On Fri, 16 May 2014 04:33:21 +0000 (UTC), Ann Marie Brest
wrote:

On Fri, 16 May 2014 05:19:33 +0200, nestork wrote:

I agree with BobF; the wet cloth acts like a filter for both smoke
particles and fumes that would be soluble in water.

Until I read the referenced articles, I would also have believed that
filtering the smoke itself might have been a key safety issue.

But, we don't have any proof yet that smoke particles are anything
we care about from an inhalation standpoint during a cabin fire.

I think we're allowed to take judicial notice of everything else we've
learned in our lives.

It is frequenty reported that someone dies of smoke inhalation. That's
certainly something to care about. It may take longer than dying from
cynanide, but it's still bad.

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

In fact, this detailed article about all the negative effects of
a fire mainly discuss "smoke density" as a visual impairment factor,
and not as a critical inhalent (see page 39 of 47):

"Compilation of Data on the Sublethal Effects of Fire Effluent"
http://fire.nist.gov/bfrlpubs/fire09/PDF/f09033.pdf

What we seem to care about is hydrogen cyanide, which is soluble
in water. So the web towel apparently absorbs the HCN before you do.

On page 19 of 47, there is a table of the results of experiments
of HCN gases on a variety of mammals, since they say only one
human study was ever done. However, it's hard for me to
extrapolate that table to what happens in a real cabin fire.

So, what we really need is the key datapoint:
a. What is the concentration of HCN in a typical aircraft fire?

Who says there is a typical aircraft fire wrt HCN?