Should Nitrox tanks have the percentage clearly listed?

[Sounder]

I think the biggest reason it's "required" to have a tank "wrap" sticker is because the dive shops can get them cheap and sell them with a fairly healthy profit margin. There is no federal law requiring them.

The post is well taken... all my deco bottles are nitrox (haven't reached the level that involves trimix deco mixes) except for the O2 bottles which, I guess is just "ox" even though it's part of "Advanced Nitrox." More importantly, to me, is the MOD markings on my deco bottles... that's real information. I still analyze, and I still write it on white duct tape in Sharpie on the top of the tank (I might have 49.5% or 50.5% or something in my 50%/70fsw bottle, and I like knowing this), but the MOD stickers tell me (and my buddies) what depth is safe to breathe that gas at... and my MOD stickers are highly reflective black-on-white for ease of reading.

What does the green and yellow really tell you? It says "Enriched Air Nitrox" or "Nitrox" or something like that... ok, go with that. What is in there? 40%? 32%? 28%? 36%? See, the tank STILL needs to be analyzed.

I suppose the one thing it tells you is, in theory at least, that the tank may be clean enough to partial-pressure blend with oxygen to get the desired nitrox mix... in other words, it "may" be O2-clean. If it's been filled with non-OXYGEN-clean gas, technically it could be considered as no-longer O2 serviced. Then again, if the fill is from a membrane blending stick, as many shops are pumping, then it doesn't need to be "O2 cleaned" in the first place. Of course, the big honkin' yellow and green sticker isn't generally where the "oxygen clean/oxygen serviced" indication is anyway... generally, that's on the vip sticker. So again, all those stickers tell me is the words reading: "Enriched Air Nitrox" or "Nitrox."

For me, I fill off oxygen-clean compressor/bank systems which are usually pumping banked 32% for my recreational diving. When I have to fill elsewhere, I take the tanks closest to vip because I like to keep stuff O2-clean so I'll just re-clean them upon my return.

So, to turn your question around... what exactly DOES a "nitrox" or "enriched air nitrox" sticker tell you? Why IS it necessary? Why IS it sold to so many people when they're buying tanks?

[CaptnJack]

For you who dive both Air and EAN in both Bannered and Plain Cylinders:

The shop/boat fills both Air and Nitrox. You have asked for Air. If you only analyze Nitrox cylingers how do you know you got Air and not Nitrox in some percentage?

You don't. Shops "should" have air customers analyze air tanks. Although to date I don't think there has been a single incident worldwide due to getting nitrox in an air tank. Although "some percentage" of extra O2 due to the inadequate purging of whips etc. is really never going to amount to a hill of beans.

I have no banners and my single tanks are not O2 cleaned either, I continuous blend 32% into those.

[Tom Nic]

I think the biggest reason it's "required" to have a tank "wrap" sticker is because the dive shops can get them cheap and sell them with a fairly healthy profit margin. There is no federal law requiring them.

I've never been charged for a "wrap" sticker, 2 dive shops and counting. And no, they didn't have the name of shop on them.

Biggest thing that makes me want to not have them is potential pitting issues - though I've had people tell me "no, that's never a problem!" Not sure I buy it.

And in fairness, I don't think any shop promoting a "wrap" sticker would also be saying, "therefore don't analyze". You analyze your tanks. Period.

But in a shop environment, with newer divers, and a fair amount of potential chaos, a very clearly marked tank would be a plus as far as having an untrained, newer, or unobservant diver pick up a tank and use it without a clear understanding of what they were breathing. I'm guessing that's the reason.... and again, that lawyers are involved. Big sticker = "I had no control over the fact that they were idiots and breathed the wrong gas - see the sticker? You can't sue me!"

[Sounder]

I think the biggest reason it's "required" to have a tank "wrap" sticker is because the dive shops can get them cheap and sell them with a fairly healthy profit margin. There is no federal law requiring them.

I've never been charged for a "wrap" sticker, 2 dive shops and counting. And no, they didn't have the name of shop on them.

Biggest thing that makes me want to not have them is potential pitting issues - though I've had people tell me "no, that's never a problem!" Not sure I buy it.

And in fairness, I don't think any shop promoting a "wrap" sticker would also be saying, "therefore don't analyze". You analyze your tanks. Period.

But in a shop environment, with newer divers, and a fair amount of potential chaos, a very clearly marked tank would be a plus as far as having an untrained, newer, or unobservant diver pick up a tank and use it without a clear understanding of what they were breathing. I'm guessing that's the reason.... and again, that lawyers are involved. Big sticker = "I had no control over the fact that they were idiots and breathed the wrong gas - see the sticker? You can't sue me!"

I've seen them for sale for as much as $25 per wrap when NOT buying tanks, though I'm not surprised they "included" them with your tanks... they're like $3 or $4 max to buy if you know where you're going. I think most of it goes back to "that's the way we've always done it."

As far as lawyers are concerned, there is no law saying they have to have it and there are plenty of expert witnesses who will testify that "the stickers tell you nothing and shouldn't be used at all because they could cause complacency... and that the pitting they cause actually creates MORE of a liability." It's a stretch, but I don't believe the sticker provides a viable defense at all. What if a newb grabs my tank by mistake that is properly analyzed and marked with the gas content, but it doesn't have a nitrox sticker... am I at fault? Don't think so.

Take it a step further... Air is 21%... which is technically "nitrox." Shouldn't ALL tanks have a wrap then?

I don't care if it's air, trimix, O2, or nitrox... I'm analyzing.

The most critical thing to remember is, however, that chicks dig bald tanks.

[airsix]

So to sum up:
1) stickers are worse than useless
2) make no assumptions
3) analyze every time

A while back I heard about a guy who's tanks are just marked with a big sticker that reads "THIS IS NOT YOUR CYLINDER".

[lamont]

re the "Big Green Banner" -- I, and I suppose most of us, have heard that it is "required by Federal Law" to have such a sticker. Do any of you know what "Federal Law" (I'm supposing a CFR # here) requires such -- or at least purports to require such?

i think the CGA guidelines for O2/N2 mixes other than air, is a black and white checkerboard on the tank neck...

i thought the bumpersticker was borrowed from NOAA science diving...

and in reference to the other question, it tells you nothing useful...

- analysis stickers on the neck tell you what was analyzed to actually be in the tank.
- an MOD bumper sticker tells your team where it is safe to breathe the gas
- the VIP sticker can tell you if it is O2 clean

the sole purpose of the bumpersticker is to keep non-nitrox certified divers away from nitrox tanks. with nitrox in the mainstream now, this is less important -- and there's zero chance of having a non-nitrox cerftified recreational diver pick up my doubles and go diving them accidentally...

[CaptnJack]

i think the CGA guidelines for O2/N2 mixes other than air, is a black and white checkerboard on the tank neck...

I thought that was EU's requirement? (not CGA)

Any non-nitrox diver picking up my hp100s and diving them significantly below the MOD of 32% has bigger problems to worry about. ppO2 of of 1.4 is 112ft and 1.6 is 132ft afterall.

[defied]

So to sum up:
1) stickers are worse than useless
2) make no assumptions
3) analyze every time

A while back I heard about a guy who's tanks are just marked with a big sticker that reads "THIS IS NOT YOUR CYLINDER".

I think I remember seeing those stickers on someones bottles.

D(B)

[lamont]

I thought that was EU's requirement? (not CGA)

i could very well have that confused.

point is still that no government regs cover the nitrox bumper sticker.

[airsix]

- analysis stickers on the neck tell you what was analyzed to actually be in the tank.

I'd edit that to read: analysis stickers tell you what was analyzed to actually be in the tank at some point in the past. I've picked up cylinders that still had the prior-fill's sticker on the neck.

[CaptnJack]

I'd edit that to read: analysis stickers tell you what was analyzed to actually be in the tank at some point in the past. I've picked up cylinders that still had the prior-fill's sticker on the neck.

The standard for tech diving is that you analyze and date the tank TODAY before breathing it. Hence every tech diver needs an analyzer, tape, and a pen. Since I have my own fill station, I have modified this standard to be "I have analyzed it before its loaded for transit to the divesite" which might be the night before. And tanks never ever get loaded if the MOD stickers "oxygen 20", "70" and "120" don't match up with the contents. Most divers using a shop are fine analyzing and labeling before leaving the shop, which is 90% of the reason for their logbooks. If you do alot of transfilling between tanks/mixes you need you own analyzer to confirm what's going on.

[airsix]

That's good.

I just meant don't assume anything just because the neck is marked unless you put it there and it hasn't left your possession since.

[lamont]

that is why the analysis sticker needs a date on it.

[airsix]

that is why the analysis sticker needs a date on it.

...because you can only fill a cylinder once per day. :pinch: (JK)

[ArcticDiver]

For you who dive both Air and EAN in both Bannered and Plain Cylinders:

The shop/boat fills both Air and Nitrox. You have asked for Air. If you only analyze Nitrox cylingers how do you know you got Air and not Nitrox in some percentage?

You don't. Shops "should" have air customers analyze air tanks. Although to date I don't think there has been a single incident worldwide due to getting nitrox in an air tank. Although "some percentage" of extra O2 due to the inadequate purging of whips etc. is really never going to amount to a hill of beans.

I have no banners and my single tanks are not O2 cleaned either, I continuous blend 32% into those.

I don't generally analyze cylinders that have been presented to me as air either. But on my last dive trip I noticed the whips for air and banked 32% were side by side and had well used labels. The gas source for each whip was some 100' away in a room not directly visible by the person filling cylinders. Also, I remember on a previous trip to another location I tailored the mix to the anticipated profile of each dive. Percentages ranged from 29% to 55%. Other than my analysis marks there were no other content indications on the cylinders. I thought how easy it would be for the shop that had literally hundreds of cylinders to get confused.

Like you I haven't heard of any accidents/incidents caused by nitrox/air confusion. Or, even due to mix percentage confusion. For folks that always dive some sort of mix this definitely is a non-issue. But, for folks who dive air since we don't have formal accident investigation protocols there is the niggling idea that maybe some bad results have been overlooked.

[CaptnJack]

Yeah I don't dive best mix so these 28% vs 55% cylinders are really a foreign concept to my tanks.

[LCF]

Yeah, one of the advantages to standard gases is that my shop knows there are very few things that will be in my tanks. At the moment, that's 32% or 25/25 in anything bigger than a 40.

I don't always analyze the day of the dive. But we analyze before we leave the shop, and the tags are dated -- if the tank gets used in the meantime, the original psi on the label gets crossed out and rewritten. And if the tank is transfilled, it gets reanalyzed and the new contents get put on. I do take this stuff seriously, although my personal hard deck is shallower than the MOD of anything that is SUPPOSED to be in my main tanks (and nothing else has ever been there).

[Pinkpadigal]

The most critical thing to remember is, however, that chicks dig bald tanks.

Sorry Doug...this chick likes banded tanks.

You have 25-30 tanks to fill, banded tanks make life easy when trying to figure out what needs air and what needs EAN. It is also nice when you have a bunch of tanks in the back of a vehicle and being able to tell who's who's with a quick glance, rather than looking for a vip sticker.

I am not a stickler for tanks being banded. However, since most of the tanks I see are for recreational depths, it is rare I see one not banded. I do like to take the percentage out a decimal point though. I also like to initial and date my tanks, just so I know when I filled and analyzed it.

As for the cost of band stickers, I have never seen them sold for more than $2-3. Maybe the yellow on the $40 stickers is a new type of tank bling with real gold on it. :luv:

[ArcticDiver]

Yeah, one of the advantages to standard gases is that my shop knows there are very few things that will be in my tanks. At the moment, that's 32% or 25/25 in anything bigger than a 40.

...

Yep, standard mixes sure do make life easier. I usually do that too. But there are occasions.... Plus, it is a real life example that illustrates my question.

[Grateful Diver]

Amy points out the real reason for those banners ... they are not for the benefit of the diver, but for the benefit of the dive shop employee filling tanks, or the guy on the boat sorting through rental tanks for a dozen different divers. Here in the PNW almost everyone owns their own tanks, and is bloody well aware of what they look like and which ones are theirs. The chances of accidentally picking up someone else's tank is almost nil.

Fast forward to Cozumel for a moment, on a boat with 25 people you've never met before (the way most of the world dives) and what we take for granted suddenly doesn't hold up anymore. You've never seen the tanks you'll be diving before ... and the boat crew who's busily swapping everybody's tanks (because they do it for you in most destination resorts) doesn't know your tanks from anybody else's. In that case, banners on nitrox tanks make sense.

Different needs for different environments ... that's what a lot of us always forget in these conversations. A lot of things make sense in particular environments, but for one reason or another get carried over into environments where they don't. This happens to be one of them.

The "federal law" stuff is funny though ... I remember years ago being told the same thing by the same person. I suspect he actually believes it ...

... Bob (Grateful Diver)

[Sounder]

As far as telling who's tank is who's, mine all have my last name with a number... And none of them have air in them. My tanks get filled with what I request to have put in them. How does the tank filler know who wants 32%, 36%, or 40%? The band is the same, so it STILL needs to be labeled with what the customer wants in it.

In Bonaire, where the world of lax-care on tank management, all the "nitrox tanks" had indications they were once stickered... But now they're all bald just like the air tanks. Those with air are labeled in blue paint and those with 32% are labeled with green paint... and you only get one or the other, and you still analyze and mark the tank in tape... So the big honkin' wrap clearly isn't necessary there either. The only reason they're marked at all is for the ease of managing 200 tanks and two gasses. I get this, and I like their system... but it still doesn't require a wrap, even in those extreme circumstances.

When I asked them about it, they didn't replace the stickers because the tanks were pitting due to the stickers.

[Mongodives]

I like the banners for recreational diving, It makes it easy to identify air from mix in the back of the truck.
IMO Even if you don't use the band the VIS sticker should clearly state if the tank was cleaned for premix to 40% or O2 clean. I can't remember if that is what I was taught or regulatory guidance, since I think its a good idea I'm not going to dig through my references to check.

My preferred method is;Tape with date, %, MOD and initials on tank then removed after tank is used.