Face Coverings and Carbon Dioxide Exposures

2/1/2021

Many of us spend time on social media sites engaged in various discussions on a variety of topics.  There is certainly a lot of activity out there. And while the initial intent of these sites was to be an outlet for people to share ideas and opinions on various subjects with others, we have found that the level of passion can easily get out-of-control, resulting in a loss of tolerance and even seeing accusatory remarks going beyond objectivity and into the realm of insulting and even threatening! I, myself, try to stay on focus and participate on subjects for which I have an understanding. One of those topics, obviously, is occupational safety and health.  And recently I found myself in a little tete-a-tete about whether face coverings and face masks promote carbon dioxide poisoning.

I first heard of people being concerned about getting poisoned by carbon dioxide (CO₂) by wearing masks last summer when news networks presented a number of stories of local city council meetings and community members voicing their apprehension of wearing face coverings as they believed these devices were allowing carbon dioxide (CO₂) to accumulate around the nose and mouth.  The result, based on their understanding, was that this accumulation would result in CO₂ poisoning.

CO₂ is a gas found in our atmosphere at concentrations ranging from 280 – 400 parts per million (ppm); concentrations may alter depending on the specific activities (industrial and vehicular activities) in a specific area (mainly urban versus rural).

CO₂ is classified as a simple asphyxiant. This means that a chemical reaction does NOT occur, thereby interfering with our biological systems in the transportation of oxygens on a cellular level. Rather CO₂ displaces oxygen in the atmosphere so that we would suffocate from a lack of oxygen getting into our lungs.

Make no mistake. Simple asphyxiants can cause serious health effects. One of the most illustrated examples was presented in the movie, “Apollo 13,” where, after being stranded in space, the ship’s monitoring system began to measure a build-up of CO₂. The concern was if this build-up continued, oxygen within the space vessel would be displaced, eventually causing the astronauts to succumb to hypoxia (inadequate oxygen in the body).

From an occupational perspective, organizations that are dedicated to occupational S&H, have established exposure limits for CO₂.  The American Conference of Governmental Industrial Hygienists (ACGIH) developed the 8-hour threshold limit value (TLV) for CO₂ at 5,000 ppm as well as a short-term exposure limit (STEL) of 30,000 ppm. These limits are designed to protect workers from an overexposure of CO₂ for an 8-hour work shift and for 15-minute exposure periods, respectively. OSHA has a permissible exposure limit (PEL) for CO₂ at 5000 ppm (which is the same as the ACGIH TLV).  The National Institute for Occupational Safety and Health (NIOSH) has established 40,000 ppm as the “Immediately Dangerous to Life and Health” (IDLH) exposure limit: a recently revised concentration from 50,000.  The IDLH is a concentration for which a person can remain in the immediate are for up to 30-minutes period without experiencing serious health effects. This concentration is intended to be an awareness level for which people need to leave the area immediate (and not to wait for the designated 30-minute period). NIOSH recognizes that CO₂ concentrations of 70,000 -100,000 ppm may produce unconsciousness after a few minutes of exposure.

According to the Mayo Clinic¹ and the Centers for Disease Control and Prevention (CDC)², wearing a face mask does not lead to carbon dioxide poisoning, even for people with lung disease. For many years, health care providers have worn masks for extended periods of time with no adverse health reactions. Such is the case where doctors and nurses work in the operating room for hours under intense stress while wearing surgical masks. Yet there has never been a single case reported of these workers succumbing to hypoxia.  The CDC recommends wearing cloth masks while in public, as cloth material is very breathable. There is no risk of hypoxia, in healthy adults. Carbon dioxide will freely diffuse through your mask as you breathe.

A recent study (published online Oct. 2 in the Annals of the American Thoracic Society)  has monitored changes in oxygen and carbon dioxide levels in healthy people as well as in those with chronic obstructive pulmonary disease (COPD). The study monitored test subjects before and during the use of surgical masks. In general, people with COPD must “work harder to breathe,” which can lead to shortness of breath and/or a tired feeling, according to the American Thoracic Society. The study found that the effects of wearing masks are minimal at most; even in people with very severe lung impairment.   

The study even addresses the feeling many of us get that causes a shortness of breath when we wear a mask while performing heavy work. The specific term, known as dyspnea, is not synonymous with the gas exchange process that takes place in our lower regions of the respiratory system. Rather, it is associated with the restriction of air flow with the mask when higher ventilation is needed (due to heavy physical exertion). 

For example, if you’re walking briskly up a hill, you may experience breathlessness, and a mask that is too tight may increase that feeling. The solution: Slow down or remove the mask if you’re at a safe distance from other people. But the mask will not allow CO₂ to accumulate in one’s breathing zone.

The study concludes that it is important that the public understand that the discomfort associated with wearing a mask is not an indication of CO₂ poisoning. The study simply states that, “The public should not believe that masks kill.”

I’ve learned that you shouldn’t go through life with a catcher’s mitt on both hands; you need to be able to throw something back.

Maya Angelou

1 https://www.mayoclinichealthsystem.org/hometown-health/speaking-of-health/debunked-myths-about-face-masks

2 https://www.cdc.gov/coronavirus/2019-ncov/prevent-getting-sick/cloth-face-cover-guidance.html