I’ve heard a lot of anti-maskers use the argument that since we breathe out CO2, it will become trapped in the mask and is dangerous to breathe back in.
Obviously, this isn’t the case, because doctors wear their masks for hours and hours on end while doing surgeries. However, I am wondering, how does it work?
In: Biology
The misconception exists because you exhale about 5% CO2, and that also happens to be the concentration at which CO2 starts showing toxic effects (around 5% and higher).
And this would indeed be very deadly, if you were to breathe into a plastic bag that is tied around your head.
However, that is not what you are doing. You are breathing out into a mask, which is not airtight. Even medical masks, which are layers of melted polymers and fabric, are not air tight. If they were, yes, you would die. But they aren’t. So you never breathe in that 5% CO2 concentration you breathe out.
Make no mistake – breathing with a mask could become strenuous and eventually dangerous if you require a higher air circulation, such as when performing exerting physical activity like exercising, either for a prolonged duration of time or to a high degree of exertion, as they do restrict your air circulation to a degree (at least if the mask is any good. A simpler mask like a basic dust mask will not have as strong an effect as a medical mask, and will not be as helpful against viruses either).
But when not under physical strain or any other reason that would require a higher air circulation than usual, there’s essentially no risk.
Fun fact – in small concentrations, CO2 actually serves an important role in blood vessel constriction regulation.
Latest Answers