Divers Killed by Carbon Monoxide Poisoning

[lord1234]

I would really suggest calling Larry...he will know this stuff.

 

[Dion]

As far as facts, within the rules of this Forum here are the facts that prompted my post and why I am going to purchase my own CO detector.

There is some speculation that a batch of tanks were CO contaminated (allegedly) recently at a resort during a fill by a faulty compressor. The contamination problem was detected. The tanks were placed aside, emptied, and then refilled with clean air. The diveboat was loaded with the new tanks. A resort diver decided to join the diveboat at the last minute for a scheduled two tank dive. Two additional tanks were loaded on the boat from the dock. The divemaster grabbed one of the newly loaded tanks for himself and the other was used by the late arriving diver. Unfortunately, both of the newly loaded tanks were from the "bad air" batch---the had never been emptied off. Divers entered the water 1st for a planned 80ft max depth type dive, followed by the divemaster. Within minutes the divemaster surfaced was helped aboard and experienced a cardiac arrest. Due the irreversible binding nature of CO to Hemoglobin, he was unable to be resuscitated. The dive group was summoned back aboard and found to be minus one diver. A quick search was mounted and they found the late arriving diver dead in the water. All the resorts boats were called back and diving was suspended for the subsequent day until the remaining tanks were checked and double checked. (All circumstances are under investigation.)

Where did you get this information? I would like to read more about it.

Thanks,

Dion

 

[DiveGolfSki]

...
There is some speculation that a batch of tanks were CO contaminated (allegedly) recently at a resort during a fill by a faulty compressor. The contamination problem was detected. The tanks were placed aside, emptied, and then refilled with clean air. The diveboat was loaded with the new tanks. A resort diver decided to join the diveboat at the last minute for a scheduled two tank dive. Two additional tanks were loaded on the boat from the dock. The divemaster grabbed one of the newly loaded tanks for himself and the other was used by the late arriving diver. Unfortunately, both of the newly loaded tanks were from the "bad air" batch---they had never been emptied (allegedly). Divers entered the water 1st for a planned 80ft max depth type dive, followed by the divemaster. Within minutes the divemaster surfaced was helped aboard and experienced a cardiac arrest. Due the irreversible binding nature of CO to Hemoglobin, he was unable to be ressusitated. The dive group was summoned back aboard and found to be minus one diver. A quick search was mounted and they found the late arriving diver dead in the water. All the resorts boats were called back and diving was suspended for the subsequent day intil the remaining tanks were checked and double checked. (All circumstances are under investigation.)

Do you have any links to the this incident?

As far as the procedures to detect and prevent this, anyone using Nitrox has to sign off that he/she has verified the mix using an oxygen sensor (I'll skip all the procedures and assume all nitrox rated divers know them). Would a similar system be effective for EAN 21 but expanded to include a CO sensor?

 

[pufferfish]

http://scubatoys.com/store/detail.asp?product_id=CoCop

Larry carries an item for CO detection....

This is a qualitative go/ no go type device which is one option however some of the early color changes can be difficult to discern. The first change will occur at 10 ppm and I think it goes completely black at 50 ppm. One should not dive the tank if any color change is seen. This is the range of colors on the element.
http://lawrence-factor.com/lp604053oo.htm

There is a video here of how to use the device. You might check how long one must flow the device to ascertain the lower concentrations are not present.
http://www.co-cop.com/

The only electrochemical device I have seen dedicated to scuba is this one. The issue with these devices is the expense, short sensor life (12 to 18 months), and assuring proper calibration. You will have to buy a small tank of CO for calibration.
http://www.amronintl.com/diving/products.cfm?id=1265
http://www.nuvair.com/shopsite_sc/store/html/analyzers_proco.shtml

For the fill station this is the device Bauer offers on its compressors as an option. I think the price is in the $2000 range and again it requires frequent calibration.
http://www.nyad.com/Series_500.html

CO is tasteless, odorless, irritantless, and colorless so yes one requires some sort of device to detect its presence.

 

[fdog]

From the CDC:

The median effective concentrations to produce incapacitation (EC50s) in rats have been determined to be 2,667 ppm and 1,450 ppm in 15 and 30 minutes, respectively [Hartzell et al. 1985].

Simple math shows that 360 ppm would be a bad thing for a recreational dive at depths to 90-100 fsw, and 200 ppm would be bad for a technical dive at 200 fsw.

The LC50 (half the subjects will die at this concentration) lies at 5207 ppm for 30 minutes. This would equate to a 1300 ppm concentration for a diver at 100fsw.

Of course, these are extrapolations from surface data. Pressure may well exhibit synergistic effects that make a CO exposure at depth worse.

The TLV (permissable workday exposure) is 25 ppm, above which an increase in cardiovascular problems has been noted. This would equate to 6 ppm for a 100 fsw dive.

As a side note, we see 6 to 8 ppm concentrations in ambient air here during the winter months under an inversion layer. Gasoline-powered engines easily produce 500+ ppm in their exhaust. And, hot compressors are believed to generate significant amounts of CO from cracking of the synthetic oil.

Filtration is the last line of defense here; I for one would buy a combined O2/CO monitor built for the rigors of diving.

All the best, James

 

[fdog]

I'd add that we've passed up diving in great locations because the dive op had shoddy filter stacks.

All the best, James

 

[BigJetDriver]

All posters are reminded that this discussion is about CO contamination in divers' breathing air, physiological effects of such an event, and ways to avoid same.

Any reference to a specific event has been removed, will continue to be removed, and it is requested that posters restrain themselves in this respect.

 

[hermosadive]

Any reference to a specific event has been removed, will continue to be removed, and it is requested that posters restrain themselves in this respect.

Why? If someone quotes/posts public information why would you feel the need to censor that information? MBA programs use case studies to further education, don't you think the same logic can be applied here?

 

[Uncle Pug]

From my sticky post at the top of this forum:
(1) Events will be "scrubbed" of names. You may refer to articles or news releases already in the public domain, but the only name you may use in this forum is your own.
(2) No "blamestorming." Accident analysis does not "find fault" - it finds hazards - and how to reduce or eliminate them.
(3) No flaming, name calling or otherwise attacking other posters. You may attack ideas; you may not attack people.
(4) No trolling.
(5) Remember that you cannot read minds. Restrict comments to what happened and how to prevent it, without speculating on what someone else was thinking (or not). The only thoughts you are qualified to share are your own.

 

[do it easy]

http://www.oxycheq.com/Oxygen_Analyzer_Main_Page.html

If you want to be really slick, get yourself a water tight case with a O2, He, and CO all inline so that you can sample eveything at once. And don't forget the smell test.