My understanding is that like many things, both low and high are bad (high carbon dioxide is called hypercapnia), so you want to be in the “good” range (I typically see 35-45 mmHg of partial pressure carbon dioxide being cited as the good range). In rationalist circles I have seen discussion of too-high atmospheric carbon dioxide being bad, but I am myself confused on how that connects to carbon dioxide levels in the blood (and separately, I’m not convinced that higher carbon dioxide levels in the air are bad either).
I typically see 35-45 mmHg of partial pressure carbon dioxide being cited as the good range
That’s about 5% (since atmospheric pressure is about 760 mmHg) or 50,000 ppm.
Being in a room with that high a concentration of co2 is immediately dangerous
to life and health, which is a good illustration of the fact that this post (your post) is about co2 in exhaled air, which
is distinct from co2 in inhaled air or ambient air, where for example
5,000 ppm of co2 “is the permissible exposure limit for daily workplace exposures” (source).
Too much is bad, too little is bad, it has a number of important functions, so that poisonous bit is a huge oversimplification that gets repeated a lot, but is clearly incorrect if you need some to be alive.
low carbon dioxide levels being bad is surprising to me. isn’t carbon dioxide poisonous?
My understanding is that like many things, both low and high are bad (high carbon dioxide is called hypercapnia), so you want to be in the “good” range (I typically see 35-45 mmHg of partial pressure carbon dioxide being cited as the good range). In rationalist circles I have seen discussion of too-high atmospheric carbon dioxide being bad, but I am myself confused on how that connects to carbon dioxide levels in the blood (and separately, I’m not convinced that higher carbon dioxide levels in the air are bad either).
That’s about 5% (since atmospheric pressure is about 760 mmHg) or 50,000 ppm. Being in a room with that high a concentration of co2 is immediately dangerous to life and health, which is a good illustration of the fact that this post (your post) is about co2 in exhaled air, which is distinct from co2 in inhaled air or ambient air, where for example 5,000 ppm of co2 “is the permissible exposure limit for daily workplace exposures” (source).
Too much is bad, too little is bad, it has a number of important functions, so that poisonous bit is a huge oversimplification that gets repeated a lot, but is clearly incorrect if you need some to be alive.