Why is Argon not used?

[vancdiver]

We all know that argon is a better insulater of gases, and Helium is not very useful at keeping our heat in.

Why don't we make a tri-mix involving argon? Or would the diffusive capabilities of this large molecule hinder it from coming out of our body quickly enough and we would have to spend more time decompressing?

 

[boomx5]

Because it's very narcotic.

 

[Don Burke]

vancdiver once bubbled... We all know that argon is a better insulater of gases, and Helium is not very useful at keeping our heat in.

Why don't we make a tri-mix involving argon? Or would the diffusive capabilities of this large molecule hinder it from coming out of our body quickly enough and we would have to spend more time decompressing?

As stated, argon is pretty narcotic, about three times as much as nitrogen as I recall. That means an ArgOx21 at 50 feet would have an equivalent narcotic depth of over 100 feet.

On that 50 foot dive, ArgOx would give longer no-stop times than air or EAN36, but the no-stop time for EAN36 at 50 feet is 220 minutes. Three hours and 40 minutes underwater is quite a while, especially when you consider that you can take a 1 hour surface interval and have 165 minutes for a limit on the second dive.

If you go beyond the no-stop time, ArgOx would require more decompression time than air or EAN36.

Perhaps there is a niche it fits into. It would have to be a pretty small niche and a trimix using argon would be even less useful. I doubt the thermal performance would be worth it.

 

[Charlie99]

This article compares and discusses various gases.
As others have noted, Argon is highly narcotic, so it isn't commonly used. Neon is less narcotic and has been used by some.

High molecular weight inert gases (Neon for example) work well for short dives where the slow absorption of the gas lengthens NDLs, but it is worse for long dives because it then takes longer to offgas.

This is similar to the situation with the relative desireability of N2 vs He for NDL dives vs deep, long deco dives.

Charlie

 

[Dr Deco]

Dear SCUBA SOURCE Readers:

Argon

What I would fear most about argon as a diving gas is its fat solubility. In laboratory studies with animals, it is possible to see a progression of problems with decompression when gases of differing solubilities are administered.

With rats, if you use helium, the rats will get limb problems and recover. With Nitrogen, they will get limb problems and then die from an overabundance of bubbles in the venous system (coming from adipose [fat] tissue.) With argon, they do not show limb problems but simply gasp for breath (too many venous bubbles) and die. Argon is a good rat poison.

Dr Deco :doctor:

 

[boomx5]

Dr Deco once bubbled...
Dear SCUBA SOURCE Readers:
Argon is a good rat poison.

Dr Deco :doctor:

if we could only figure out how to market it, we could be rich.

 

[Don Burke]

boomx5 once bubbled... if we could only figure out how to market it, we could be rich.

The only market would be people who owned recompression chambers, so it would definitely be the long way around to your first million.

 

[boomx5]

What if we marketed little tiny ones; like miniature gas chambers?

 

[Karl_in_Calif]

Charlie99 once bubbled...
This article compares and discusses various gases.
As others have noted, Argon is highly narcotic, so it isn't commonly used. Neon is less narcotic and has been used by some.

High molecular weight inert gases (Neon for example) work well for short dives where the slow absorption of the gas lengthens NDLs, but it is worse for long dives because it then takes longer to offgas.

This is similar to the situation with the relative desireability of N2 vs He for NDL dives vs deep, long deco dives.

Charlie

Charlie's URL gives the narcotic values you are taught about these gasses in a basic trimix course:

Helium 0.23 (least narcotic)
Neon 0.28
Hydrogen 0.55
Nitrogen 1.0 (the benchmark)
Argon 2.33
Krypton 7.14
Xenon 25.64 (most narcotic)

In addition to the extreme narcosis levels of argon, it is a highly dense gas. Once it got into your lungs, it would be hard to expire it again. You would probably die.

That is why argon bottles are marked with all sorts of warning labels. Not a good idea to breathe it.

 

[radagalf]

well Karl, the reason that Argon bottles are labeled is because THEY CONTAIN NO OXYGEN. This in itself, if you can believe it, is a serious problem.