[TheForge] Smoke & toxic gas poisoning (was: Auto darkening helmet)

[Bruce Freeman]

I suspect Frosty's tongue was in his cheek when he wrote this.

Nonetheless, let me point out that the degree of exposure is what
matters in cyanide poisoning.  Some poisons, like mercury and lead are
cumulative -- it's quite difficult to get them out of your body once
they are in.

Now, I'm a chemist, not a toxicologist, so my knowledge of this stuff
is from the practical standpoint of not getting myself poisoned while
doing my job.  My opinions should be considered in that light.

Cyanide, not so.  Cyanide has to reach some (rather low) concentration
before it's a danger to you.  If you get a sub-lethal dose, its
effects may linger (as you've reduced the ability of your blood to
carry oxygen), but if you're in good health you should recover
completely.   I happen to be able to smell it (pure HCN, not mixed in
smoke), though not everybody can, and I'm here to talk about it.  In
my case, if I smell it, I move away from the source (and stay away
because the nose fatigues).

Generally speaking, if you avoid nasty stuff like smoke, you're not
likely to get in trouble from its cyanide content.  OTOH, if you think
a little smoke won't hurt you -- well, remember Jim (Paw Paw) Wilson:
http://www.anvilfire.com/iForge/tutor.php?lesson=safety3/demo

There's actually a much more insidious toxic gas than HCN, namely H2S.
 Just the other day I was paddling on a creek and my paddle stirred up
the mud from on the bottom.  I was enveloped with the stench of rotten
eggs -- the odor of H2S.  I probably was in no danger as the crick was
fairly wide at that point, but had it been narrow with little air flow
it is conceivable that the H2S concentration could have been of
concern.  This is because the threshold of odor is about the same as
the threshold of toxicity for H2S, AND the nose fatigues.  There you
are, you get this whiff of rotten egg.  Then the smell goes away --
but you're still breathing it!  So, I paddled back out of that area.

On Mon, Jun 6, 2011 at 9:03 PM, Jerry Frost <akfrosty at mtaonline.net> wrote:

>
> This is the REAL downside to wearing wool as fire protection, the smoke
> contains cyanide. This was pointed out on a smithing forum yakking about
> this subject a few days ago. The upside is it takes a pretty serious
> exposure to wool or hair smoke to be hazardous unless you're sensitive and
> the smell is more than enough to clue you into taking care of the problem.
>
> Jer
-- 
Bruce
NJ