Narcosis Properties of Different Gases

[gianaameri]

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.

Evidence has indeed been presented on the thread that O2 is narcotic beyond recreational depths where 1.65 pPO2 = 10% impairment.

No evidence has been presented that O2 is narcotic at recreational depths.

"O2 is narcotic at recreational depths" is a "belief" without proof. A dogma. A mantra. Bull-s. - an unproven hypothesis at best.

 

[victorzamora]

One of the reasons that O2 toxicity (Did you mean narcosis??) has not been tested in isolation is related to O2 toxicity. To test effects in isolation, you have to test the gas at high partial pressures--where it can be shown to be the primary inducing agent. You can test the narcotic properties of nitrogen by putting people in a very high PPN2 and seeing the results. If you put people at a high PPO2, they tox.

My point wasn't whether or not people suffer narcosis before toxing, my point was simply that translating chamber rides to actual dives doesn't work as easily as people would think. People tox out in the water with MUCH less PPO2 than in a chamber, consistently.

 

[nimoh]

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

<sarcasm>
although it should be taken as fact that oxygen is NOT narcotic at recreational depths, since this is the only part that is completely understood.
</sarcasm>

 

[boulderjohn]

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

Lack of a proof is not proof of the opposite.

Correct. Aristotle would be shaking his head in despair if he could hear that leap of logic.

The reason we have no evidence of oxygen being toxic is because of the challenges of testing it. As I said in at least one of the threads on this topic, we know that people get narced at recreational depths. We know that nitrogen contributes to this because we are able to test subjects at high PPN2 and low PPO2, which isolates it. We cannot isolate O2 that way because a high PPO2 and low PPN2 leads to toxicity. We therefore cannot prove the degree to which O2 contributes to the problem through experimentation of that kind.

We do have a pretty solid theory of what causes narcosis, a theory that holds true for all gases that we can test the way we test nitrogen. It is therefor extremely likely that it would hold true for oxygen, which we cannot test the way we do nitrogen.

It might be possible to create a test that would isolate oxygen to measure its narcotic potential, but I doubt if any scientist would bother with it because it seems so bloody obvious to 99.9% of the diving world. You don;t go to great expense and effort to prove something that appears to be patently obvious unless there is a compelling reason to do so.

 

[gianaameri]

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.

It is verifiable that no evidence exist that O2 is narcotic at recreational depths.

None exist. If you have some, please provide title of the study, author, and publisher.

 

[boulderjohn]

My point wasn't whether or not people suffer narcosis before toxing, my point was simply that translating chamber rides to actual dives doesn't work as easily as people would think. People tox out in the water with MUCH less PPO2 than in a chamber, consistently.

Yes--I meant narcosis--I have edited the original to correct that.

I only quoted you for context--it was not a comment on your point.

 

[dfx]

Evidence has indeed been presented on the thread that O2 is narcotic beyond recreational depths where 1.65 pPO2 = 10% impairment.

No evidence has been presented that O2 is narcotic at recreational depths.

Right, so you acknowledge the truth of the bolded part. Paraphrasing it:

X is true under certain circumstances.

Your deduction from that is:

X is not true under other circumstances.

This is a logical fallacy: Denying the antecedent - Wikipedia, the free encyclopedia

You have no point, none whatsoever.

And I'm saying that without even having a horse in this race.

 

[boulderjohn]

It is verifiable that no evidence exist that O2 is narcotic at recreational depths.

None exist. If you have some, please provide title of the study, author, and publisher.

Has there been a single test to show that oxygen is not toxic? Can you cite it?

There has not been a test to show that there are iron deposits in the core of the moon. That does not mean there is none there.

 

[victorzamora]

Not on SCUBA.

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

Circumstances and environment are relevant.

One thing you seem to be missing is the difference between narcotic effects and impairment. If oxygen can be narcotic, it can always be narcotic. The narcotic effects or impairment may change, the ppO2 at which impairment starts becoming noticeable, the risks associated with said impairment, etc.....all of that can change, yes. But whether your body treats high ppO2 as a narcotic agent or not is a constant. How is your body to know whether you're in a cave at 100' with low viz, or the Maldives at 100' with a mile of vis? It won't. Also, how is it that at 130' O2 isn't narcotic, but at 131' (out of rec depths) it is? The impairment and risk changes, and your body's reaction changes, but whether or not O2 has narcotic properties is a constant.

 

[gianaameri]

Has there been a single test to show that oxygen is not toxic? Can you cite it?

There has not been a test to show that there are iron deposits in the core of the moon. That does not mean there is none there.

Right, so you acknowledge the truth of the bolded part. Paraphrasing it:

X is true under certain circumstances.

Your deduction from that is:

X is not true under other circumstances.

This is a logical fallacy: Denying the antecedent - Wikipedia, the free encyclopedia

You have no point, none whatsoever.

And I'm saying that without even having a horse in this race.

The various comments on this thread do show that we are in the realm/field of theology.

I feel like I am talking with a group of people who firmly believe there is a God.

I say, there is "no proof" that there is a God.

The response is "There is no proof that there is not one... you prove that there is not one..."

This is pure theology and dogma and it supports the fact that there is no evidence O2 is narcotic at recreational depths.