products can drive your business forward. Want to sample before you purchase? Order samples now!
Have Sumkoka increase your business with quality, eco-friendly bagasse products. Contact us today and discover our complete line of solutions.
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