Diver poisoned by carbon monoxide in scuba tank

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DiverDown
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Diver poisoned by carbon monoxide in scuba tank

Post by DiverDown » Wed Aug 09, 2006 5:58 pm

Who run barter town?

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diver-dad
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Post by diver-dad » Wed Aug 09, 2006 7:39 pm

Holy cow!! - The coroner's report says "the air in the cylinder contained seven times the "rapidly fatal" limit of carbon monoxide." :pale:

The guy never had a chance!
- DD

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DiverDown
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Post by DiverDown » Wed Aug 09, 2006 7:50 pm

Yeah and the sad thing is, that he would never have known his air was bad. But 7 times the rapidly fatal limit at the surface? Think about how much more at depth? Or mabey they already factored that in..
Who run barter town?

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Tom Nic
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Post by Tom Nic » Thu Aug 10, 2006 10:15 am

"The Coroner said the most likely explanation for the high levels of carbon monoxide was that it was "brought about by an idiosyncratic malfunction of the air compressing equipment"."

"Idiosyncratic malfunction?!?" ](*,) No disrespect to the lawyers on the board, but does that sound like legal doublespeak or what?!? Or maybe that's how they talk in New Zealand.

Does anyone have experience with air compressors and keeping them "healthy" that would care to comment on this? I know that compressors, filters, air quality, etc. are NOT all equal from dive shop to dive shop... I'd like to hear more.

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Post by JDR » Thu Aug 10, 2006 12:57 pm

Once again this is a cautionary note for all divers and especially those with their own compressors. If you have your own compressor, please conduct an air sampling test on it periodicially. If you get your air from an LDS please ask what their frequency of air testing is. If you get a tank which seems to have a bad taste or funny smell, don't use it.

One of the unfortunate issues here is the unanswered question "where did the airfill from? The shop he had a tank filled at 3 days before the incident has quarterly air tests done. This is a standard which PADI sets for it's 5 Star rated dive centers. This is a pretty good testing regime. Did the fill come from this diveshop or from some other air fill station?

How is it possible that something which went wrong with the compressor which affected only one air fill? Burning of oil within the compressor, sucking in exhaust from an internal combustion engine, etc? it also seems to indicate a cascade system of storage bottles was not used. The tank was likely filled directly from a compressor. If there was this level of CO contamination from a compressor hooked to a storage bank then it doesn't seem possible this could be an isolated incident.

Is anyone familiar with what frequency of air testing is recommended (or mandated) for the average PADI, or Naui, or TDI, IANTD, or SSI, or YMCA, etc, etc, diveshops?
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lamont
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Post by lamont » Thu Aug 10, 2006 2:49 pm

i don't know about CO-blow-by but i know that heat and humidity can cause oil and hydrocarbons to blow-by filters...

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CaptnJack
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Post by CaptnJack » Thu Aug 10, 2006 3:44 pm

Heat and oil can create CO, esp. from mineral oils and continuous blending. Synthetic oils are better in high O2 or just hot environments in general. Gasoline engine exhaust is the other major source.

The only thing which can remove CO is hopcalite (which actually catalytically converts it to CO2). Hopcalite is not required in compressor filters - shop or home. And it can't handle massive CO quantities as described in that accident report either.

Way better than infrequent, quarterly testing, which is is unlikely to capture transient CO spikes, is continuous monitoring of CO as is proposed here:
http://www.denninger.net/diving/co-analyzer.htm

A medical reg can be used to bleed off a few liters per minute and send that through an O2 analyzer (if continuous blending) and a CO detector.

The problem with quarterly air testing is that shops can do it right after an oil and filter change. Even the worst maintained compressors are likely to pass CGA grade E standards right after a filter change. Shops should be drawing samples 15 minutes earlier, right before a change is due.

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air testing

Post by Jeff Kruse » Thu Aug 10, 2006 4:37 pm

I agree with Captain Jack. Periodic air sampling does not tell you much. Constant monitoring and proper filter selection is better. I think you will find anyone willing to set up their own compressor will be more informed of these issues than the minimum wage temporary dive shop tank employee.

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CaptnJack
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Post by CaptnJack » Thu Aug 10, 2006 9:48 pm

I've got everything I need to CB now. Just have to plumb it all together. I trust my own gas and maintenance way more that any dive shop.

I KNOW when those filters were last changed (12.78 hours ago). They have just barely started to turn the 20% RH strip and I just submitted an air sample for testing about 0.5 hours ago. One with single filtered air, one through both the primary and secondary filter (I PP blend). If they both pass, I'll feel good about running filters to this point in the future.

I'll be changing the primary in another hour or so.

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thelawgoddess
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Post by thelawgoddess » Fri Aug 11, 2006 12:40 pm

wow; that is scary!!!
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rcontrera
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Post by rcontrera » Fri Aug 11, 2006 10:46 pm

There are electronic and mechanical CO monitors that can be installed on the outlet of air filters. They are well worth the money with their price ranging from less than $100 for a simple in line test eye to several thousand for the fancy electronic sensors. Either one would have given the fill station an indication of a problem. I am amazed an how few compressor operator will spend at least $100 for peace of mind.

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