Whether it be sheets of paper, a book that got wet, paper towels or paper plates and cups there can be lots of situations where you might want to put paper in the microwave.
But given that paper can catch on fire easily you may be wondering can you microwave paper?
It's a good question to ask, not just because of the fire hazard but also because paper can, surprisingly, contain chemicals that are harmful to humans.
It is safe to microwave paper when the paper is lying flat, however you should always watch it closely. This includes sheets of paper, paper towels and paper plates/cup. However, when scrunched up paper can easily combust in the microwave and set on fire.
There are also so health risks with microwaving food or drink in/on paper. While harmful chemicals like BPA and styrene don't seem to leach into food or drinks from paper the bleaching process to make paper white can create toxic chemicals called dioxins which are a probably human carcinogen.
We'll look into more detail about the health risk associated with food and paper later. For now let's have a look at what happens when you microwave paper and in what situations paper will set on fire.
What Happens When You Microwave Paper?
There isn't much online about exactly what happens to paper when you microwave it. Under what conditions is it fine to microwave it and can you actually set paper on fire in the microwave?
So I decided to go ahead and run some experiments myself. I microwaved some white paper as well as brown paper bags. I tested them lying flat in the microwave and then also tested them scrunched up and waited to see if they would catch on fire or what would happen.
As you can see in my video below I was able to set the paper on fire when it was scrunched up:
Here's what I discovered about what happens to paper when you put it in the microwave:
When you microwave flat paper it gets extremely hot, above 100ºC (212ºF) but when lying flat it's unlikely to catch on fire. However when it's scrunched up it can get hot enough in sections to set the entire thing on fire.
As soon as you turn off the microwave the paper starts cooling down extremely quickly. This fact is important if you're looking to microwave paper for a while.
Multiple bursts are much safer than extended periods of time in the microwave.
This holds true for sheets of paper, paper plates and cups as well as paper towels and even cardboard.
So if you're looking to microwave paper you'll want to keep it as flat as possible
Can You Microwave Sheets of Paper?
Maybe you've wet an important paper, drenched a book by accident or maybe you're tea staining paper and want to dry it quickly. Can you microwave sheets of paper or will they catch on fire?
You can microwave sheets of paper and as long as they are lying flat they are unlikely to catch on fire. Monitor the paper closely while in the microwave and don't put it in for longer than 2 minutes at a time.
If you need to microwave your paper for longer than 2 minutes then multiple shorter bursts of 30-60 seconds allowing time for the paper to cool down in between reduces the chances of fire. For smaller pieces of paper even shorter spurts in the microwave is probably better.
This quora post also has some helpful tips. Like these comments from Em:
The key thing is to watch it, and to go slow! I dry the paper in short short spurts. If it's small pieces, like a few small jar labels, I will do the first time at 10 seconds. Then 5 seconds, then 4 til its almost completely dry. I do not leave, tho, and stand right in front of microwave. I use a glass plate, too.
Can You Set Paper on Fire In The Microwave?
Is it actually possible to set paper on fire in the microwave and how does this happen?
Through my own experiments with paper, paper towels and cardboard I have discovered it's very possible to set paper on fire in the microwave.
Scrunched up paper is more likely to set on fire in the microwave than flat paper. The compacted sections build up more heat, enough to set the entire piece of paper on fire.
My partner's sister (who is only 13) put her leftover McDonalds chips in a McDonald's bag straight in the microwave and put the microwave on for 4 minutes. THE ENTIRE BAG SET ON FIRE!
It was likely the top of the bag was scrunched up and 4 minutes is definitely long enough to set paper on fire.
In my own experiments I scrunched up a brown paper bag and put it in the microwave. It only took 1 minute for the paper to start smoking and at the 2 minute mark the entire thing burst into flames.
So yes it is 100% possible to set paper on fire in the microwave.
Can You Microwave Paper Towels?
A lot of people use paper towels on top of their food to stop it splattering, or to keep it from drying out. Or some people use paper towels underneath food instead of using a plate. But can you microwave paper towels? Is it safe?
You can safely microwave paper towels on top or underneath food as long as the paper towel is flat and not scrunched up. However, paper towels may contain toxic dioxins (from the bleaching process) and these are likely to cause cancer, so avoid using paper towels in the microwave wherever possible.
I was also able to set paper towels on fire in the microwave and ran a bunch of experiments specifically on paper towels. Click here to learn if you can microwave paper towels.
Are There Health Risks Microwaving Paper?
Sure you might be worried about microwaving plastic and how that might leach chemicals into your food, but what about paper?
Surely there isn't anything bad in paper that could harm us or increase our chances of getting cancer right?
Paper is made from wood and it goes through a bleaching process in order to get to the stark white color we are used to paper being.
It has recently been discovered that this bleaching process creates a range of toxic chemicals known as dioxins.
Toxic Dioxins In Paper Products
According to the World Health Organization (WHO) dioxins are highly toxic and can cause reproductive and developmental problems, damage the immune system, interfere with hormones and also cause cancer.
This study tested for dioxins in pulp and paper mills in India and DETECTED DIOXINS IN FINISHED PAPER PRODUCTS.
This article also states that:
A series of studies by the EPA and paper industry revealed over the past five years that dioxins are a byproduct of the paper bleaching process and that some amounts of dioxins are transferred to paper products.
This means that your sheets of paper that you are microwaving could contain toxic dioxins that are harmful to you.
Formaldehyde is also commonly used in the production of paper products and can be found in paper. It is classified by the EPA as a “probable human carcinogen” which means it is likely that it causes cancer.
I couldn't find any research about leaching of dioxins into food or drink from paper only this medical research that focused on leaching of some chemicals from styrofoam products, but also included paper cups. However, this didn't focus on dioxins or formaldehyde but other harmful chemicals like styrene and benzene.
So unfortunately it seems that even the paper we use could be increasing our chances of getting cancer.
For this reason I wouldn't personally recommend heating up food and drink on paper.