Is old air safe?

[Basking Ridge Diver]

Don't SCBA and other one atmosphere based consumption of compressed air have a vastly reduced risk of ill effects due to contamination? I'm pretty sure 15ppm CO in an SCBA tank is not going to be life threatening. 15ppm CO in a scuba tank at 120' - I'm not so sure about that.

Absolutely - agree and that is why I say test it... but don't dump it especially if it is a 4 hour round trip to go get it checked and filled... I would prefer 0 ppm myself...

 

[grf88]

That "new" oxygen and nitrogen was not created by those processes but just released

 

[Milkman670]

My pool isn't quite that deep

 

[nadwidny]

FWIW the Canadian standard for compressed breathing air is that a cylinder must be dumped and refilled after a year. I don't know why CSA picked that time period.

 

[NAM001]

There is only one answer. If you don't know what you have in the tank dump it and fill it so you do know. Onky you are responsible for what you breath.

 

[lermontov]

I have done it. Don't recommend it though. I didnt know what i didnt know.

Is your life worth a $6 fill and vis inspection? Drain it, get it vip'd, fill it up and dive it.

this

 

[scubafanatic]

Stick a reg set on it, do a few test breaths on dry land, if it seems OK, I'd just dive it. The odds of that 2 yr 'old' air being any more or less trust worthy than 'brand new air' are pretty low...either you trust the filling dive shop...or you don't.......for all you know, it could be a 'new' fill that's contaminated, unless you trust that shop, which you do. If you have an nitrox analyzer, no harm in running a quick check for O2 %....quick and easy.

 

[lerpy]

Yes, I would do the drive and get the tank dumped and inspected and re-filled. It's a safety thing. Personal opinion if you start taking short cuts or side stepping some aspects of safety, you will be willing to side step others. Bad practice to get into.

 

[Freewillow]

I personally would test the 02 content and smell it. if it is odorless and 21% 02, go for it

 

[DA Aquamaster]

I agree. If it does not have an odor or taste and the O2 percentage is correct for what is marked on any contents label, I'd dive it, given that you know the tank's former owner and it was filled by a reputable shop.

You don't have any reason to suspect a problem and quite frankly you're probably taking a greater risk of injury driving 4 hours to/from for an "extra" trip to the shop to get it re-filled. Use the tank, then take it in for a fresh VIP and fill next time you're going to the shop anyway.

We leave AL stages in storage in FL and since they are bailout gas, they may sit a long, long time before they are actually used. I brought one home after the last trip to FL as it's now out of hydro, and I'm using that "old" nitrox before I empty the tank to get it hydro tested.