Nitrox and Oxygen Toxicity

[DPJ]

I recently completed a Nitrox class and have read one article on DAN's website about oxygen toxicity ("OXTOX: If You Dive Nitrox You Should Know About OXTOX "). The article from DAN, appears to be based on older studies and involving military divers. I have done searches on this board and and the internet and have been unable to locate other data on the topic.

As I consider the benefits versus rewards of Nitrox, I wonder if there is any more recent data available.

Has anyone seen any reports or statistics on oxygen toxicity and recreational diving?

 

[Rick Inman]

I recently completed a Nitrox class and have read one article on DAN's website about oxygen toxicity ("OXTOX: If You Dive Nitrox You Should Know About OXTOX "). The article from DAN, appears to be based on older studies and involving military divers. I have done searches on this board and and the internet and have been unable to locate other data on the topic.

As I consider the benefits versus rewards of Nitrox, I wonder if there is any more recent data available.

Has anyone seen any reports or statistics on oxygen toxicity and recreational diving?

I'm not sure what kind of stats you're looking for, but there are tid-bits on oxtox all over the board, if you are willing to search for them. Like this thread: http://www.scubaboard.com/t57877-.html

Maybe a more specific question. Like, how much more risk is there really for an average diver at 1.6 vs. 1.4? Whatever. Ask what you really want to know.
Just a thought...

 

[MechDiver]

As I consider the benefits versus rewards of Nitrox, I wonder if there is any more recent data available.

Has anyone seen any reports or statistics on oxygen toxicity and recreational diving?

The risk of oxtox for a recreational diver on 32% or 36% is very low, assuming depth control and the ability to know exactly what mix you are diving.

Oxtox becomes more of an issue when using high EAN and oxygen to accelerate deco for those of us who do such things

Watch your MOD, monitor your depth, know what mix you are diving. No problem

MD

 

[DPJ]

Recreational limits recomend staying below 1.4 PPO, but some of the information in the DAN paper showed instances at 1.1 PPO.

Have there been reported cases in recreation diving when staying within 1.4 PPO?

 

[Charlie99]

If you review the many ox tox incident reports, it becomes obvious that the most significant danger in real life is some sort of gross error or omission that causes you to breathe something other than what you think you are breathing:

Improper mixing of nitrox followed by not bothering to analyze the gas.

Tanks swapped around due to mislabeling or no content labels.

Breathing a deco mixture at depth rather than backgas.

-----------------

I worry about the gross mistakes rather than the few tenths of percent disparity between analyzers that is inevitable.

 

[Walter]

I'm left wondering if there's a question or a point hidden in the original post.....somewhere....

 

[Doc Intrepid]

The question is:

Has anyone seen any reports or statistics on oxygen toxicity and recreational diving?

The answer is: No.

This is not to state categorically that such studies do not exist.

However, I suspect you will not find any. For the reasons that Mech and the others stated.

The number of reports of incidents of recreational divers suffering from oxygen toxicity while performing No-Decompression Limit (NDL) recreational diving while using EANx - if any exist - are most likely statistically insignificant.

That isn't to say that its impossible. Theoretically you could fill your tank with EAN50, which is PO2 of 1.6 at 70 fsw, and then dive it to 90' or 100' - uh, accidentally - because you are a dumb$hit. As Charlie noted above, however, while that might result in oxtox its really a case of breathing the wrong gas at the wrong depth.

Thus, it isn't likely to occur real often. It would be difficult to draw any meaningful empirical conclusions from any study done of perhaps 1 or 2 incidents worldwide.

It isn't something to lay awake nights worrying about.

FWIW. Safe diving,

Doc

 

[DPJ]

The question is:

The answer is: No.

This is not to state categorically that such studies do not exist.

However, I suspect you will not find any. For the reasons that Mech and the others stated.

The number of reports of incidents of recreational divers suffering from oxygen toxicity while performing No-Decompression Limit (NDL) recreational diving while using EANx - if any exist - are most likely statistically insignificant.

That isn't to say that its impossible. Theoretically you could fill your tank with EAN50, which is PO2 of 1.6 at 70 fsw, and then dive it to 90' or 100' - uh, accidentally - because you are a dumb$hit. As Charlie noted above, however, while that might result in oxtox its really a case of breathing the wrong gas at the wrong depth.

Thus, it isn't likely to occur real often. It would be difficult to draw any meaningful empirical conclusions from any study done of perhaps 1 or 2 incidents worldwide.

It isn't something to lay awake nights worrying about.

FWIW. Safe diving,

Doc

Thanks Doc.

I had done some pretty extensive searches, but wanted to see if anyone on the board had seen anything else.

 

[ScubaNorth]

I'm left wondering if there's a question or a point hidden in the original post.....somewhere....

Looked to me like the DPJ was looking for some further education. Also looks like DPJ found a real good answer or two. The question is the sentence with the "?" after it.

 

[padiscubapro]

The question is:

The answer is: No.

This is not to state categorically that such studies do not exist.

However, I suspect you will not find any. For the reasons that Mech and the others stated.

The number of reports of incidents of recreational divers suffering from oxygen toxicity while performing No-Decompression Limit (NDL) recreational diving while using EANx - if any exist - are most likely statistically insignificant.

That isn't to say that its impossible. Theoretically you could fill your tank with EAN50, which is PO2 of 1.6 at 70 fsw, and then dive it to 90' or 100' - uh, accidentally - because you are a dumb$hit. As Charlie noted above, however, while that might result in oxtox its really a case of breathing the wrong gas at the wrong depth.

Thus, it isn't likely to occur real often. It would be difficult to draw any meaningful empirical conclusions from any study done of perhaps 1 or 2 incidents worldwide.

It isn't something to lay awake nights worrying about.

FWIW. Safe diving,

Doc

To add a few things do think about..

There was a study done back in late 40s? (pretty sure), they tested a group of people with oxygen exposures at 5 atas, some were consitently the first to show symptoms several NEVER showed any symptoms even with these extreme exposures.

HSE commercial divers are required to undergo oxygen tolerance tests every 6 months.. the have oxygen exposures of 3.8 atas while doing work.. They are expected to be symptom free for at least 30 minutes.