Microwaves are handy appliances capable of heating almost everything, from leftover pizza to hot pockets to burritos. They’re convenient, fast, and easy to use.
However, can you microwave cardboard?
Yes, cardboard can be heated in the microwave, but only under certain conditions and close supervision. For starters, ensure that your cardboard of choice is microwave-safe.
Also, avoid using cardboard containers with metal, plastic, foil, or wax coatings, as these materials may warp, melt or catch fire during microwaving.
The following post will examine what makes cardboard microwaves safe and offer a step-by-step guide to cooking with cardboard in your microwave. Furthermore, we will discuss some potential safety concerns and precautions that must be followed when microwaving food in cardboard containers.
What Is A Cardboard?
Before you decide if it is possible to microwave cardboard, you should first know what cardboard is.
Well, simply put, it’s a heavy-duty paper product made of thin layers of corrugated fiberboard. The size and weight of each layer vary, which affects its strength and stiffness.
Cardboards have become an integral part of modern packaging in recent years due to their low production costs and ability to protect from impacts. They have been replacing plastic and foam packing materials, as they are more eco-friendly and recyclable.
The most widely used type of cardboard is single-wall corrugated fiberboard. It features a flat sheet of paper wrapped with one layer of corrugated fibers and comes in various thicknesses and sizes.
What Qualifies A Cardboard Safe For Microwave?
As we stated at the outset, it is critical only to use microwave-safe cardboard. But are you aware of what makes microwave-safe cardboard effective? What makes it better than its alternative – plain paper, for example?
Well, read on to find out about five of these essential qualities.
1. Labeled Microwave-safe
One of the essential features to look for when purchasing a cardboard box is an easily visible label indicating safe use in microwave. Such labels can be found either on an interior or exterior surface, but there should be no doubt about their presence.
If such a label does not exist, likely, you don’t have your desired item. The label eliminates instances where you unknowingly use potentially dangerous containers. As a result, it saves you time and money and prevents damage caused by improperly used microwaves.
2. Moisture Resistance
When microwaving food, moisture is often an issue. Food is typically wrapped or covered in some manner to help keep it dry during cooking. But what happens when there’s too much moisture? How do you keep your food from being soggy?
The best materials to use for microwave-safe cardboards should resist liquids. This way, you can cook your food quickly and safely without fear of issues due to excess moisture. In most cases, simply using an absorbent material will do just fine.
3. Heat Retention
Heat-resistant is crucial for any microwave-safe cardboard since it will be exposed to heat. Your cardboard should withstand temperatures between -20 degrees F and 446 degrees F without warping, melting, or becoming soft.
This also applies to cold applications such as frozen foods. Make sure your cardboard won’t become brittle in these conditions, which would cause breakage when exposed to microwaves.
It’s also important that your package maintains its intended structural integrity when frozen. Otherwise, it could develop cracks that could let steam escape during microwaving, and you may end up with wet foods rather than crispy ones.
4. Stiffness
If a container is soft and flexible, it will bend and collapse in on itself. This can be very dangerous for food because if you place hot food in that kind of container, it can lead to splatters all over your microwave.
A stiffer container that holds its shape is better for microwaving. It also means you don’t have to use as much foil to protect yourself from spatter when you heat your leftovers. Better protection allows for more heating without fear of damage.
5. FDA Approved
The FDA is a potent government agency that oversees what we can and cannot consume. While it’s impossible to be 100% sure, anything you put in your microwave will most likely have to pass through their approval process before going to market.
Fortunately, their website contains thousands of documents (both online and PDF) on everything from pesticides to food additives. If you’re wondering if something is approved for cooking, it’s probably worth Googling FDA + Product Name to see if it’s listed on their site.
With that said, there are countless products out there with questionable safety records, so when in doubt, it’s best to err on the side of caution.
Types of Microwave-safe Cardboards
It is pretty essential to know that not all materials are microwave safe. To put it mildly, some emit toxic chemicals when exposed to extreme heat. That’s why you should replace them with other kinds of food packaging products.
So, here are some commonly used microwave-safe cardboards:
- Heavy-duty Paper cups
- Pizza boxes
- Sectioned food bowls
- Recyclable plates
How to Safely Microwave a Cardboard
When most people think of microwaving food in cardboard, they imagine their kitchen going up in flames. The truth is that it is perfectly safe to do so, as long as you follow several simple steps with minimal cleanup afterward.
- The first step is to place empty cardboard on a microwave-safe dish. Make sure it is dry and foldable to be easily placed inside the microwave.
- Secondly, you should fold your cardboard in half to ensure no hot spots form when microwaving.
- Thirdly, place any food you wish to heat up inside your folded cardboard.
- Fourth, turn on your microwave for about 5 minutes at full power until the food reaches the desired temperature.
- And last but not least, remove from oven with tongs or oven mitts and let cool before eating.
How Long Does It Take To Heat a Cardboard?
Cardboards should not be heated for longer than 120 seconds, as they melt very quickly or catch fire. It is recommended that you heat your cardboard in intervals, allowing it to cool down before reheating again.
For instance, a 30 or 60-second interval will guarantee a safe and effectively warmed meal with minimal microwave usage.
Check for the safety label before heating your food to ensure your cardboard is microwave safe.
Safety Tips to Microwave a Cardboard
People are increasingly eating food out of cardboard these days. It’s an efficient and environmentally friendly way to pack your lunch. However, you should follow these six tips for safety reasons when microwaving your cardboard.
1. Read Microwave’s Owner’s Manual
Before turning on your microwave, always make sure to read its user manual. These instructions are usually located inside or on top of your appliance. Some microwaves may have different instructions, so you must pay close attention.
After reading all instructions and safety precautions, unplug your microwave and move on with your cooking.
2. Only Use Cardboard Microwave-Safe Labelled
Some cardboards are safe for microwaves, and others are not. Only use sturdy cardboards, which are FDA-approved as a food container. After all, you wouldn’t want your microwaved meal contaminated with toxic chemicals that can leach into your food. Always look for labels indicating microwave-safe or microwavable.
3. Microwave the Cardboard for No Longer Than 2 Minutes
Since cardboard is made of paper, it can easily catch fire in a microwave. You should put it into the microwave for less than 2 minutes.
However, if you want to microwave your cardboard for an extended period, take short intervals of time, such as 10 seconds, before repeating the process until 2 minutes are completed.
4. Never Microwave Metal
Metal can cause sparks or fires when placed in microwaves. So don’t microwave tin foil or any container with a metal rim or handle. Only use cardboard that is microwave-safe, like plastic and ceramic dishes.
5. Use Thick Cardboard
Not all cardboards are created equal. If you want to microwave your cardboard, you’ll need something thick and sturdy. Otherwise, it may get too hot and catch fire in your microwave.
Use some thick sheets of cardboard or corrugated fiberboard. Also, remember that microwaves tend to heat their contents unevenly, so don’t load up more than one layer of material in your oven.
6. Check To See If It’s Waxed or Plastic-Coated
If your cardboard is waxed or plastic-coated, heat will likely cause it to melt in your microwave. Before microwaving your cardboard, ensure it’s not waxed or plastic-coated.
To do so, hold it up to bright light and look for any coatings on its surface; if there are no visible coatings, then it’s safe for the microwave. However, if there are more layers on top of your cardboard, use an old razor to slice them away carefully.
Faqs About Can You Microwave Cardboard
1. Can you heat up food in cardboard?
Yes. In fact, you can microwave cardboard – and it will heat up just like any other food container. However, to be on the safe side, be sure that you are using cardboard boxes intended for the microwave.
Additionally, reheating must be done at frequent intervals (e.g., 30 seconds). If you overheat your cardboard for more than 2 minutes, it may catch fire or even explode.
2. Can you microwave a cardboard pizza box?
Yes, it is safe to microwave a cardboard pizza box. This is because it is made from cardboard which is generally safe for use in a microwave. Just remember to take the same safety precautions you would with any other food container.
3. Will a box catch on fire in the microwave?
It all depends on how you microwave it. In general, cardboard doesn’t burn unless heated for an extended time or enough oil or fat is present to ignite it. To prevent an inferno, permanently remove any liquids (coffee cups and plastic bags, for example) before heating them in a microwave.
4. Can you microwave Chipotle cardboard?
The majority of Chipotle packaging is not microwave-safe. It includes harmful chemicals that may find their way into your food, causing health problems and discomfort.
5. Are cartons microwave safe?
All cartons made of pure wood pulp and paperboard are microwave safe. However, if they have plastic coatings or metal components, they may not be microwave safe.
If you have any doubts regarding your cardboard box being safe for microwaves, it is always better to double-check with your manufacturer before proceeding further.
6. Are KFC boxes microwavable?
Yes, KFC boxes are microwave safe. KFC boxes are typically made of cardboard and then lined with tin foil for extra durability and heat protection. Many other fast-food chains also use cardboard for packaging their foods; they are all safe for microwave use.
Bottom Line
As it turns out, you can microwave cardboard, but you should take extra caution when doing so. If you’re looking to zap some cardboard in your microwave, following some simple guidelines will ensure your safety and protect your microwave from getting damaged.
For example, most cardboard will ignite at high temperatures when heated for a prolonged period. As a result, microwaving should be kept to brief time intervals and always on low power settings. You should take the same precautions while using waxed cardboard containers, which are more flammable than uncoated cardboard.
And with the above safety tips, you won’t have to worry about damaging your microwave or being exposed to dangerous chemicals by microwaving cardboard.
