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Originally Posted by vicky_molokh
Thanks, this is exactly the sort of thing I was wondering about. Is there a way to measure the level of this fire hazard based on oxygen content? (I'm assuming you mean specifically the %, since partial pressure is no higher than normal.)
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Yes, the thing about neutral gases is that they absorb heat from a reaction and thus prevent a self-sustaining flame when one would occur in the pure gas. I don't have exact numbers, though; it's just 'more dangerous'. It also tends to mean that you have supplies of compressed or liquid pure oxygen sitting around, which is most certainly a fire hazard.
Quote:
Originally Posted by vicky_molokh
Also, what's so surprising about being able to lower CO2 to human-acceptable levels?
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Unlike nitrogen, CO2 is quite significantly soluble in water, and forms a weak acid when doing so; something adapted to a certain level of blood acidity would probably notice its absence. Humans are used to about 3 mbar of CO2, and more than about 10 mbar is unsafe long term.