Argon/air as a bailout mixture?

[mattiedread]

Ar is not something you would voluntarily put in your lungs. More often than not it is fatal. It is heavier than air (air floats on it).

There are manufacturing processes that take place in Argon pits (absence of air). The general rule of thumb is that these can't be insured in the US (3rd world) and they are dangerous as hell to work around because of the low probability of survival if something goes wrong. I don't remember all the specifics, but if you got a lung full Ar, you basically had little chance of survival.

Now, these pits use 99+% pure Ar, not a mixture. But, I think I recall serious safty warnings that once Ar is in your lungs your respitory system is seriously compromised.

 

[detroit diver]

Spectre once bubbled...
I decided the best way to confirm or deny a rumor is to go straight to the source. I received a response back this evening.

Dr. Hamilton states "I have never said anything like this".

So for the record, the rumor is untrue.

Thank you.

 

[Spectre]

mattiedread once bubbled...
Ar is not something you would voluntarily put in your lungs. More often than not it is fatal.

Is this true? I was reading an article in Advanced Diver that touched on 5 inert gasses [Hydrogen, Helium, Neon, Nitrogen and Argon] showing the pros and cons and how Helium was chosen as the best inert gas to use.

Is it that Argon is fatal, or is a hypoxic issue from the lack of oxygen present in the example you refer to?

 

[Cave Diver]

detroit diver once bubbled...
Can anyone confirm a rumor that a 50/50 mix of Argon and air is being touted as a bailout mix by Bill Hamilton? I've seen a couple of emails that this is a new procudure that is recommended, and would like to know if anyone can confirm this.

Thanks,

Jack

I heard something similar regarding air (or oxygen) being added to argon to make it breathable in the event of an emergency.

Out of curiosity I posed the question to someone with more knowledge of it than me.

The response I got was that an argon bottle would only have a drysyuit inflation hose on it, not a second stage, so how would you breathe it in the first place? (Doh! Why didnt I think of that?)

And even if you WERE able to put a regulator on it, how big is an Argon bottle anyway??? If you're that concerned about bailout, you may as well carry a spare air <ducking>.

 

[mattiedread]

I'm not very knowledgable in matters of physiology but here are a few things I dug up from doing a Dogpile search for "Argon and Safety":

It is classified as a 'SA' by ANSI, which is simple asphyxiant. Again I'm no physiologist so the dangers of controlled inhaling are out of my knowledge scope.

It is 1.38x denser than air, so it sinks (coupled with being inert is why it is used as an atmosphere in reactionary processes). Again unqualified, it seems to me it would be 'last out' of your lungs even at 2ATMs and could conceivably build up in your lungs preventing enough oxegen from entering your blood. This is the exact danger I recall being lectured about... In addition, because it is denser your body has difficulty expelling it.

Here is a site (.pdf) that has rather forbodding warnings about inhaling it: (although they assume a release into a normal atmosphere with 19% O2, I think):
http://www.praxair.com/praxair.nsf/0/d03e8b4aa7b2958785256a86008095f7/$FILE/p4563g.pdf

The .pdf is worth a quick look to get an overview of the hazards associated with welding with it (the standard is for the Ar concentration to be less than 5mg/cubic meter of air, which doesn't seem like all that much).

In addition there seems to be a cookie cutter safety sheet that welding supply stores post on using argon that insist on proper ventilation and SCUBA type safety aperatuses are required for rescue workers.

It is also used as a fire suppression agent. It is effective because it quickly displaces the O down to levels that don't support combustion (like a Halon system).

My previous post came from the recollection of horror stories from a manufacturing process, and actual data on fatalities at a plant in South America (or Saudi Arabia, it was either TiO2 or SiO2 being stripped of O) and how very little could be done once someone got a lung full of PURE Ar. (Again, the implications of 50/50 are beyond me).

So, even if a few bubbles on the brain doesn't bother (Docs post), the risk of hypoxia/ashyxiation makes lighter inert gases more appealing, IMHO.

I'd be interested in any more info anyone could dig up.