Nitrox tank labeling

[PfcAJ]

1.2-1.4

 

[djtimmy77]

I don't write MOD on the tank, only the mix. That being said, I typically dive well below 1.6 but don't have an issue of going to 1.6 for short periods of time.

 

[Nasser]

NDL dives 1.4 or 1.5
Tech dives 1.4 for bottom mix and 1.6 for deco

 

[dalpe933]

NDL dives 1.4 or 1.5
Tech dives 1.4 for bottom mix and 1.6 for deco

Same here! 0.8 is overkilling the safety margin!

 

[scubadiver888]

DAN had a workshop back in 2000 (https://www.diversalertnetwork.org/files/DANnitrox_web.pdf) and one of the findings from this (page 19) was:

When the oxygen set-point was raised to 1.4 atm, there was no DCS in 17 no-decompression dives to 100 fsw for 40 min and 1.7% DCS in 58 decompression dives to 100 and 150 fsw for 60 min. At an oxygen set-point of 1.6 atm, there was no DCS or oxygen toxicity during 13 no-decompression dives to 150 fsw for 10 min, but an oxygen convulsion occurred after 40 min during a single dive to 100 fsw (40% F1O2). The diver had exercised underwater at a measured oxygen consumption of 1.6 Lpm and noted high breathing resistance that was confirmed during post-dive tests.

This is why agencies like PADI recommend a ppo2 of 1.4. At least this is what I was taught when I got my EAN certification.

 

[claymore]

I mark my Nitrox tanks with the O2 mix, the MOD for 1.4 and the Contingency depth at 1.6. The reason I put the Contingency depth at1.6 is that my shop banks 32% and some of the sites I dive have bottoms below 111' so that if there is a hiccup in the dive plan I know I can go deeper with a margin of Saftey.

Several of the instructors I know have said that they do not have a problem using 1.6 for rec diving.

 

[NAM001]

I wish i had the references handy but ill wing it. ppo2 of 1.6 is ok when you get to ie 1.7 the effects no longer remain linear with ppo2. Ie the effects are (for sake of argument) twice that of 1.6 when you get to 1.8. and 2.0 would be 3 times that of 1.8. so although 1.6 is considered safe math wise a buffer is put in play at 1.4. Now if you are planning your dive for max of 1.4 and your depth drifts another .2 then you go from 1.4 to 1.6 as opposed to going from 1.6 to 1.8. This exact thing happen to me on the oriskiny. my alarm went off and i was at 1.78. something was not right about seing the flight deck with 32%. So things do happen. when you get to tech level you plan for a max of 1.4 and accept 1.6 when on deco gas. There are reasons for this and they are centered around time of exposure and other factors. So if you are diving at 1.4 and you drop your flash light and go to get it and find your self at 1.5 it is not a panic situation.

 

[DuboisP]

You are fine with 1.6 - although the standard is 1.4
The idea is that if you use 1.4 and you dive a little deeper on accident you still have 0.2 as a buffer. But if your responsible and pay attention you can use 1.6 as a hard MOD. Some even push past 1.6 but that's not smart.

or the inverse
label with 1.6 and dive higher.

 

[Oldbear]

When filling out the MOD info on the label at the dive shop, which MOD do you use PO2 1.4 or 1.6? I've been reading different messages and most say they use PO2 of 1.4 where my instructor said to use 1.6.

Any thoughts?

I suggest that you re-read your EAN Specialty book and fine out exactly what the MOD is for, how it is calculated and how to apply it to diving...your type of diving. You have just received suggested MODs from 1.2 - 1.7 in the above threads and all of them are valid options; based on what you read which MOD is best for you?

 

[TotDoc]

1.6 is generally considered safe, but it is best to plan your dive based on a 1.4. That way, if you end up finding that you need to go a little deeper than you had initially planned, you still have some wiggle room in your safe max depth. Plan on 1.4, but use up to 1.6 for contingency needs...like recovering a flashlight or camera, for example