SCBA/Cascade Air exchange

[fire06]

Does anyone know how long breathing air is good for? And where to find information on it.
Thanks

[PEMS17]

As opposed to the alternative of not breathing air, I choose breathing air:D

[Toxic]

90 days is the CSA standard for SCBA tanks. I was thinking about this a while back too. I'm sure that the cascade cylinders on our compressor setup aren't emptied and refilled often enough.

[Scuba]

That just changed in the last year or so Toxic - Can't find the standard anywhere online though (big suprise eh?) But I'm pretty sure it's been extended past 90 days.....

[ABFF37]

I think it may be about 6 months now. That's how long we use as our interval for keeping track of the breathing air "freshness". All of our SCBA cylinders get a sticker put on them after they are filled with the date on them. This sticker is checked weekly, and any cylinders that are more than 6 months old are sent back to HQ and swaped for freshly filled ones. The expired cylinders are drained off until there is about 100 or 200 psi left in them, and then recharged, re-stickered, and sent back to the hall.

To be quite honest though it's rare for us to find an expired cylinder, because generally our SCBA gets used a lot, and bottle changes occur much more regularly (after any use at a call, training excercise etc.)

AB

[Toxic]

I stand corrected.

We have the standard here dated 2002. It does not mention a timeline although there is a mention of emptying and refilling cylinders that have not been used in 12 months. NFPA 1981 is also referrenced for firefighting operations. Anyone have access to it?

[LTPVFD]

We used to drain and refill any of our cylinders that had not been used in 90 days. This meant alot of work for our SCBA committee, draining and refilling. :( We have since changed to a 12 month rotation, whereby any cylinder not used in 12 months is drained and refilled.

The WCB and referenced CSA standard is as follows:

(2) If an SCBA cylinder has not been used for a period in excess of one year, air in the cylinder must be slowly depressurized to atmosphere and refilled with compressed breathing air that meets the requirements of CSA Standard CAN/CSA-Z180.1-00, Compressed Breathing Air and Systems.

[Amended by B.C. Reg. 312/2003, effective October 29, 2003.]
[Amended by B.C. Reg. 20/2006, effective May 17, 2006.]

We keep track of fill/expiry dates with a program called SCBA Boss. Everytime you log in, you get a "due list" that tells you what cylinder requires filling, or what equipment requires service.

Stay safe !!


LTPVFD :)

[BCFFFV]

Our dept. considers the air to be expired after 3 months. However it will probably still be fine much longer than that.

[Jon_ACVFD]

yeah, i think its somewheres around 6 months, but we hardly ever have the same air in the Cascade bottles for that long as we are Mutual Aid for the town dept. as well. We go to most of their structure fires (we have the Cascade system), they go to a majority of our MVC (they have auto X gear)

[Airtech]

Not to run off on a tangent guys, but as an air tech i'm curious as to what you think, or believe, happens to air if its past 90, 180 or even 365 days old?

[tmehmel]

I dont think anything changes, however, under our new changes to the workplace health and safety, we have to change the air every six months, so its a dead issue with us.

Tom

[Workingfire]

Not to run off on a tangent guys, but as an air tech i'm curious as to what you think, or believe, happens to air if its past 90, 180 or even 365 days old?

You must be new here....that's hardly a tangent by our standards!

[Ruckus]

You must be new here....that's hardly a tangent by our standards!

Besides, if a tanks been sitting still for 90-180-365 days it's probably a good idea to dump and refill it even if to only exercise the valve :)

[Airtech]

I totaly agree, with exercising the valve and, by fresh air is great. I issue is with the way this standard seems to jump up and down frequently, 90 day, 365 days, 180 days. We spend more time trying to track the standard, than we do actually abide by it.

[Blacknose]

Not to run off on a tangent guys, but as an air tech i'm curious as to what you think, or believe, happens to air if its past 90, 180 or even 365 days old?


Just a thought...At a molecular level, does the composition of the air in a bottle change over time?

As an example, helium in a balloon will deplete over time, because the helium molecules will escape from between the balloon molucules. This could happen to BA bottles, if my memory serves me correctly, when I took my welders courses 20 yrs ago I was told that oxygen/accetelene bottles will lose pressure over time even if the bottle is sealed.

I know we have had tanks that sat for a long time and the pressure has diminished to some degree. I have always thought the valve has passed, now I don't know for sure.

Has anyone done an air quality comparson test on a stale tank vs a fresh tank?

[DFCSmash]

As long as there is NO corrosion in the bottle, meaning no-one ever drained it down to atmospheric pressure an left it open, the air won't really change. If, however there is any corrosion, oxygen levels would decrease would they not?

After about 6 months, the air goes "stale" for want of a better term, and has a smell and taste to it. It's still 100% safe and usable, and certainly beats not breathing bottled air at any event!

[Toxic]

I would argue that having air in a cylinder too long would result in a change in consituents.

In a steel tank corrosion and a reduction in O2 could certainly be an issue.

In a composite tank I would argue that some chemical compound may be released in minute concentrations that could eventually accumulate to a concentration that may or may not be hazardous, but still be something I would choose not breathe. Paranoia? Maybe; but lots of other things we used commonly are now dangerous. (sorry - just got back from doing an asbestos presentation):)

It's not that hard to change air every 12 months...