Is Wearing a Mask Dangerous?

Size Matters

The claim that a mask will cause a build-up of carbon dioxide, or CO2, behind your mask while breathing in and out while wearing it is false. Alarmists that feel that wearing a mask is somehow infringing on their rights (just like wearing a seatbelt or stopping at stop signs are both the height of tyranny, /s), or believe that they could die by wearing such restrictive masks are wrong. This is not true, and the size of things is the proof. Let’s break down some simple science.

The claim is easy enough to debunk—notwithstanding the fact that thousands of surgeons wear one every day for multiple hours while conducting complex, arduous and life-saving procedures. Oxygen, the life-giving gas we breath in, and carbon dioxide, the waste gas that we exhale, are very, made up of very small molecules. The sizes of a molecule of oxygen or carbon dioxide are approximately 152 pm and 116 pm, respectively. What’s a pm? It’s picometer, which is one millionth of a micron (also known as a micrometer). A human hair is about 150 microns wide, so yes, a molecule of gas is extremely small, even compared to a virus, which range from 0.06 to 0.14 microns.

“[Masks do] not impede oxygen flow and [do] not increase your carbon dioxide levels. Not at all,” says Jamie Rutland, M.D., a pulmonary and critical care physician who’s a national spokesperson for the American Lung Association and an assistant clinical professor of internal medicine at the University of California, Riverside School of Medicine. The bottom line is oxygen and carbon dioxide are such small molecules, they can easily fit through the pores of the mask, which means CO2 levels won’t increase in the space under the mask and harm or kill you.

The textile that makes up an N95 mask, the ones that are recommended for use by medical professionals when around people infected with Covid-19, which is around 0.12 microns in diameter, have to meet tolerances that block 95 percent of particles with a diameter of 0.3 microns. Hmm, you’re probably saying at this point… the virus is 0.12 microns, which is smaller than 0.3! Gotcha, the virus can easily slip through, so there’s no reason to even wear them and make me uncomfortable and stuffy and my skin around my mouth slightly overheated!

You’d be right if a solitary virus was placed on the mask in a lab setting, but in the real world, viruses don’t go flying around own their own, hopping from person to person. They don’t have wings or any way to move around by themselves, which is why coughing and sneezing is the main way they spread from person to person. The virus must be attached to something like a water droplet to even make it to your face, says Rutland. “It’s not like a virus is traveling in the air by itself, it’s usually surrounded by some kind of material that’s a certain size,” he says.

These liquid particles, droplets and smaller aerosols, are, at their smallest, about 1 micron in size. This is why N95 masks, and other cloth masks, are effective at slowing the spread of Covid-19, whether you are inhaling or exhaling, because any viruses must be bonded to water to make it anywhere near our faces.

Respiration Refresher

If that makes sense to you, and the science is acceptable, you may be led to another question. What if the carbon dioxide (or oxygen) was also able to attach itself to water droplets as you exhale? Then would the whole mass of water and gas would be too big to travel through the mask, making you susceptible to being overwhelmed by CO2? Sorry, but according to the laws of chemistry and physics, it’s not possible, says Paul W. Davenport, Ph.D., a distinguished professor in the department of physiological sciences at the University of Florida.

“Masks are very effective in stopping air droplets that can contain the virus,” he says. “[But the] O2 and CO2 molecules are not bonded to the water droplets and O2 and CO2 are not stopped by the masks—they are free molecules in the inhaled and exhaled air.” This separation of a gas and liquid relates to the Ideal Gas Law, the Law of Partial Pressures, Dalton’s law and Henry’s law, which are complex gas laws that help us understand how gases and liquids will and won’t mix depending on certain densities and pressures. “This [Henry’s Law] is very important for blood transporting O2 from the lung to the tissues,” says Davenport, “but does not apply for the amount of O2 or CO2 in the gas phase, or air the person is breathing.”

As you exhale gases and water vapor into the surrounding air, they are come out separate since the atmospheric pressure is equalized, like the spray of CO2 and liquid that emits after opening a fizzy beverage. When you open a soda or seltzer—that eruption of spray is just carbon dioxide being released from the liquid inside the pressurized can or bottle. The liquid in the container, before being opened, is under similar pressures to the blood that courses through our veins, which is why the gases stay in the blood (liquid). Our blood must transport the oxygen and carbon dioxide as it helps complete our respiratory cycle, which is the process of getting the oxygen (and other gases) you breathe into and out of the heart and lungs and to the rest of the cells, tissues, and organs.

Why Are Masks Annoying?

At this point, perhaps the science has you mostly convinced that you’re not going to die from CO2 poisoning while wearing an approved mask. But, you just don’t like to wear the darn things — they’re uncomfortable, hot and annoying. That’s true, says Davenport, but it doesn’t matter if you’re interested in stopping the spread of the virus.

“Fundamentally, if the [mask] material is easy to breathe through, then it is not filtering the air.” This difficulty in breathing is creates an aversive reaction that makes people want to rip off their mask. “Removing the mask, especially when exercising, increases the distance the exhaled air can travel and increases the chance for spread of the virus,” he says. “In addition, increased inhalation breathing effort during exercise without a face mask will bring contaminated air into your respiratory system from a further distance away.”

The only reason to not wear a mask is related to psychological issues, not any chronic lung disease, says Rutland. “If you have issues with anxiety, if you have issues with hypersensitivity to your skin, you can have reasons not to wear a mask, but typically speaking, there really is no reason for someone not to wear a mask.”

Gas In, Gas Out—No Pass Out

Though true that viruses are small enough, on their own, to slip through the gaps in the textiles that make up masks, they have to get around our environment attached to water droplets, which masks are made to specifically filter. Gases, like oxygen and carbon dioxide, are extremely small—remember they are about one millionth smaller than a micron, which is what N95 masks are tasked with blocking to a 95-percent efficiency.

Physically, there is no way an N95 could cause a build-up of gases, oxygen or carbon dioxide between the barrier and your mouth and nose. Can they trap heat and moisture and make you feel uncomfortable and add resistance to your breathing? Of course, but it you aren’t going to asphyxiate or pass out or hyperventilate from rebreathing excess carbon dioxide, so mask up.