I'm not sure WHERE to ask this, but, how does a wet cloth
work in an airplane crash anyway?
In step 3 at 45 seconds into this video shows it in use:
I agree with BobF; the wet cloth acts like a filter for both smoke
particles and fumes that would be soluble in water.
During World War One, Canadian soldiers being attacked with chlorine gas
(called "Mustard Gas" at the time because of it's yellow-green colour)
were told to urinate into their handkerchiefs and to breathe through
that wet cloth. The chlorine gas would dissolve in the water as it
passed through the handkerchief, thereby keeping our troops safe and
That nicely summarized FAA article explains:
- Smoke is a complex of particulate matter, invisible combustion gases & vapors suspended in the fire atmosphere.
- Inhalation of toxic gases in smoke is the primary cause of fatalities
- Carbon monoxide & hydrogen cyanide are the principal toxic combustion gases
- Carbon monoxide combines with the hemoglobin in blood and interferes with the oxygen supply to tissues
- Hydrogen cyanide inhibits oxygen utilization at the cellular level.
- Carbon dioxide is a relatively innocuous fire gas, increases respiration rate causing an increase in the uptake of other combustion gases
- Irritant gases, such as hydrogen chloride and acrolein, are generated from burning wire insulation
- Generally, carbon dioxide levels increase while oxygen concentrations decrease during fires.
And then finally, the article suggests:
- Cloth held over the nose and mouth will provide protection from smoke particulates;
- If the cloth is wet, it will also absorb most of the water-soluble gases (i.e., hydrogen cyanide & hydrogen chloride).
What's interesting is that the entire article doesn't discuss any dangers
of breathing smoke particulates, so, why it bothers to mention a dry cloth
is perplexing since we can safely assume that filtering out particulates is
merely a convenience, and not a safety issue.
So, now we're left with the a WET cloth absorbing water-soluble gases.
Of the two water-soluble gases, only hydrogen cyanide was listed in
the article as being a safety issue (the other water-soluble gas was
merely an irritant).
So, I guess we finally have the answer to "why the wet cloth?".
The WET CLOTH filters out (water soluble) hydrogen cyanide:
"Hydrogen cyanide poisoning signs & symptoms are weakness, dizziness, headache,
nausea, vomiting, coma, convulsions, & death. Death results from respiratory arrest.
Hydrogen cyanide gas acts rapidly. Symptoms & death can both occur quickly."
You should know that inhaling that will kill you.
And at high temperatures, the vapors can be lethal,
also. And you want people to carry it on PLANES!
For safety, all passengers should fly nude. Discounts
offered to cheerleaders squads who get frequent flier
On Tuesday, May 20, 2014 12:52:29 PM UTC-4, Higgs Boson wrote:
Yes they do. You can carry on as much water as you want,
as long as you either buy it or fill the bottle at a drinking
fountain after the TSA checkpoint. You could also carry 3.4 oz
through TSA, which is pretty close to the stated 4 ounces. It's
also not unusual for there to be a a bottle or two of airline
water somewhere around you, many airlines hand them out during
Not that any of that matter much in the grand scheme of things.
On Fri, 16 May 2014 03:30:48 +0000, Ann Marie Brest wrote:
Armed with the new keywords "wet cloth hydrogen cyanide", I find more
on the toxicity of HCN over here:
"Hydrogen cyanide is readily absorbed from the lungs; symptoms of poisoning
begin within seconds to minutes. The odor of hydrogen cyanide is detectable
at 2-10 ppm (OSHA PEL = 10 ppm), but does not provide adequate warning of
hazardous concentrations. Perception of the odor is a genetic trait
(20% to 40% of the general population cannot detect hydrogen cyanide);
also, rapid olfactory fatigue can occur. Hydrogen cyanide is lighter than air.
Children exposed to the same levels of hydrogen cyanide as adults may
receive larger doses because they have greater lung surface area:body
weight ratios and increased minute volumes:weight ratios."
"Hydrogen cyanide acts as a cellular asphyxiant.
By binding to mitochondrial cytochrome oxidase, it prevents the utilization
of oxygen in cellular metabolism. The CNS and myocardium are particularly
sensitive to the toxic effects of cyanide."
"In the United States, antidotes for cyanide include amyl nitrite perles
and intravenous infusions of sodium nitrite and sodium thiosulfate,
which are packaged in the cyanide antidote kit."
But, what we need to know is how effective is the wet cloth in reducing
the hydrogen cyanide gases in the cabin air.
On Fri, 16 May 2014 03:41:06 +0000, Ann Marie Brest wrote:
And, here's what OSHA has to say about the dangers of HCN:
"[Hydrogen cyanide] is capable of bringing to a halt all
"A few inhalations of high concentrations of HCN may be
followed by almost instantaneous collapse and cessation
"270ppm HCN is immediately fatal to humans"
"181ppm HCN is fatal after 10 minutes"
"135ppm HCN is fatal after 30 minutes"
"110ppm HCN is fatal after 60 minutes"
"Humans tolerate 45ppm to 54ppm for 1/2 to 1 hour without
immediate or delayed effects, while 18ppm to 36ppm may
result in symptoms after exposure for several hours."
So, the key question is what the HCN concentrations are in
a typical airplane cabin fire?
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