As I understand it, 100% oxygen at sea level pressure is fatal. There can be too much of a good thing. Deep diving gas mixtures are nearly entirely helium, because the oxygen fraction has to be within the safety limit for the depth pressure of operation.
As I understand it, 100% oxygen at sea level pressure is fatal. There can be too much of a good thing. Deep diving gas mixtures are nearly entirely helium, because the oxygen fraction has to be within the safety limit for the depth pressure of operation.