How is it not dangerous to breathe in the CO2 that we breathe out into our masks?

Question

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

Answer 1

CO2 does not cause damage to any tissues, the only danger is it getting in the way of the O2 you need in your lungs and ultimately your brain. If you legitimately start passing out, go ahead and pull your mask down for a minute, but like everyone else is saying, those molecules won’t get stuck in any sensible mask.