Bad air

[grayeagle]

just recieved my aug, dive training magazine, looking tnrough the articals i stoped to read (breathing fron a contminated tank). the story is so close to what happened to me last weekend at the dive-in in redondo i think my tank is contaminated, how do i find out? i did'nt notice any bad tast eather.

 

[divrdrew]

Completely drain your tank and get it inspected. That should give you an idea if it was your tank or the air. If not your tank, where did you get your last airfill? I'd take it back there and let them know what happened. Is there still bad air in the tank?

 

[grayeagle]

my tank was inspected before it was filled by sport chalet. the tank i got at a garage sale for $10.00 it was used for air gun refill. there is still air in it but if it's bad ? that's my question, do i trust my lds to tell me the is bad? to let everyone else know what happened that did'nt read the artical, i was on my 2nd dive and only 7 minutes down when it got real hard to breath,short hard breaths. this is one of the three that were inspected and filled. this has never hapend to me before and would appreceate any ideas, if you fell it may not have been bad air.

 

[MaxBottomtime]

It could be a number of things, but bad air is not likely one of them. The tube in your tank valve may have come loose or been removed, allowing rust or other contaminants into your valve. Your regulator may have problems, or perhaps the valve wasn't open all the way.
Bad air smells like stale air from a car tire and leaves a burning sensation in your throat. You can tell it's bad as soon as you take the first breath.

 

[TSandM]

Air can be contaminated with any number of things, some of which have odors or tastes, and some of which (like carbon monoxide) do not.

If you are seriously worried about the gas in your tank, you can get it analyzed. I'm not at all sure where you would go in your area to do that, but I'd suggest contacting a toxicologist about it.

 

[saylke]

I was recently wondering about methods to test for CO directly from a tank also also and found this website: Carbon Monoxide tester for scuba and firefighting

According to the website a positive for CO is given when levels reach 50 ppm. In my opinion that is much too high since the standard for Grade E breathing air is 10 ppm. In addition, our exposures during diving would be even higher since we breathe in a larger volume of air per breath at depth.

Another method of testing the air would be to fill up a plastic bag with air from the tank and then sample that air with colorimetric indicator tubes made by sensidyne or draeger. An industrial hygiene or environmental consultant could probably help you with this if you're serious about checking this out. The test would only take about 5 minutes to complete and the tubes for the test only cost about $5 each. These consultants can be found through the ABIH - American Board of Industrial Hygiene or AIHA - Home

Hope that is helpful.

 

[visibilityunlimited]

No Dive store or facility in its right mind would purposely give someone bad air but sometimes it does happen. I do not suggest emptying the cylinder if you suspect you do have bad air as this is like closing the barn door after the horses are gone. I also don't suggest hating the dive store that may have given you bad air. There are quite a number of reasons that a person could get a bad fill. Compressor systems can have problems occur between air tests.I do suggest going back to where you did have it filled (or call them) and talk to them calmly about your concerns. Even if they deny the possibility, I would take bets that as soon as you left they would head straight back to their compressor to make sure that all is well with it. This would also more than likely include an air test of their system. If it was bad air then you will have then become the silent hero by making them aware that there might be a problem and thereby keeping them from unknowingly filling other tanks with it. They definitely won't like hearing that they might have bad air but they definitely act on it.

 

[visibilityunlimited]

I will also add that in my years of doing visuals, I have smelled everything ranging from peppermint to what smelled like having your nose next to a car tailpite sorely in need on emmisions testing.

 

[jiveturkey]

my tank was inspected before it was filled by sport chalet. the tank i got at a garage sale for $10.00 it was used for air gun refill. there is still air in it but if it's bad ? that's my question, do i trust my lds to tell me the is bad? to let everyone else know what happened that did'nt read the artical, i was on my 2nd dive and only 7 minutes down when it got real hard to breath,short hard breaths. this is one of the three that were inspected and filled. this has never hapend to me before and would appreceate any ideas, if you fell it may not have been bad air.

In our shop, valve maintenance is not part of the VIP. Its possible that they didn't service the valve unless you specifically asked them to. Take the tank back to the shop and tell them what happened. They may need to have a second look at your valve.

 

[don Francisco]

I agree with Max B. Based on your description, I don't think you experienced bad air for 2 reasons.

The fiirst is that you had 3 tanks filled at the same time. Most folks fill tanks from a manifold, so whatever was in one tank would be all three. It is possible the air went sour from something inside the tank, but that usually takes a bit of time.

The second is that good, bad or ugly all air breathes the same. The difference between good air and bad is how they support life not how they flow. Your symptomology is more indicative of a flow problem such as a clogged valve, clogged filter in your first stage, or that old classic; a partially open valve, which couldn't maintain sufficient flow at depth.

I'd investigate mechanical causes before I spent dough looking for chemical ones. dF