Is nitrox worth it for deeper rec dives?

[Storker]

my ass, my conservatism

I think I might write this in big, bold, fluorescent letters somewhere. Perhaps on my wing.

 

[Manatee Diver]

Manatee Diver, Just to be clear, the time limits you are quoting are for pulmonary oxygen toxicity, which causes lung issues, where we have somewhat understood factors of partial pressure and time.

The issue generally of concern as you approach 1.4/1.6 is central nervous system toxicity, which causes convulsions, where all the factors are less understood, so people draw a line at partial pressure. But as most lines, it is fussy and time and others seem factors, but no precise numbers are know. But the 45 minutes at 1.6 is about pulmonary toxicity, CNS toxicity may cause convulsions way before that depending on you, what you're doing, how well your day is going, ...

Edit: Low N2 makes a wider NDL buffer more convenient. Convulsions are really bad. I work at low N2 while staying a decent margin from convulsions.

The NOAA numbers I quoted are for CNS, not for pulmonary issues as that is more about long term exposure over a period of days. I don't completely understand how the NOAA calculates OTU as I don't feel it is concern for the type of diving I do (2-3 days of rec diving with breaks of at least 2-3 days between them).

I do find the PADI EAD manual to be somewhat sparse as in "this is what you need to know to pass our exam and not much more."

That said, my ass, my conservatism.

Pretty much my opinion of the PADI EAN manual. But I agree, we each need to decide our comfort level, and stick to it.

 

[yle]

I can't believe this is even a question....

OF COURSE WE DO! Dumbing down mixes with air has never been an issue, nor would it be. Not once did we say we didn't, and there is not a soul here who would even think of saying something like that. I'm sorry, but this comes from confusion from the OP on what is going on and not fully understanding blending.

I got the impression that the OP interpreted the "O2 clean tank" requirement for "partial pressure blending" to include diluting the 32% banked. Simply a misunderstanding of the jargon... compounded by her defensiveness of the misunderstanding.

 

[yle]

But I do believe that excessive O2 is bad for you because, unlike N2, oxygen is not chemically inert and it damages DNA and other vital molecules in our cells.

Oh goodness... apparently nitrox increases the risk of DNA-altering mutations.

I smell a conspiracy... cert agencies, naturally, are trying to suppress this vital information by excluding it from their nitrox course materials. The truth, no doubt, is on YouTube.

 

[tarponchik]

You know what they say about opinions? They're like arseholes: everyone has one.

Sure. I am a big fan of Clint's movies too. Is there anything else you might contribute to the dialogue?

 

[Storker]

Is there anything else you might contribute to the dialogue?

Sure. It's even on topic.

As long as I do not get DCS, I do not care about N2 loading.

That's your choice. I happen to disagree.

 

[tarponchik]

Oh goodness... apparently nitrox increases the risk of DNA-altering mutations.

I smell a conspiracy... cert agencies, naturally, are trying to suppress this vital information by excluding it from their nitrox course materials. The truth, no doubt, is on YouTube.

No conspiracy. There is just not enough data for any deciesive statements coming from CDC, FDA or scuba agencies. But there are valid reasons to suspect that indeed, breathing Nitrox should increase mutation rate and/or kill cells. So we are in the grey zone here, just like with taking antioxidant supplements.

 

[ChuckP]

I do find the PADI EAD manual to be somewhat sparse as in "this is what you need to know to pass our exam and not much more."

That said, my ass, my conservatism.

Basic nitrox classes are just that, basic. You certainly learn what you need to know - taking what you learn and doing some math, you'll see that it's darn hard to get yourself to the OTU limits.

Advanced Nitrox classes add more to it, deco class more and tri mix even more so - I think it's a great system of step learning in that it doesn't overwhelm you with information that may not apply at certain levels of diving but the math is there.

 

[yle]

There is just not enough data for any deciesive statements coming from CDC, FDA or scuba agencies. But there are valid reasons to suspect that indeed, breathing Nitrox should increase mutation rate and/or kill cells.

Yeah... I really don't think there are. The only truly valid reason would be a measured statistical difference in the mutation of those that breathe enriched air compared to those that don't. Any other reason is just plain silliness.

By your own admission, that measurement doesn't exist. And if it's a belief thing... why not simply believe that using nitrox only causes beneficial mutations? Not all mutations are harmful.

 

[tursiops]

No conspiracy. There is just not enough data for any deciesive statements coming from CDC, FDA or scuba agencies. But there are valid reasons to suspect that indeed, breathing Nitrox should increase mutation rate and/or kill cells. So we are in the grey zone here, just like with taking antioxidant supplements.

The really scary part here is not concern about Nitrox altering one's DNA, but rather that you might actually be serious.