How does a wet cloth really help (scientifically) to survive an airplane crash?

On Fri, 16 May 2014 07:48:32 -0400, micky wrote:

It is frequenty reported that someone dies of smoke inhalation. That's
certainly something to care about.

Looking up what "smoke inhalation" means, I find it's a catch-all
phrase, sort of like "germ" or "headache" or "homicide" or "drugs".

In and of itself, it tells us little of the actual cause of death,
according to information in this Firefighter document all about SMOKE:
http://www.pbfeducation.org/files/TH...Supplement.pdf

"Typically, when someone dies in a fire, it’s attributed to
the nebulous cause of “smoke inhalation.� In truth, it’s more
complicated than that."

"[the] potential cause of death in smoke inhalation victims -
[is] cyanide poisoning."

On Fri, 16 May 2014 08:09:03 -0700, RobertMacy wrote:

I also heard that in the field urinate upon a 'dirty' wound to wash it,
because urine is more sanitary than all that muck in there.

Voided urine is sterile unless you have a urinary tract infection,
but, given the excretionary purpose of the kidneys, I'd look up
the composition, just in case salt isn't a major component.

As for what "smoke inhalation" really means, it seems that this
short summary indicates the twin dangers of so-called "smoke inhalation",
only one of which a wet cloth will help ameliorate:
http://www.firesmoke.org/wp-content/...ng-Outline.pdf

Toxic Twins of Smoke Inhalation
i. Cyanide
– Mechanism of Action - Cyanide Kills Organs
ii. Carbon Monoxide
– Mechanism of Action - CO Kills the Blood

On 2014-05-16, Ann Marie Brest wrote:
On Fri, 16 May 2014 04:00:28 +0000, Ann Marie Brest wrote:

I'm pretty surprised about those findings, but they in this article
specifically about guarding your airway during an airplane cabin fire.

This Airbus briefing discusses HOW to use the wet towels properly:
http://airbus.com/fileadmin/media_ga..._OPS-SEQ06.pdf

"Use wet towels, a wet cloth, or a head rest cover to reduce some of
the effects of smoke inhalation. Instruct passengers to hold the wet
towel/cloth over their noses and mouth and breathe through it."
.
This onboard emergency description mentions not to use ALCOHOL:
http://www.casa.gov.au/wcmswr/_asset...r/apr_fire.pdf

"To limit the effects of toxic fumes, a wet cloth should be
placed over your nose and mouth (a headrest cover or any other
available fabric is suitable). Use water, soft drink or other
non-alcoholic beverages to moisten the fabric."

Given that alcoholic drinks are almost all water anyway, I wonder
why they bothered to mention non-alcoholic drinks?

you wouldn't want to wet it with vodka, or whiskey and have it catch fire.

Does alcohol on the wet fabric do anything different with HCN?

A quick searh found no reactions ot HCN with dilute or concentrated
alchols. I think it's mainly the fire risk.


--
umop apisdn


--- news://freenews.netfront.net/ - complaints: ---

On 2014-05-16, micky wrote:
I'm pretty sure the amount of cyanide varies widely from one airplane
fire to another, but there is no time to measure it.

as I understand it the HCN is produced when plastics containing
nitrogen burn in an oxygen poor environment. Stuff like synthetic
rubber upholstery, pulyurethane foam insulation and and melamine
tray-tables

--
umop apisdn


--- news://freenews.netfront.net/ - complaints: ---

I'm pretty sure the amount of cyanide varies widely from one airplane
fire to another, but there is no time to measure it.

as I understand it the HCN is produced when plastics containing
nitrogen burn in an oxygen poor environment. Stuff like synthetic
rubber upholstery, pulyurethane foam insulation and and melamine
tray-tables

As I understand it, this is akin to the major reason you're supposed
to get out of a computer room if the Halon extinguishers are
triggered. The Halon itself isn't particularly hazardous (at the
concentrations used in these systems), but the combustion byproducts
from burning plastics and etc. are really nasty. The Halon suppresses
some of the flame reactions and stops the fire, but it doesn't get rid
of the poisonous partially-combusted plastics and other decomposed
flammables.

On Fri, 16 May 2014 10:54:50 -0700, Ann Marie Brest
wrote:


So, we can safetly assume that a wet cloth does trap particles,
but, nobody has reported any real evidence that "smoke inhalation"
(presumably that means particulate inhalation) is either immediately
dangerous,

What do I care if it's not immediately dangerous if it's dangerous
later. I inhale smoke and I don't die in 5 minutes, but I'm sick 20
minutes later, or 2 days later, and I die 3 days later, or I'm sickly
for the rest of my life These are all bad.

I just learned a couple days ago that my brother's aunt died of
mesothelioma, a cancer associated with exposure to asbestos,

She wasn't a steam fitter. She worked in an office. At the age of 30
she moved 20 miles downwind from a steel company, and it didn't kill her
immediately, but it still killed her. Why do you think all that
matters is if something is *immediately* dangerous?





or the *reason* for the wet cloth.

Based on the evidence repoted to date, the reason for the wet rag
seems to be to trap water soluble gases, of which HCN is the most
dangerous in a cabin fire (according to all the references).

On Fri, 16 May 2014 10:50:13 -0700, Ann Marie Brest
wrote:

On Fri, 16 May 2014 07:48:32 -0400, micky wrote:

It is frequenty reported that someone dies of smoke inhalation.

It's frequently reported that people die of heartbreak also.

Give me a break. Now you're using nonsense to try to refute facts.

If you google smoke inhalation, you likely may read that the US
ambassador to Libya who died in the fire at the consulate in Bengazi,
Ambassador Stevens, did not die from burns but from smoke inhalation.
Do you think he really died of a broken heart, or that they just called
it smoke inhalation to mess up this thead for you?

And that Vikings wore horns on their helmets.
And that Moses parted the water of the Red Sea.
Or that George Washington had wooden teeth.
Or that Benjamin Franklin publicly proposed the wild turkey be
used (instead of the bald eagle) as the symbol of the US.
Or that Napoleon Bonaparte was shorter than the average
Frenchman of his time.
etc.

Lots of things are "frequently reported" and just as frequently
untrue. That's why I had asked for "scientific" answers.

Anyone can guess wrong.

No one's guessing, lady, except you.

You've lost this argument. Give it up. No matter what you might yet
successfullly show about fire deaths, you lost when you said that we
(meanig you) could safely assume something just because the opposite was
not written in a short article. You have to abandon that method of
thinking, or at least not bring it up here, and then you might have your
future posts taken more seriously.

On Sat, 17 May 2014 08:20:24 +1200, george152 wrote:

On 17/05/14 05:01, wrote:

Something to keep the father occupied and out of the way.


Bingo

I've certainly thought about that.

"Ann Marie Brest" wrote in message ...
On Thu, 15 May 2014 20:16:19 -0400, Frank wrote:

What's the wet cloth (scientifically) doing?
http://www.faa.gov/pilots/safety/pil.../Smoke_Web.pdf

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.

Logically, breathing through a wet cloth would also remove more particulate matter than through a dry cloth. Try blowing cigarette smoke thru a dry handkerchief and a wet one and you'll see a big difference.

On Fri, 16 May 2014 10:34:21 -0700, Ann Marie Brest
wrote:

On Fri, 16 May 2014 08:05:39 -0700, RobertMacy wrote:

Was there any mention of the radiated heat from these fires?

Yes.

We noted that this flight safety PDF, which was all about
protecting your airways in a cabin fire, explicitly said
that the dry heat of a cabin fire isn't a major concern
when it comes to protecting your breathing airways:
http://flightsafety.org/download_fil...t06_p28-30.pdf

As already noted, they said, verbatim:
"the human body’s upper airway naturally provides significant
protection to the lower airway and lungs against extreme
heat from hot, dry air."

Absolutely none of the air-safety PDFs yet mentioned *anything*
about the wet cloth having anything to do with cooling hot
air, so, we can safely assume the only *safety* purpose of

Your career is not in science, is it? Neither is mine, but I still know
we can't safely assume things like this from the absence of mentioning
cooling hot air. There are other good reasons but the simplest is
that the pdf files might be crap. There is plenty of crap on the web,
and even peer reviewed journals occasionally publish crap.

Here's an extreme case, but other circumstances yield similar resutls.
My roommate was a biology PhD candidate doing research in a foreign
county. A bunch of grad students all stayed at the same rural room &
board place and did there research in the jungle that surrounded them.
One of them would stop by where someone else was working and he'd chat.
Embedded in the conversation was "What experiement are you doing? What
kind of results are you getting?" And then he'd go back to his room and
write a journal article, send it to a journal, and because his writing
style was good, clear etc. it often got published.

Other times, he didn't go out of his room. He just sat back and asked
himself, What would a good experiement be? And what kind of results
might I get? And then he'd write an article based on those two
things.

He was published in every peer-reviewed journal in his field (and
non-peer-reviewed if there were such things then).

It was only after his artcles appeared that sometimes people would write
in, "I did that experiment and my results were nolthing like his." But
before many people were aware of his habits he had his PhD and no one
could take it away. Eventually he was drummed out of any faculty job
and end up working in a biology library at a university library.

Not all articles are as felonious as his, but some are crap or
semi-crap.. Others are good except they omit things, important things.

So you shouldn't be assuming things because something is missing from
the articles you find, and more important, you should stop saying, WE
can safely assume. Speak for yourself. Not for us.






the wet cloth is to trap some of the hydrogen cyanide gas.