ppO2 for nitrox, why so low?

[Bowers]

I was parusing some information about oxygen toxicity the other day and came upon this graph:

3-6 hours at 2.0

I have been using tables that set limits based on 1.4 and even my dive computer only allows conservency settings to go as high as 1.6. However for average days of diving at deeper depths i rarely exceed 3 hours in a day, and that is with surface intervals that would allow for "healing" from free radical O molicule damage. So is the data on the graph bogus? Is there another reason for ppO2 levels to be kept around 1.4? or are we diving rediculously conservatively?
Are there any divers who dive greater ppO2 than 1.6? It seems that with 36% nitrox, I shouldnt have any problems going to recreational depth limits of 132ft (1.8 ppO2) for an hour.. (i realize that would most likely be past NDL, but you get the idea)?

 

[CuzzA]

Source of your picture?

It was explained to me, which could be wrong (before my time), the original recommended limit was 2.0, but perhaps some people tox'ed. So then it was 1.6, then 1.4. I'm sure everyone is different. My computer is set at 1.6. YMMV

 

[kotik]

Your main worry isn't lung damage. The main worry is going into convulsions, there is no healing after that. It's not something you'd want to tolerate any significant risk at all.

 

[Bowers]

Source of your picture?

It was explained to me, which could be wrong (before my time), the original recommended limit was 2.0, but perhaps some people tox'ed. So then it was 1.6, then 1.4. I'm sure everyone is different. My computer is set at 1.6. YMMV

diveright.com, author: Dr. K. David Sawatzky

btw what does YMMV mean? lol.
ty

 

[Bowers]

Your main worry isn't lung damage. The main worry is going into convulsions, there is no healing after that. It's not something you'd want to tolerate any significant risk at all.

the graph also shows CNS complications being fairly higher ppO2 or longer times as well.
are you saying we dive extra conservative do to the seriousness of complication we are risking?

 

[CuzzA]

Your mileage may vary.

 

[GJC]

I was parusing some information about oxygen toxicity the other day and came upon this graph:
View attachment 476424

3-6 hours at 2.0

I have been using tables that set limits based on 1.4 and even my dive computer only allows conservency settings to go as high as 1.6. However for average days of diving at deeper depths i rarely exceed 3 hours in a day, and that is with surface intervals that would allow for "healing" from free radical O molicule damage. So is the data on the graph bogus? Is there another reason for ppO2 levels to be kept around 1.4? or are we diving rediculously conservatively?
Are there any divers who dive greater ppO2 than 1.6? It seems that with 36% nitrox, I shouldnt have any problems going to recreational depth limits of 132ft (1.8 ppO2) for an hour.. (i realize that would most likely be past NDL, but you get the idea)?

Where is this from and how old is it?

Is this in reference to divers or hyperbaric oxygen therapy?

 

[Bowers]

Where is this from and how old is it?

Is this in reference to divers or hyperbaric oxygen therapy?

diverite.com, the article is for divers but id guess the data is from hyperbaric treatment studies

Oxygen Toxicity - Signs and Symptoms | Dive Rite

 

[GJC]

diverite.com, the article is for divers but id guess the data is from hyperbaric treatment studies

Link?

 

[Bowers]

Link?

was editing while you were typing lol