Can Wearing Masks for Long Lead to Hypercapnia or High CO2?

The claim about wearing a face mask for an extended period of time could cause hypercapnia, a condition caused by a build-up of carbon dioxide (CO2) in the blood or excessive carbon dioxide levels in the blood due to “rebreathing your own CO2” could be poisonous was circulated on various social media platforms like Facebook, Twitter and Instagram, accompanied by images. The claim did not specify which types of face masks it refers to.

What is hypercapnia?

Hypercapnia (also known as hypercarbia, hypercapnea), or carbon dioxide toxicity can result in an altered mental state, loss of consciousness, an irregular heartbeat, breathing difficulties, and can even be fatal. But very few people are at risk of experiencing hypercapnia in their everyday lives while wearing masks, face coverings, or not.

Even if you wear a mask, the chances are not likely to be possible as carbon dioxide molecules are simply too small to be controlled by the majority of mask materials and simply pass right through. 

How can coronavirus particles be restricted then?

Face masks help to restrict contact with infectious droplets that carry pathogens. However, the material used for face masks are still porous enough to allow gas molecules, like carbon dioxide and oxygen, to pass through, and do not significantly impair gas exchange to the point of causing hypercapnia or let it accumulate. 

Coronavirus particles have been measured and their size is approximately 125 nanometers, ranging from 60 to 140nm. They are so small that they can’t be seen under regular microscopes and need specialized ones unlike most bacteria and fungi which can often be seen with light microscopes.

But carbon dioxide, oxygen and other gaseous molecules in the air like nitrogen, are much, much smaller than the coronavirus and will pass right through both the filter and main material of even an N95 mask and from pretty much any other home-made or mass-manufactured mask materials as well.

After appearing on multiple social media platforms about masks and carbon dioxide toxicity, there was a dilemma amongst people as it says masks could trap exhaled carbon dioxide and cause us to breathe it back in. It explains that this process could lead to CO2 intoxication or poisoning which, in turn, can cause breathing problems, muscle twitches, loss of consciousness and more.

While high concentrations of carbon dioxide can affect your health, we can say that the claims about masks causing carbon dioxide poisoning or toxicity are false.

The Center for Disease Control and Prevention (CDC) says it’s unlikely in medical masks and even less likely in homemade masks. They said carbon dioxide can build up over time in masks, but not to a dangerous level. There are chances that you may get a headache, but not carbon dioxide poisoning.

Based on research about medical quality equipment like N95 masks, they have a tighter seal and allow less air passage. Though it is advised that you shouldn’t be wearing these for long periods anyway. The CDC also recommends masks when you’re out in public or when you can’t social distance.

The hastily-cobbled together graphics and memes currently circulating on social media claim that prolonged wearing of masks can increase levels of carbon dioxide, resulting in a myriad of symptoms but cannot cause hypercapnia or toxicity to a dangerous level.

Over to you
The claim is misleading as health experts in Thailand have said that as of May 2020, there is no evidence that wearing a mask for a long period can cause hypercapnia or toxicity of CO2. On Facebook, the post was shared more than 250 times. It is clear that there’s almost no scientific evidence or research which proves that wearing facemasks can lead to carbon dioxide poisoning.

We advise you to be cautious of what you see, read, share, and apply to practicality in real on social media.