Carbon monoxide discussion - split from Fiona Sharp death in Bonaire thread

[homerdoc]

From the Bonaire Reporter

 

[Wookie]

Carbon Monoxide? Who did her fills, Buddy Dive?

 

[chillyinCanada]

And why didn't it affect her earlier in the dive?

 

[wgw04024]

Is the carbon monoxide comment a fact, or just something they 'threw out there'?

 

[DandyDon]

And why didn't it affect her earlier in the dive?

Ok, well, even a small amount of carbon monoxide CO can be toxic, having an increasing buildup in the blood at greater depth, then and increasingly toxic effect on ascent as the PPO drops while the PPCO remains bound for a greater time. That is possible, but no information was offered to support that claim.

I have no understanding about rebreathers and can only wonder why this was stated...

I wonder if the examining agent had a calibrated CO tester for whatever gases were used, or the physician doing the autopsy had a blood CO tester?

And we know that this is untrue...

As it does not include the medical triggers.

 

[tursiops]

That’s a really bad error to make.

But not at all surprising. In the media, all our tanks are oxygen cylinders and 1m=3ft.

 

[DandyDon]

So many confuse CO2 and CO, carbon dioxide and carbon monoxide, that I have to wonder if many have no understanding of the differences, or just confuse the words. I enjoyed high school chemistry but I don't remember many opting for it.

On a related note, it's time to test home CO alarms and change the batteries in the southern US, overdue in the north. It kills every week in homes too thru the winter.

 

[Dan]

Ya, human tolerance to carbon monoxide (CO) and carbon dioxide (CO2) are way way different. Human Time-Weighted Average (TWA) for CO is 35 ppm, CDC - Immediately Dangerous to Life or Health Concentrations (IDLH): Carbon monoxide - NIOSH Publications and Products and for CO2 is 5000 ppm, CDC - NIOSH 1988 OSHA PEL Project Documentation: List by Chemical Name: CARBON DIOXIDE

NIOSH throws a lot of exposure limit numbers in the papers above. Here are some definitions of what they mean: Permissible exposure limit - Wikipedia

We breathe out CO2, not CO. The CO poisoning is usually from bad air in the tank during filling up the tank. Sometimes the air compressor generator exhaust may be too close to the air intake into the air compressor and it ends up sucking some of the generator exhaust that may have elevated CO from incomplete combustion of the fuel used to run the generator. If that is the case, there would be more than 1 diver that would get CO poisoning in Buddy Dive, ranging from headache to passing out.

 

[DandyDon]

We breathe out CO2, not CO.

Actually, we breathe out a little CO, enough to test a CO tank tester. I guess you don't have one? Someday we may discover a benefit to very small amounts.

The CO poisoning is usually from bad air in the tank during filling up the tank.

For divers, yes - aside from boat exposure, especially with the station wagon effect. But she was on a rebreather so I don't see a possible exposure?

Sometime the compressor generator exhaust may be too close to the air intake into the compressor and it ends up sucking some of the generator exhaust that may have elevated CO from incomplete combustion of the fuel used to run the generator.

Sometimes, altho intake of CO mixed with good air is less likely to be as big of a risk as a overheated compressor with old filter creating it internally.

If that is the case, there would be more than 1 diver that would get CO poisoning in Budy Dive, ranging from headache to passing out.

A common myth that has been disproved many times. But there is no information to support the claim here. I think sloppy news writing lead to that confusion.

 

[Dan]

Actually, we breathe out a little CO, enough to test a CO tank tester. I guess you don't have one? Someday we may discover a benefit to very small amounts..

You are right about that. What CO concentration do you measure from your breath? I'm guessing about 1-5 ppm? However the majority of the gas coming out of your breath would be N2, O2, H2O & CO2, Breathing - Wikipedia Those gases are in percentage level vs ppm level of CO, which is 10,000 times less than the majority of the exhale gases.