Extremely Deep Diving: Has Anybody Ever Used a Hydrogen/Oxygen Mixture?

People who dive to extreme depths (>600 feet) have to breath a special gas mixture, because the nitogen in ordinary air becomes toxic at high pressure. usually, these divers breath a mixture of oxygen and helium-the helium is non-toxic, and prevents the divers getting the bends when they ascend. Would hydogen be a better gas than helium? Hydrogen is even lighter, and should not dissolve in the blood.
Has it ever been tried?
of course, you would have to be careful-hydrogen and oxygen (mixed) are prone to explode.


Footnote: Deep diving indeed - that is the primary use for hydrox, which has been used for a simulated dive to over 700 metres. And in the course of finding this out, I’ve made the surprising discovery that argon can have narcotic properties - I’d never have expected that from a chemically inert element. Some geezer called Hari Seldon was asking about it.

If you put hydrogen and oxygen under that much pressure together, could they form water? You wouldn’t want that in your lungs.

Hydrogen is a highly reactive species which is both caustic (forms acids) and combustible, especially in the presence of pure oxygen. Aside from the biological hazards, there is also the issue that any equipment that provides hydrogen service has to be non-flammable, protected against hydrogen intrusion, and regularly inspected for corrosion and embrittlement. On the other hand, helium, being chemically non-reactive in any terrestrial conditions, can be stored in a standard pressure tank with no concerns about corrosion or reactivity, and is biologically completely inert.


Its been done.

And its my understanding that it does have some advantages over helium for really deep dives but I don’t think its been used much for other than research purposes.

As for the hydrogen/oxygen blowing up thing, you have to remember for really deep dives only a tiny fraction is oxygen and it becomes impossible for a flame to maintain itself in such an atmosphere, much less an explosion.

The bigger problems would be making the mix in the first place, and the transition from the deep to the shallow would be more complicated because at some point the oxygen percentage has to be high enough that you can’t have much hydrogen around. Maybe decoing divers could do some cool breathing fire tricks as they outgassed hydrogen from their lungs.

I think hydrogen gets an overly bad rap. We handle plenty of other dangerous and unforgiving gases, compounds, and materials quite safely when approached properly.

One interesting thing about hydrogen is that it CAN be reactive, unlike helium. It might be possible someday to inject a compound into a human that reacts with the hydrogen so that the body can be degassed faster or safer.

And yeah, the noble gasses ARE “narcotic” and IIRC the heavier the gas, the moreso it is.

Oh, and massive quantities of helium can get fairly pricey. Hydrogen is pretty cheap.

Deep cave divers can blow hundreds of dollars each on a big dive for helium costs. If that group gets a little better at diving a bit deeper than is common for them now, it wouldnt surprise me to see them trying to work some hydrogen into the mix. Some of those guys will try anything that doesnt appear downright suicidal.

Uh, cite? AFAIK, Hydrogen is NOT highly reactive under standard conditions, not that combustible under diving conditions, does not spontaneously form acids, and is not biologically active. Furthermore, breathing helium/oxygen blends cause high pressure nervous syndrome, which hydrogen/oxygen does not.

ETA: this is a reply to Stranger on a Train’s post.

Quite. Not your finest hour, Stranger. :dubious:

Nope, they’d still need to burn, and the idea is to discourage this as strongly as possible - they won’t spontaneously stick together.

One popular alternative I really like is dipping them in milk when Oreos are not available. Chips Ahoy are a possibility in this situation but are significantly different than Hydrox.

Aren’t they getting hard to find again, though?