PDA

View Full Version : Carbon Monoxide Question.



BigDon
2015-Jul-21, 09:15 PM
As far as non-disruptive instant deaths I read about a submarine accident where several engineers tried to cross a room that was too far for their plugged in air lines.

Each would hyperventilate, hold their breathe, take the helmets off and then immediately die. They didn't know or maybe didn't care that they were in an 80% carbon monoxide atmosphere under 11 atmospheres of pressure.

With the exception of some deep bone cells wouldn't that environment saturate and kill every single cell in your body instantly?

John Mendenhall
2015-Jul-22, 02:08 PM
Wow. Got a link to the story?

I am aware of the unventilated closed compartment no no, but this one is a dandy.

profloater
2015-Jul-22, 03:01 PM
i do not understand why co would get you without breathing it, did they start out at a different pressure in their suits?

Jeff Root
2015-Jul-22, 08:35 PM
I'm guessing that the CO at 11 atmospheres pressure infuses
the skin, so it can kill without having to be breathed. It wouldn't
kill instantly, but it might incapacitate instantly, and then take
only a minute to kill.

So I'm further guessing that these guys were being supplied
with a mixture of oxygen and helium or the like at the same
11 atmosphere pressure as the ambient carbon monoxide.

Were they trying to escape by crossing the room? Or what?

-- Jeff, in Minneapolis

BigDon
2015-Jul-23, 03:29 PM
i do not understand why co would get you without breathing it, did they start out at a different pressure in their suits?

Under that much pressure it entered through the eyes and mucus membranes is what I was told.

It was when the Kursk went down. As to what they were trying to do, I can't tell you why people go into submarines in the first place, much less why they do what they do.

grant hutchison
2015-Jul-23, 05:00 PM
It was when the Kursk went down.Interesting story. A note found in the Kursk, evidence of a fire, and the post mortem report all suggest that the crew were exposed to carbon monoxide and hypoxia, which led to their deaths.
They also reported feeling their ears pop, indicating that water was entering the pressure hull somewhere and driving the ambient air pressure higher, and I've read suggestions that they might have developed nitrogen narcosis as a result.
So: high pressure, tick; carbon monoxide, tick. But that's a long way from this story!

I so far can't find any reports of mucosal or cutaneous absorption of carbon monoxide leading to poisoning, though the situation described is ... ahem ... unusual. But that should really have made it more likely that such a remarkable event would crop up in the various gas safety manuals I've checked.
Puzzled.

Grant Hutchison

John Mendenhall
2015-Jul-23, 10:17 PM
If we assume they went from around one atmosphere to 11 atmospheres how about punctured eardrums as an admittance route for the CO?

Ouch what a. painful thought!

grant hutchison
2015-Jul-23, 10:55 PM
If we assume they went from around one atmosphere to 11 atmospheres how about punctured eardrums as an admittance route for the CO?Might be tricky getting your helmet off, with a ten-atmosphere pressure gradient holding it on ...

I've thought about this for a while, and I just don't believe gas can diffuse into tissues that fast, either through skin or mucous membranes, even under a large pressure gradient.
The "experiment" has been done in reverse, with accidental decompression of divers. Now, nitrogen has about the same water solubility as carbon monoxide. If it could diffuse almost instantaneously along a pressure gradient, just blowing straight out of someone's eyeballs and oral mucosa, then there wouldn't be such a problem with tissue bubble formation and the bends. Survivors of decompression incidents would instead routinely report their eyelids flapping in the breeze as large volumes of nitrogen blew out of their eyeballs.

Grant Hutchison

cjameshuff
2015-Jul-23, 10:56 PM
How would a compartment end up filled with 80% carbon monoxide? There's nowhere near enough oxygen in the air to make that much carbon monoxide, and a fire would produce large amounts of other gases and probably extinguish with a fair amount of oxygen left. CO is used in some industrial processes, but on a submarine?

Carbon monoxide kills by irreversibly binding to hemoglobin, you suffocate because your blood loses its ability to absorb oxygen. Not an instant death, and if they were holding their breath, their blood wasn't absorbing any oxygen anyway. They might possibly absorb a lethal amount in a short period from such a high concentration at that pressure (the skin is not a good gas exchange membrane, but it doesn't take very much CO), but I doubt it'd be any faster than suffocating.

schlaugh
2015-Jul-23, 11:41 PM
The CO was apparently produced when an oxygen canister ignited oil floating in the compartment. From the Wikipedia article:


The official investigation into the disaster discovered that a number of potassium superoxide chemical cartridges, used to absorb carbon dioxide and chemically release oxygen to enable survival, were found in the ninth compartment. But the level of carbon-monoxide in the compartment exceeded what people can produce in a closed space.[6] Divers had found ash and dust inside the compartment when they first opened that hatch, showing evidence of a fire. But this fire was separate from that caused by the exploding torpedo. This and other evidence found in the salvaged wreck suggested that while the crew survived for a period of time, they may have accidentally dropped one of the chemical superoxide cartridges into the seawater slowly filling the compartment. When the cartridge came in contact with the oily sea water, it triggered a chemical reaction and flash fire.[27] The investigation showed that some men temporarily survived this fire by plunging under water, as fire marks on the bulkheads indicated the water was at waist level at the time. But the fire consumed all remaining oxygen, killing the remaining survivors,[56] who died of asphyxiation or carbon monoxide poisoning.[27]

grant hutchison
2015-Jul-24, 11:09 AM
The CO was apparently produced when an oxygen canister ignited oil floating in the compartment. From the Wikipedia article:But what we're being told is that there were in excess of eight atmospheres pressure of carbon monoxide in this compartment. That's a lot of incomplete combustion, implying a lot of oxygen and fuel. And what happened to the nitrogen in the air? We'd need to invoke a continuous flow of high-pressure oxygen into this compartment, at just the right rate to maintain a massive episode of incomplete combustion.
It's all very odd.

Grant Hutchison

Jens
2015-Jul-24, 12:47 PM
In the case of the Kursk, it's also important to remember that nobody was narrating this as it happened. The water level was surmised from the burn marks, the cause of death was surmised from the autopsies. It's not like there was a security camera watching what was going on. It took about ten days to get into the submarine.

BigDon
2015-Jul-24, 04:05 PM
Their torpedoes were powered by high test peroxide, if that's a clue Dr. Grant.

From Wiki


Finally pushing aside the Navy's long-standing blame on a collision with a foreign vessel, a report issued by the government attributed the disaster to a torpedo explosion caused when high-test peroxide (HTP), a form of highly concentrated hydrogen peroxide, leaked from a faulty weld in the torpedo's casing.[3][10][23] The report found that the initial explosion destroyed the torpedo room compartment and killed everyone in the first compartment.[24][25] The blast entered the second and perhaps the third and fourth compartments through an air conditioning vent. All of the 36 men in the command post located in the second compartment were immediately incapacitated by the blast wave and possibly killed.[26] The first explosion caused a fire that raised the temperature of the compartment to more than 2,700 C (4,890 F).[27] The heat triggered the warheads of between five to seven additional torpedoes to detonate, creating an explosion equivalent to 2-3 tons of TNT[28] that was measured 4.2 on the Richter scale on seismographs across Europe[29] and was detected as far away as Alaska.[30]