Three dead and one in recompression chamber in Italy, Tuscany

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Now all the main news outlet are catching up with the carbon monoxide presence in lethal quantities.
This is the preliminary outcome of the analysis of the tanks content and the autopsies.
Final reports of the autopsies are expected on Friday.
The analysis on the tanks were done with the presence of the lawyer of the Diving therefore it will be valid as evidence at trial.

Fabio

Sub morti alle Formiche: «Nelle bombole ci sono tracce di monossido di carbonio» - Corriere Fiorentino
Sub morti, monossido in bombole e sangue - Toscana - ANSA.it
Sub morti a Grosseto: l?autopsia rivela tracce di monossido di carbonio nel loro sangue | UrbanPost
La Stampa - Sub morti alle isole Formiche, trovate tracce di monossido di carbonio nelle bombole e nel sangue
Sub morti, ''monossido di carbonio nelle bombole e nel sangue'' - Adnkronos
 
Sorry guys, but there is just no way you can detect CO with an O2 analyser (and won't go in the technicalities).

Lesson learnt here is that those who sell gas should test it with a CO analyser before releasing it to the end-user.

It would be prudent for the end-user to test the tanks as well with a CO analyser (since it is not done as a matter of course by Dive Shops and in any event why trust the Dive Shop with your own life???).

Two suppliers:

EII CO Carbon Monoxide Analyzer: Analox - Looking after the air you breathe.

http://www.temc.it/en/diving/de-ox-safe-carbon-monoxide-analyzer
Yep, and Analox and other companies have great inline CO monitors that can be set to auto shut off, but you can't trust supplier in general. The largest fill station in Coz was given a free Analox inline system for free, but still was caught supplying CO tainted air. They could get more tanks filled if they ignored the alarms and disabled the auto shut off. I was really disappointed that DAN America's only significant action was to give away more systems. :mad:

Here is another good unit available in the States for half of what other cost...
Cabon Monoxide Scuba Tank Analyzer Out of stock for now, but you can talk to them. I have with the sales manager, Kevin. I've been wearing the basic unit out and about to see how common cross reactions may be, etc.

Could we? Not trying to sharpshoot you, but I think you overlooked something. With the CO aren't we looking at something like parts per million, so even a high concentration , say 100 PPM maps to a very tiny fraction of the overall percentage. I'm not familiar with the O2 testers used, but from what I've seen, it looks like they, at most, read to 1 or maybe 2 decimal points. 100 PPM should work out to 0.001%. (and I may have 1 too few "0"s).

I'm not sure that we could pick up the CO content unless it was so high that it would be a significant portion of the gas, say 2-3%.

If I'm wrong, please let me know, like I said, not trying to sharpshoot you, just doesn't compute in my brain.

Steve
10,000 ppm = 1%. Checking O2 will not tell you anything about CO risks. Getting portable CO units that can check in the single digits ppm at affordable prices, many of them water & drop resistant, is a remarkable accomplishment - that we should use!

OK. From a chemistry perspective - CO and O2 won't mix, is that correct? So you can have 32% O2 in a tank and also some CO ?

I guess my confusion stems from a lack of understanding of this.

P
No, they'll blend easy. You have done the Nitrox course have you?

This is now becoming a tech diving/gas blending thread, but given the outcome of the incident I feel it appropriate. Even because you do not need to be tech diving to have benefit from understanding gases and how they interact with your body.

I am in Europe and I will be referring to BS EN12021 which is the standard for breathable air which says that breathable air should not contain more than 15 ppm of CO.

I can already hear DandyDon scream out loud "too much" and he is right. I will explain why.
I thought that most of Europe had changed to 5ppm, or 3 max...?

Another major risk is once CO binds to your blood at 3 to 6 atmosphers, it hits you harder when you ascend as the PPO drops but the CO remains in your blood blocking O2 movement.

I will join DandyDon Crusade :) DAN Europe is now carrying a CO analyser in their shop (available from Sep 14).

Fabio
Great, which one? How much?

I cannot see any reason for accepting any CO in SCUBA gases as an end-user.

It just should not be there.

If you get any, buy your gas elsewhere.
Correct. If you find 1 or 2 ppm, it could be an error or handling mistake, but 3 and above - you got to wonder what else is getting in the tanks?
 
Another major risk is once CO binds to your blood at 3 to 6 atmosphers, it hits you harder when you ascend as the PPO drops but the CO remains in your blood blocking O2 movement.

This may be just another way of saying what you meant by this...

Oxygen is primarily carried through the body by hemoglobin. CO connects to hemoglobin and thus interferes with the blood's ability to carry oxygen. At greater depths and thus greater partial pressure of oxygen, the blood plasma will carry more oxygen, thus giving the blood an additional ability to carry oxygen to the tissues and partially making up for the interference of the CO. As the partial pressure of oxygen drops, the ability of plasma to carry oxygen decreases, and the CO contamination becomes more problematic.
 
In Reply to your post [post=7202563]#7202563[/post]
This is now becoming a tech diving/gas blending thread, but given the outcome of the incident I feel it appropriate. Even because you do not need to be tech diving to have benefit from understanding gases and how they interact with your body.

I am in Europe and I will be referring to BS EN12021 which is the standard for breathable air which says that breathable air should not contain more than 15 ppm of CO.

I can already hear DandyDon scream out loud "too much" and he is right. I will explain why.
I thought that most of Europe had changed to 5ppm, or 3 max...?

Another major risk is once CO binds to your blood at 3 to 6 atmosphers, it hits you harder when you ascend as the PPO drops but the CO remains in your blood blocking O2 movement.
Unfortunately the reference standard is 15 ppm ... but most of the time I read 0 ... sometime 1, somebody says it becomes boring :)

I will join DandyDon Crusade :) DAN Europe is now carrying a CO analyser in their shop (available from Sep 14).

Fabio
Great, which one? How much?
http://www.temc.it/en/diving/de-ox-safe-carbon-monoxide-analyzer
About 250 Euros for members 50 more for non-members

I cannot see any reason for accepting any CO in SCUBA gases as an end-user.

It just should not be there.

If you get any, buy your gas elsewhere.
Correct. If you find 1 or 2 ppm, it could be an error or handling mistake, but 3 and above - you got to wonder what else is getting in the tanks?

Agreed!

Fabio
 
This may be just another way of saying what you meant by this...

Oxygen is primarily carried through the body by hemoglobin. CO connects to hemoglobin and thus interferes with the blood's ability to carry oxygen. At greater depths and thus greater partial pressure of oxygen, the blood plasma will carry more oxygen, thus giving the blood an additional ability to carry oxygen to the tissues and partially making up for the interference of the CO. As the partial pressure of oxygen drops, the ability of plasma to carry oxygen decreases, and the CO contamination becomes more problematic.
Yes, better stated - except for one glaring mistake: blood plasma does not carry oxygen; as stated at first there, hemoglobin carries oxygen. Plasma carries carbon dioxide, among other things.
 
Yes, better stated - except for one glaring mistake: blood plasma does not carry oxygen; as stated at first there, hemoglobin carries oxygen. Plasma carries carbon dioxide, among other things.
Nope. It will carry it at high partial pressures. It is not immune to Henry's Law.
 
Yes, better stated - except for one glaring mistake: blood plasma does not carry oxygen; as stated at first there, hemoglobin carries oxygen. Plasma carries carbon dioxide, among other things.
DD,
Plasma as all liquids has capability to carry dissolved gases. In fact at 0.16 bar haemoglobin is completely saturated and from that point on increase of ppO2 will increase the amount of O2 in the liquid phase of blood (plasma).

At 1.6 bar ppO2 almost no haemoglobin carried oxygen is used by tissues. This is why hyperbaric oxygen is the therapy for CO intoxication. You have your tissues oxygen requirement supplied by the plasma even if all haemoglobin is tied to CO.

Fabio
 
Well this tragedy will hopefully save others by bringing CO poisoning while scuba diving to the forefront.

Since I have first hand experience with CO in our tanks, I can say diving nitrox has an advantage in that it is checked before diving it. The dive boat we were on was putting in close to 38% and getting 32% out. Turns out the filters were burning up, and although I did not own a CO meter at the time, I promptly became the owner of one. So I have no idea how much CO was present, but 14 people on board had symptoms of CO poisoning. We had numerous O2 meters on board, but it was the boat crew that shut everything down and ended the trip early. They had been on the phone with Rix trying to find a solution and the solution was a rebuild.
 
Ok, I stand corrected on blood plasma carrying Oxygen, thanks.
Well this tragedy will hopefully save others by bringing CO poisoning while scuba diving to the forefront.

Since I have first hand experience with CO in our tanks, I can say diving nitrox has an advantage in that it is checked before diving it. The dive boat we were on was putting in close to 38% and getting 32% out. Turns out the filters were burning up, and although I did not own a CO meter at the time, I promptly became the owner of one. So I have no idea how much CO was present, but 14 people on board had symptoms of CO poisoning. We had numerous O2 meters on board, but it was the boat crew that shut everything down and ended the trip early. They had been on the phone with Rix trying to find a solution and the solution was a rebuild.
I hope more start owning, carrying, and checking. So many professionals are still stubbornly not supporting the needed actions.

But then there are still homes in America without Smoke Alarms and most don't have CO Alarms, and they are so cheap! I like one in every bedroom, plus living areas.
 
No, they'll blend easy. You have done the Nitrox course have you?

Yes. TDI.

The following explains the origin of CO and goes some way towards satisfying my puzzlement
Carbon monoxide is produced from the partial oxidation of carbon-containing compounds; it forms when there is not enough oxygen to produce carbon dioxide (CO2)
I needed a reminder that it won't react and transform into some other gas... even with a higher pp of oxygen
 
https://www.shearwater.com/products/peregrine/

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