Can You Microwave Cardboard? Is It Safe?

Can cardboard-contained food be reheated or microwaved? Sometimes we buy takeout and there are leftovers from that portion, and instead of warming it in a microwave-safe plate, you wonder if you can microwave it in the container, the food came in. 

Typically, meals are to be reheated in a microwave-safe container or paper plate. However, it would be convenient if we can reheat meals in the container they came in, which leads to curiosity; is it safe to microwave cardboard container foods?

Yes, you can microwave cardboard containing food or drinks. This should be done under supervision, on low heat, and for 20 seconds intervals, until you reach your desired temperature. For safety purposes, it is best not to microwave cardboard containing plastic, wax, ink, glue, or metal, unless the labeling species otherwise. 

Although it is good to test run, things we haven’t done before, it is advised not to microwave empty cardboard (devoid of food or drinks) containers, to avoid overheating. With this in mind, this article would discuss how to safely microwave cardboard-contained foods.

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Using the microwave
Image: Envato Elements

Is It Safe To Microwave Cardboard?

Although cardboard-contained takeout or foods are considered generally microwave safe, there are a few things to bear in mind, when you plan to microwave cardboard or reheat a cardboard-contained food. 

Firstly, you need to confirm that the cardboard container in question is microwave safe. Always start by checking the labeling, if the particular container is considered microwaveable, and solely use containers that are considered so. 

This is because cardboards are often made from recycled materials, and the cardboard container in question may be recycled from materials that are not microwave-safe, such as metals. With this, if such isn’t stated in the labeling, confirm from the manufacturer’s website, if the container is regarded as microwave safe.

Also, do not microwave cardboard as a stand-alone or empty. This simply means your cold or excess food or drink should be inside the cardboard container when reheating, as empty cardboard when reheated absorbs heat, making it flammable. 

Can You Microwave Cardboard? Is It Safe?
Source: Can you microwave this?

As mentioned above, refrain from microwaving cardboard that contains metals, ink, wax, glue, or any recycled material that is considered not microwave-safe, as this could lead to the cardboard box catching fire.

Additionally, should in case the cardboard catch fire when reheated, remove the box from the microwave and use a fire extinguisher or baking soda. Do not pour water on flaming cardboard, this could lead to increased fire. 

How to Safely Microwave Cardboard

Now that all safety precautions have been discussed, let’s highlight how to microwave cardboard meals using five easy steps; 

Step 1

Check that the labeling instructs the use of the particular cardboard container. This means be sure that the cardboard container you want to reheat, is microwave safe.

Step 2

Second, ensure that the cardboard container is completely dry before microwaving or reheating it. If it was refrigerated or frozen, allow it to thaw for some time and clean any excess liquid before microwaving. 

Step 3

To make the heating process easier, carve up the cardboard to fit into the style and size of the microwave you own at home, then place the cardboard container on a plate or bowl to catch any sparks or flames. 

Step 4

the cold or leftover meal should be reheated in the microwave for a short period under supervision. This is to avoid the cardboard, absorbing too much heat and catching fire. Start with 20-30 seconds on low heat, until you reach your desired temperature. 

using the microwave
Image: Envato Elements

Step 5

Always be present and monitor the process, when microwaving a cardboard container

Frequently Asked Questions

Can you heat food in a cardboard box? 

Yes, you can reheat food in a cardboard box, however, you must do it for a short period under supervision. This simply means reheating has to be done for a limited time.

Can I microwave Chinese takeout boxes?

Yes, you can microwave glass, ceramic, and containers with a waxy finish. This also includes Chinese takeout containers but remember to remove the metal handles before microwaving.

Does cardboard explode in the microwave?

It is dangerous to microwave cardboard empty or by itself. Also, if moisture is on the cardboard and is heated up and then drys out for a long, you can end up with a steam explosion.

Is McDonald’s cardboard microwaveable?

Yes, generally you can microwave McDonald’s cardboard containers and boxes. Food must be inside the cardboard when reheating, and this should be done under supervision. 


There’s an easy convenience and smart packaging that comes with heating meals in the container they came in, this way if you’re going out or going to work, you can carry it along, rightly packaged as well.

Hence, the curious question is if food can be microwaved in its packaging or in a cardboard box. 

This article has helped to discuss that you can microwave cardboard containers, however, it should be for a short period and to avoid microwaving cardboards containing wax, plastic, metals, or ink.