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Gases and Liquids

Thread Status: Hello , There was no answer in this thread for more than 60 days.
It can take a long time to get an up-to-date response or contact with relevant users.


Deeper Blue Hypoxyphiliac
Oct 24, 2002
Hey guys, you'll have to forgive my naivite here, I haven't done any tech diving yet, but I'm a big fan and hoping too soon. I had a few questions though I thought you guys may be able to answer... :)

Firstly, I know you shouldn't listen to Hollywood, but in the Abyss where he breathes that fluid... is that possible? If so, what is it?

Secondly... from my meager understanding of DCS, what happens is breathing air with a higher partial pressure of nitrogen than is absorbed in your tissues will cause the tissues to change their nitrogen content... so if you had a controlled rebreather that kept PO2 at 0.21, partial pressure of nitrogen at 0.79 and then the remaining PP, depending on depth, with something inert like neon, then you wouldn't need to decompress at all? Does this make sense?

Thanks for your help!!
Hey Loopy shouldn't you be back on the freedive section. Man I pop over here to check out the site and half the freedive crowd's over here;) Anyway, maybe this will help w/ your questions.
First, I think the liquid thats beeen experimented w/ is a flourocarbon of some type. There's a few problems associated w/ breathing liquid though. The liquid washes away the surfactant that lines your lungs to keep the alveoli from sticking together. Then theres the mechanics of breathing a medium thats about 600x denser than air, we just weren't made to. Then there's the gas transfer from that liquid to the lungs, it would have to be supersaturated to be effective. Then when you switch back to air, while you wait for your lungs to produce surfactant you're probably on a breathing machine and most likely will develope pneumonia and die. And then probably the hardest part of liquid breathing....the first breath, I'm guessing it would be like trying to force yourself to drown. It would probably have to be done under anasthesia to prevent langarospasms(sp?).
Then the question of rebreathers eliminating deco. Rebreaters can help reduce deco by maintaining a constant PPO2/PPN2. At deeper depths N2 would probably be replaced w/ H2. Deco will still be needed to eliminate the inert gas that was absorbed at depth. Although it may be less than an open circuit dive there will still be some. Hope this helps.
Cool, that makes heaps of sense, thanks bud! :king

Is there any inert gas that the body won't absorb? (I've heard good stories about neon?)

Does anyone actually use that flourocarbon breathing thing? It seems like an awful lot of trouble... of course I was looking at it from a freediving perspective, ie fill you lungs with liquid and they won't compress... maybe even your sinus too so you don't need to eq?

Cheers for your help!
I don't know of any gas that won't be absorbed by the body. The main factors are the diffusion rate and narcotic effect. I think most of the noble gases have been tried and they work to some extent to replace N2 but w/ varing success. Hyrogen for example(can you say Hendinburg(sp?)).
As far as flooding the sinuses, you can probably talk to Eric F. about that stuff. If I flood my sinuses it's by laughing at Anderson U/W, not on purpose.;)
Hahaha :D

Hey Eric, do you read this section? Is that something you'd be able to comment on? (ie freediving with liquid in your lungs)

By the way Jay, what was supposed to be the big benefit of that? Not getting DCS or something? (ie no gas exchange)
Breathing Liquids

Hey Loopy,

About 5 or 6 years ago, I saw a news article that there were some experiments done with rats where they were submerged in some form of highly oxygenated liquid (don't know what it was or the chemical makeup) and after the rat quit panicing and "drowned" it was breathing under the surface. When they took it out of the fluid, it was totally exhausted from the effort to pump a fluid in and out of its lungs. The results, from what I recall, were not so hot because they (the rats) usually didn't live very long after the tests due to (as somone previously said) pneumonia-like problems as well as the reaspiration of the fluid while trying to get it out of the lungs (a lousy way of saying that they were unable to get all the fluid out of the lungs easily).

So, bottom line is that it should be theoretically possible but there are still lots of practical hurdles to overcome first.....

Hey Bret!

Cheers mate, that's pretty interesting... ah well, I knew there'd be some hurdle somewhere... :(
Loopy, I think they were going for less chance of DCS But I would think it was more to do w/ the narcotic effects of inert gases @ the extreme depths this was being developed for. Years ago there was also some research being done on a gill that could be implanted on a human. Haven't heard much about it lately though.
Jacque Mayol has a whole chapter on this in his

I have read that they have tried this on rats, dogs and even humans- only one lung at a time from the books that I've seen.

In the book he talks about dogs breathing this stuff underwater. He then goes on to site that most of them DIED a few hours afterwards because of the extreme workload that it placed on the lungs.


The stuff that you guys are talking about is a class of chemicals called perflourocarbons. Although early experiments with PFCs generally resulted in death of the subject, the chemicals have been refined considerably and are currently used in humans for certain applications (e.g. premature infants, burn victims with severe lung damage etc.). Can recreational use be far behind?

Here one interesting link on PFCs (typing the word "perflourocarbons" in Google will turn up hundreds more):

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