In article
,
Ian H writes:
Its 2094000 ppm of oxygen

One too many zeroes there!

versus around 360 ppm of carbon dioxide at
the last count! For us humans as long as the oxygen value stays above
about 180000 ppm, we should not have any breathing difficulties (at
sea level). However, a carbon dioxide level of greater than 5000 ppm
would exceed current safe exposure limits for breathing in this gas.
Mind you if it reached that level, we'd all be doomed well before that!

Indeed.
--
John Hall
"Acting is merely the art of keeping a large group of people
from coughing."
Sir Ralph Richardson (1902-83)