Can Cardboard Go in the Microwave? (Amazing Answer)

So, you have yesternight’s leftovers that you want to warm in the microwave. You want to use cardboard but are worried because you don’t know how safe it is to use it in the microwave.

Do you use the cardboard or not?

Well, cardboard is usually considered an easy and fast way to start a fire. It’s no surprise that you are worried about placing it in the microwave.

The answer to whether cardboard can go in the microwave is both yes and no. This is because it’s safe to microwave cardboard in some instances and unsafe in others.

As the microwave heats your food, it causes the water molecules in your food to vibrate faster. This process creates friction and heat, which cooks the food.

And since cardboard has little moisture, there aren’t a lot of molecules to move around. It, therefore, doesn’t get as hot as your food. This makes it safe to use it in the microwave.

The danger occurs when the inside or exterior coating of the cardboard is heated. It can not only ignite when exposed to extreme heat but also cross-contaminate your food with potentially harmful chemicals.

How Safe is it to Microwave Cardboard?

It is safe enough to microwave a cardboard container if it’s made of pure cardboard. Such a container won’t damage your food or the microwave.

Can Cardboard Go in the Microwave

Note that some cardboard containers contain chemicals that can leach into your food. You don’t want to ingest the hazardous chemicals, right?

Avoid using cardboard containers that contain plastic, glue, wax, or metal coating.

Always check the label on the cardboard to ascertain whether it’s microwave safe or not. These containers will have the label if tested by the manufacturer.

To be on the safe side, never overheat a cardboard container.

Can you Microwave a Cardboard Takeout Box?

You can microwave a cardboard takeout box if it doesn’t have metal handles, not lined with plastic, wax, or glue.

Check the microwave-safe label on the cardboard box as well, just to ensure that the box is indeed microwave safe.

Also, since cardboards have very low moisture, they don’t heat up fast. This means that the box will be safe to use in the microwave if you don’t intend to microwave it for too long.

Is it Safe to Microwave Cardboard Paper Plates?

Paper plates come in handy when hosting guests or when you just don’t want to clean dishes after dinner. But is it safe to microwave cardboard paper plates?

Cardboard paper plates are safe to use in the microwave if they don’t come with any plastic or wax coatings.

These plates have low moisture levels hence won’t overheat or burst into flames in the microwave.

Will Cardboard Burst into Flames in the Microwave?

We all know that cardboard is a good conductor of heat, so yes, it can easily catch fire when exposed to high temperatures in the microwave.

If using a cardboard box made from pure wood fiber or pulp without additional materials like metal, you’ve got no reason to worry. Such are usually safe to use in the microwave.

If the box has small metal elements or plastic coating, avoid using it in your microwave at all costs, as it can be dangerous.

Another important point to note is that you should never microwave cardboard for long. Prolonged heating increases the chances of catching fire due to overheating.

Remember that although cardboards contain moisture (9 to 12%), the moisture level starts to drop when you microwave it.

Should the moisture drop to 1% or below, the cardboard will be completely dry and can catch fire.

How Long Should You Microwave Cardboard?

As aforementioned, you should never microwave cardboard for a long time. Microwave it to shorter periods of 1 to 2 minutes at the most.

If you intend to microwave it for more time, do it in intervals of 30 seconds to a minute. At no time should you exceed the heating time for more than 2 minutes.

Tips to Microwave Cardboard

The following tips will help you microwave cardboard safely:

  1. Ensure to check the label before microwaving the cardboard. If it doesn’t have the label, it simply means that the manufacturer didn’t test it for microwave safety, therefore avoid it at all costs.
  2. Check the cardboard to ensure it isn’t coated with wax or plastic. The 2 elements can be hazardous when they come into contact with heat.
  3. Remove metal, paper, or plastic pieces before microwaving the cardboard.
  4. Don’t microwave the cardboard for long periods; instead, do it for 60 to 90 seconds intervals.
  5. Always check the settings of your microwave and set it to the lowest possible level when heating your food in a cardboard box. This helps prevent fires that result from overheating.

Frequently Asked Questions

Q. Is it safe to use McDonald’s cardboard boxes in the microwave?

Yes, you can microwave McDonald’s cardboard boxes since they come with metal attachments. They also don’t have plastic or wax coating hence safe to microwave.

Q. Can I reheat food in a cardboard box?

You can reheat your food in a cardboard box but for a limited period. Prolonged heating can lead to overheating and cause a fire.

Q. Can you microwave a cardboard pizza box?

While some cardboard pizza boxes are microwave safe, others are not. Always read the manufacturer’s information on whether the box can withstand the heat or not. If it can’t, don’t place it in the microwave.


Microwaving cardboard is safe if you follow a few key rules. Ensure that the cardboard doesn’t have dye or glue that can leach into your food. It should also be free of plastic or wax coating as these can be dangerous.

Microwave the cardboard for short periods or intervals to avoid overheating. Also, ensure that the cardboard doesn’t have any metal parts before placing it in the microwave.

It’s also important to check for the microwave-safe label on the cardboard. If it has the label, feel free to use it in your microwave.