Fact or Fiction? Masking and CO2 Dangers

As the COVID-19 pandemic unfolds, experts are urging the use of protective masks.  While experts weigh in, misinformation is running rampant on social media.  So, will carbon dioxide become trapped and build in your body? Read on for the final verdict.

Updated:  

Fact or Fiction? Masking and CO2 Dangers

As the COVID-19 pandemic unfolds, health experts continue to urge the public to wear face masks for protection. Sound advice, right? Well.. if you spend any time on social media it’s likely you’ve read warnings about the dangers of wearing a mask for long periods of time. Specifically, the risk of carbon dioxide (CO2) becoming trapped under your mask, causing unsafe levels to build up in the body (hypercapnia). So, let’s take a closer look to see if wearing a mask can lead to someone passing out or worse.

A Possible Catalyst

One April incident added fuel to the “masking causing carbon dioxide poisoning” theory. On April 25, 2020, a New Jersey woman crashed her car into a power pole and was taken to a nearby hospital. The local police department posted to facebook that the woman had been wearing an N95 mask for several hours and passed out. The department believed wearing the N95 mask contributed to the crash by causing a buildup of carbon dioxide and resulting in the driver fainting.

The facebook post was shared thousands of times and received hundreds of comments. The story was also reported on major news outlets.

The Basics

Let’s first review the characteristics of protective masks as we look for the truth. There are two main types of masks used in healthcare, N95 respirators and surgical masks.

Surgical

These masks are fluid resistant, fit loosely and protect you from large droplets, splashes or sprays of body or hazardous fluids. They also protect others from your own respiratory and body secretions. However, there are limits to protection surgical masks provide, including:

  • Does not provide reliable protection from small airborne particles
  • Are not considered respiratory protection
  • Leakage occurs around the edge of the mask when you inhale
  • Designed for single use

N95 Respirators

The N95 respirator is tight-fitting and requires a fit test to make you have a good seal around the mask. It protects you against small particle aerosols and large droplets. In fact, it filters out at least 95% of small and large airborne particles. If properly fitted, minimal leakage occurs around the edges when you inhale. N95 masks also have limitations, including:

  • Ideally, N95 masks should be discarded after each patient encounter
  • Is ineffective if a good seal is not maintained
  • Breathing can become difficult

The Verdict

A CDC representative told Reuters that CO2 will build up in face masks over time, however, the level of CO2 trapped is tolerable for most of us. Protective masks are designed to trap droplets, which are much larger than CO2 particles. Therefore, CO2 will escape through or around the edges of surgical, cloth and even N95 masks. If CO2 levels do rise high enough to cause symptoms, we would most likely remove the mask.

Healthcare workers, who wear masks for extended periods of time, could potentially experience symptoms of elevated CO2 levels (I.e. headaches and dizziness).

Caveat: Preexisting Conditions

People with respiratory conditions (such as COPD) that cause hypercapnia may experience breathing difficulties. Therefore, the CDC does not recommend face masks for anyone having breathing difficulties or other conditions that will increase the risk of hypercapnia.

Have you experienced any other “myths” or “truths” related to masking during the pandemic?

References

Driver in crash may have passed out from wearing N95 mask too long: Police

Killer COVID-19 Masks? The Truth About Trapped Carbon Dioxide

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J.Adderton

About J.Adderton, BSN, MSN

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J. Adderton MSN has over 20 years experience in clinical leadership, staff development, project management and nursing education. 

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"People with asthma can't wear masks". Uh noooo, people in the middle of an attack can't but otherwise we're good to go. ?

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It's a really interesting topic. I wish there was more actual peer-reviewed evidence instead of a bunch of supposition (not a criticism of the article, but a criticism of the situation as a whole).

On 7/1/2020 at 8:40 AM, J.Adderton said:
Therefore, CO2 will escape through or around the edges of surgical, cloth and even N95 masks. If CO2 levels do rise high enough to cause symptoms, we would most likely remove the mask.

Healthcare workers, who wear masks for extended periods of time, could potentially experience symptoms of elevated CO2 levels (I.e. headaches and dizziness).

I don't dispute the surgical mask concept one bit--surgeons have been doing literal brain and heart surgery for decades while wearing surgical masks for several hours at a time, and it hasn't impaired their psychomotor abilities.

However, I have far more concerns about the consequences of N95s. Even though CO2 can diffuse through the N95 mask, I'd imagine that it 'escapes' at a far slower rate than with a surgical mask. That would allow the CO2 to accumulate to much more quickly at higher levels, and would slow CO2 diffusion in the lungs.

An ICU friend of mine told me that she and her friends tested their O2 sats both before and wearing masks, and they were the equal. However, even if their oxygenation is fine, I still worry about ventilation being impaired due to CO2 rebreathing. It's entirely possible for people to be well oxygenated and poorly ventilated, and it would be really interesting to check capillary gases on nurses before and after long stretches in N95s.

The article states that once people become symptomatic, they can just take off their masks, and the symptoms will self-resolve. Unfortunately, unlike laypeople, most nurses don't have the luxury of just 'taking off the mask' whenever they don't feel well. Even if nurses get headaches because their N95s make them hypercapnic, they can't always ignore patient needs because they want a mask break.

I really want to see concrete data about the functionality of reusing masks that were designed (and tested/approved) for single-use. It's hard to know how many uses you can get out of mask (surgical or N95) before they become less effective, since that's never been an issue in the past. In circumstances were masks are reused for weeks on end, I wonder if they actually provide much protection at all. I also wonder if after a certain amount of time, they become carriers of other nasty parasites; even if COVID dies on cardboard within 24 hours, the hardier bacteria/fungus from your mouth and face might still thrive on used, damp masks.

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4 hours ago, adventure_rn said:

It's a really interesting topic. I wish there was more actual peer-reviewed evidence instead of a bunch of supposition (not a criticism of the article, but a criticism of the situation as a whole).

I don't dispute the surgical mask concept one bit--surgeons have been doing literal brain and heart surgery for decades while wearing surgical masks for several hours at a time, and it hasn't impaired their psychomotor abilities.

However, I have far more concerns about the consequences of N95s. Even though CO2 can diffuse through the N95 mask, I'd imagine that it 'escapes' at a far slower rate than with a surgical mask. That would allow the CO2 to accumulate to much more quickly at higher levels, and would slow CO2 diffusion in the lungs.

An ICU friend of mine told me that she and her friends tested their O2 sats both before and wearing masks, and they were the equal. However, even if their oxygenation is fine, I still worry about ventilation being impaired due to CO2 rebreathing. It's entirely possible for people to be well oxygenated and poorly ventilated, and it would be really interesting to check capillary gases on nurses before and after long stretches in N95s.

The article states that once people become symptomatic, they can just take off their masks, and the symptoms will self-resolve. Unfortunately, unlike laypeople, most nurses don't have the luxury of just 'taking off the mask' whenever they don't feel well. Even if nurses get headaches because their N95s make them hypercapnic, they can't always ignore patient needs because they want a mask break.

I really want to see concrete data about the functionality of reusing masks that were designed (and tested/approved) for single-use. It's hard to know how many uses you can get out of mask (surgical or N95) before they become less effective, since that's never been an issue in the past. In circumstances were masks are reused for weeks on end, I wonder if they actually provide much protection at all. I also wonder if after a certain amount of time, they become carriers of other nasty parasites; even if COVID dies on cardboard within 24 hours, the hardier bacteria/fungus from your mouth and face might still thrive on used, damp masks.

I saw a nurse on Instagram that did capnography with 3 masks on with minimal impact. It was an interesting video.

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5 hours ago, Wuzzie said:

"People with asthma can't wear masks". Uh noooo, people in the middle of an attack can't but otherwise we're good to go. ?

Sounds like that lady on the video making rounds on social media having the full meltdown claiming she has breathing problems and her doctor told her not to wear a mask and if they try to make her wear one it's violating federal law. I never laughed so hard! She was irate and dead serious. It's a mess. ?

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3 minutes ago, NurseBlaq said:

Sounds like that lady on the video making rounds on social media having the full meltdown claiming she has breathing problems and her doctor told her not to wear a mask and if they try to make her wear one it's violating federal law. I never laughed so hard! She was irate and dead serious. It's a mess. ?

Was she the one quoting scripture about God breathing life into Adam?

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9 minutes ago, Wuzzie said:

Was she the one quoting scripture about God breathing life into Adam?

No that was a different one!

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12 minutes ago, NurseBlaq said:

No that was a different one!

Yikes!

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Specializes in ED, psych.
1 hour ago, NurseBlaq said:

Sounds like that lady on the video making rounds on social media having the full meltdown claiming she has breathing problems and her doctor told her not to wear a mask and if they try to make her wear one it's violating federal law. I never laughed so hard! She was irate and dead serious. It's a mess. ?

Was she the one ranting and raving at Trader Joe’s? For the duration she was screaming, if she wore the dang mask, she would’ve been in and out of there. Plus, her lungs sure did give her no issue while she was yelling.

These people give me a headache. More than any mask.

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2 minutes ago, pixierose said:

Was she the one ranting and raving at Trader Joe’s? For the duration she was screaming, if she wore the dang mask, she would’ve been in and out of there. Plus, her lungs sure did give her no issue while she was yelling.

These people give me a headache. More than any mask.

That's her!

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I'm really sick of these covid denying idiots saying "I have a medical condition" as their excuse to not wear a cloth/surgical mask out in public...and sick of all of the businesses that blatantly TELL them they don't have to wear a mask if they say they have a "medical condition."

Since when has a "medical condition" prevented any of us RNs from working??!! It's not. I don't get to go to work and pull this b.s. and they shouldn't be allowed to, either.

It's all so depressing how little people care about their fellow man.

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Out of curiosity, would there be a CO2 risk if wearing a mask while working out? I know some gyms require them, that would be the only time I would really worry about it

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