Can You Microwave Cardboard

can you microwave cardboard

After a long day at work, you want a leisurely dinner, and luckily, there’s some leftover takeout in the fridge. But can you microwave cardboard? You can probably do it without any issues. Still, it’s wise to take a few extra seconds to ensure the container is made of safe material to keep your food and Microwave in good condition.

Is It Safe to Microwave Cardboard? 

If you have safe cardboard in the Microwave (made of only cellulose), you can heat your food for short periods, but not more than 60 to 120 seconds. It’s also important to check the cardboard every 30 seconds to ensure it doesn’t overheat. Remember also to set your Microwave to a low power setting.

However, if you need to heat your food longer, transferring it to a different microwave-safe container is better. This is because cardboard can easily catch on fire if it gets too hot, especially if exposed to temperatures over 400°F or heated for a long time. This happens because the cardboard’s moisture evaporates, making it more flammable.

Can a Pizza box go in the Microwave?

When it comes to reheating pizza in the Microwave, the box it came in is usually safe to use as long as you check for a label or instructions that say it’s microwave-safe. Some pizza brands make boxes that can be reheated in the Microwave, but some may have plastic or metal parts that can’t be microwaved.

If you decide to use the pizza box, ensure it’s in the Microwave for less than a minute to avoid any issues. But honestly, there are plenty of other tasty ways to reheat your pizza!

Types of cardboard you can’t Microwave

There are certain types of cardboard containers that you shouldn’t use in the Microwave. These include:

  • Cardboard with glue or adhesive, which can release chemicals into your food
  •  Cardboard with ink printed on it, which can also release chemicals into your food
  •  Cardboard with a wax or plastic lining can release chemicals and fumes into your food.
  •  Takeout containers with metal handles, like those used for Chinese food, should not be microwaved because metal can cause problems in the Microwave.

By the way, if you’re wondering whether you can microwave paper plates or use glass in the Microwave, we’ve covered you in separate articles!

Tips for Microwaving Cardboard

When using a cardboard container in the Microwave, ensure it has a microwave-safe label. If it doesn’t have one, transferring your food or drink to another microwave-safe dish before heating it is best.

It’s essential to have food in the container, as this helps absorb the microwaves and reduces the risk of the cardboard catching fire.

To reduce the fire risk further, you can line your container with a paper towel or napkin to soak up any oils. This will help prevent the cardboard from heating up too quickly.

Finally, keeping an eye on your food in the Microwave is essential. Please don’t leave it unattended; heating cardboard in the Microwave can be risky.


What happens when you microwave cardboard?

Some cardboard can be harmful to your food if you microwave it. For example, cardboard with glue or ink printed on it can release chemicals into your food. Cardboard with a wax or plastic lining can also release harmful chemicals and fumes. It’s important to avoid using these types of cardboard in the Microwave.

Can I put cardboard in the oven?

It’s not safe to put cardboard in the oven. This is because cardboard can catch fire easily. The cardboard will ignite or catch fire if the temperature gets too high. The ignition point for cardboard is around 427 degrees Fahrenheit. So, never putting cardboard in the oven is essential to avoid fire risk.

Also read: Is Pyrex Oven Safe?