Narcosis Properties of Different Gases

[boulderjohn]

Did that poster have any linked research or were we to accept his word on it as well?

Cut down to size, his argument was the same--only nitrogen causes narcosis, so taking some of it away has to be better. No, he had no research to support it, either.

 

[gianaameri]

Cut down to size, his argument was the same--only nitrogen causes narcosis, so taking some of it away has to be better. No, he had no research to support it, either.

The above is not my argument, please, and I have made no argument (other than a couple of jokes and pointed out some personal observations based on my personal diving experiences), but a statement of fact.

The fact is that there is no evidence that O2 is narcotic at recreational diving depths.

If anyone has any, please provide it and it will enhance my knowledge.

 

[nimoh]

O2 is NOT narcotic at recreational diving depths.

this looks like an argument, or was it intended as a joke?

 

[dfx]

this looks like an argument, or was it intended as a joke?

He has repeated it about 20 times now, it has to be true!

 

[ScubaSteve]

He has repeated it about 20 times now, it has to be true!

We did after all read it on the internet.

 

[victorzamora]

We are very close to agreement.

For dives outside the recreational envelope, given the research to date it would be prudent to treat O2 as narcotic (i.e. for Trimix or Heliox dives)

Yup, agreed.

For a cave dive to 100', it would be imprudent to suggest the use of Air in place of N32.

Also a moot point. If available, cave divers will ALWAYS go with EANx due to the increased NDL and/or decreased deco time. Especially diving doubles to thirds, you'll incur a lot of deco at 100' on air. So, if O2 IS narcotic (approximately as narcotic as N2)...then it doesn't matter. If O2 isn't, you're better off....but you'd be diving EANx32 for NDL concerns anyway. No point in arguing there, as you either would or wouldn't get the benefit.

For a 100' dive in the Maldives no current or drifting, the argument is perfectly moot.

Again, agreed. Some people with big tanks or low SAC rates may switch to EANx for the increase in NDL. I know I hit my NDL easily at 80-130ft on air, even in an AL80...and I'm a big guy. Also, the reduction in narcosis (apparent or otherwise) has been agreed upon resolutely before this conversation, so it's much less of a concern here.

An emergency drop to 18 - 21 meter using an O2 rebreather (as taught in military circles), the argument is also perfectly moot (O2 narcosis is never an issue, and if anything is bad with O2 at those depths you convulse before you narc out).

Moot due to OxTox concerns, first and foremost. However, air isn't really considered narcotic until below 80ft (24.5m)....so the point about 60-70ft (18-21m) is moot due to the narcotic effects of air being negligible.

So, circumstances and environment are relevant.

In terms of the effects of narcosis, yes....but not on whether or not O2 is narcotic. I'm not arguing one way or the other, but physics and physiology don't know if you're in a cave or in good vis or bad vis. If O2 is narcotic, then it's always narcotic. If it's not, it's not. Impairment is a different issue, and that is HUGELY affected by conditions.

 

[gianaameri]

this looks like an argument, or was it intended as a joke?

It is a statement of fact, not an argument.

There is no evidence that O2 is narcotic at recreational depths = O2 is NOT narcotic at recreational depths.

I never stated "only nitrogen causes narcosis" - such statement is NOT true (and NOT mine) because there is evidence O2 is narcotic outside recreational depths (i.e. at 1.65 pPO2 science says there is a 10% impairment).

Please stop running around like brainless chicken and face some simple facts of life. If you can't handle that fact that no evidence exist to support the (erroneous) belief O2 is narcotic at recreational depths, stop posting, as it is not productive (or if you post do not do so to twist around my statements).

 

[dfx]

The fact is that there is no evidence that O2 is narcotic at recreational diving depths.

Enough evidence has been presented in the thread. No definitive proof, but evidence.

On the other hand, you have not presented any evidence whatsoever suggesting that O2 is not narcotic at recreational depths. You really do need that to make a point. A theory must be considered plausible until it has been proven either right or wrong. Lack of a proof is not proof of the opposite.

 

[gianaameri]

If O2 is narcotic, then it's always narcotic.

Not on SCUBA.

Gases and physiology on SCUBA is a complex matter, yet not completely understood.

Circumstances and environment are relevant.

 

[nimoh]

It is a statement of fact, not an argument.

There is no evidence that O2 is narcotic at recreational depths = O2 is NOT narcotic at recreational depths.

I never stated "only nitrogen causes narcosis" - such statement is NOT true (and NOT mine) because there is evidence O2 is narcotic outside recreational depths (i.e. at 1.65 pPO2 science says there is a 10% impairment).

Please stop running around like brainless chicken and face some simple facts of life. If you can't handle that fact that no evidence exist to support the (erroneous) belief O2 is narcotic at recreational depths, stop posting, as it is not productive (or if you post do not do so to twist around my statements).

in order to be a statement of fact, it must be verifiable, and it is not. So, it it is not a statement of fact, and not an argument, then it must be a joke.