3 ms·

CO2 is toxic at high concentrations though.

• akvadrako 4y ago
  It's something to be careful of, but doing it for a short time is probably fine. When sitting around, people exhale 4-5% CO₂. That's 40000 - 50000 ppm. But the Navy has done studies at that level and found it doesn't have a noticeable effect¹. > Thus, CO₂ at 40,000 ppm for 2 weeks did not affect performance on multiple tests of cognitive function in physically fit young airmen, a population probably not unlike submariners. [1]: https://nap.nationalacademies.org/read/11170/chapter/5#54 https://nap.nationalacademies.org/read/11170/chapter/5#54