Medal Winners: Air Traffic Control Tapes

On 2 Feb 2006 05:06:53 -0800, "Bryan Martin"
wrote:

Try searching on the terms "carbon dioxide poisoning" and
"Hypercapnia" instaid. CO2 is toxic but is nowhere near as toxic as CO.
CO2 can act as a simple asphyxiant and kill by displacing oxygen or it
can kill from its toxic effects. It's much more likely to kill by
asphyxiation. It generally takes some unusual circumstances to
encounter its toxic effects and it takes a fair amount of time for
these effects to become dangerous. This is probably why it's not
usually considered a poison, usually it will suffocate you long before
it can poison you. CO will nearly always kill from its toxic effects
rather than simple asphyxiation because there is rarely enough of it
around to displace much oxygen in the atmosphere. CO2 poisoning is
usually only a concern if you are breathing a canned atmosphere with
plenty of oxygen but no way to get rid of the CO2.

carbon monoxide is about 210 times as active in binding with
hemoglobin as oxygen. carbon monoxide can react out all of your
hemoglobin so that no oxygen transport occurs and you die of
asphyxiation. (only about 10% of oxygen dissolves in plasma and that
isnt enough to keep you alive)

carbon dioxide in the blood forms carbonic acid and can alter the
blood pH enough to denature enzyme reactions in the body.
(a lot of the enzymes are curled up long molecules that are only
chemically active when certain parts of molecular loops are in near
proximity. when denatured through pH or temperature they straighten
out and the chemical processes they are involved with simply stop.)

Stealth pilot

"Bryan Martin" wrote in message ups.com...
Were there any chemical fumes in that tank he might have inhaled along
with the nitrogen?


No. The vessel had been pressure purged with nitrogen for the job before it was opened.



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"Stealth Pilot" wrote in message ...
snip

carbon dioxide in the blood forms carbonic acid and can alter the
blood pH enough to denature enzyme reactions in the body.
(a lot of the enzymes are curled up long molecules that are only
chemically active when certain parts of molecular loops are in near
proximity. when denatured through pH or temperature they straighten
out and the chemical processes they are involved with simply stop.)

Stealth pilot

I knew about the carbonic acid and the pH. I wasn't sure of the damage mechanism though. Very interesting. Thanks,
Stealth.

Joe Schneider
8437R



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On 2 Feb 2006 04:08:50 -0800, "Bryan Martin"
wrote:

Were there any chemical fumes in that tank he might have inhaled along
with the nitrogen?

JJS wrote:
"Bryan Martin" wrote in message
oups.com...
snip

Releasing N2 in a sealed space will simply increase the pressure in the
room and cause no particular breathing problems because the room will
still have enough oxygen in it to breath. You won't have a problem

N2 will not mix unless there is air circulation. This is one of the
things we learned with vessel entry and permits. In industry, at least
in the states, a person is not allowed to enter a closed vessel,
container, or even hole in the ground much over waist deep without a
safety harness, rope to the outside world, and enough muscle on the
outside to pull them out should they become responsive.

Even when entering underground pump rooms we had to be tied to the
outside world unless there was forced ventilation and even then some
one had to be present on the outside.

until the pressure gets high enough for the toxic effects of N2 to show
up (nitrogen narcosis). This takes several atmospheres of pressure.

Although part of what you say is true, I disagree with the above paragraph. In particular the part insinuating that
the nitrogen has to be pressurized to be toxic. I had a job related experience in which a contractor working under
supplied breathing air respirator had a near fatal incident. The catalyst vessel he was working in was under
nitrogen atmosphere to prevent the catalyst from going pyrophoric. There was no pressure on the vessel and the

This completely misses the most dangerous aspect of N2 in a closed
space (vessel entry). Narcosis is not a problem at normal atmospheric
pressure. N2 will not mix with the air unless there is some form of
forced circulation. The N2 will displace the O2 and lighter gasses
causing the person suffocate. N2 gives no warning either.

Roger Halstead (K8RI & ARRL life member)
(N833R, S# CD-2 Worlds oldest Debonair)
www.rogerhalstead.com

Joe Schneider
8437R

On Thu, 2 Feb 2006 19:40:38 -0600, "JJS" jschneider@remove socks
cebridge.net wrote:


"Bryan Martin" wrote in message ups.com...
Were there any chemical fumes in that tank he might have inhaled along
with the nitrogen?


No. The vessel had been pressure purged with nitrogen for the job before it was opened.

Then he committed a sin for which job termination is usually
proscribed at most companies now days. You never, ever enter a vessel
that has been N2 purged unless bringing your own breathing air by
tank or hose. He entered without checking the O2 level and almost
suffocated.

Roger Halstead (K8RI & ARRL life member)
(N833R, S# CD-2 Worlds oldest Debonair)
www.rogerhalstead.com



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"Roger" wrote

Then he committed a sin for which job termination is usually
proscribed at most companies now days. You never, ever enter a vessel
that has been N2 purged unless bringing your own breathing air by
tank or hose. He entered without checking the O2 level and almost
suffocated.
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
The first post about this said:

The catalyst vessel he was working in was under
nitrogen atmosphere to prevent the catalyst from going pyrophoric. There
was no pressure on the vessel and the
manway was open. He removed is mask to spit, then inhaled before putting it
back on. Instead of passing out, he
instantly went into violent convulsions and dropped the mask. Even with an
attendant equipped with a radio, and a
tripod, winch, and lanyard already set up and attached we only got him out
of the vessel alive by the grace of God.
--
Jim in NC

Morgans wrote:


"Roger" wrote

Then he committed a sin for which job termination is usually
proscribed at most companies now days. You never, ever enter a vessel
that has been N2 purged unless bringing your own breathing air by
tank or hose. He entered without checking the O2 level and almost
suffocated.

^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
The first post about this said:

The catalyst vessel he was working in was under
nitrogen atmosphere to prevent the catalyst from going pyrophoric.
There was no pressure on the vessel and the
manway was open. He removed is mask to spit, then inhaled before
putting it back on. Instead of passing out, he
instantly went into violent convulsions and dropped the mask. Even with
an attendant equipped with a radio, and a
tripod, winch, and lanyard already set up and attached we only got him
out of the vessel alive by the grace of God.

There HAD to be something else in the atmosphere, Jim.

N2 just doesn't do that (does it???)

Richard

On Fri, 03 Feb 2006 06:05:45 GMT, Richard Lamb
wrote:

Morgans wrote:


"Roger" wrote

Then he committed a sin for which job termination is usually
proscribed at most companies now days. You never, ever enter a vessel
that has been N2 purged unless bringing your own breathing air by
tank or hose. He entered without checking the O2 level and almost
suffocated.

^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
The first post about this said:

The catalyst vessel he was working in was under
nitrogen atmosphere to prevent the catalyst from going pyrophoric.
There was no pressure on the vessel and the
manway was open. He removed is mask to spit, then inhaled before
putting it back on. Instead of passing out, he
instantly went into violent convulsions and dropped the mask. Even with
an attendant equipped with a radio, and a
tripod, winch, and lanyard already set up and attached we only got him
out of the vessel alive by the grace of God.

There HAD to be something else in the atmosphere, Jim.

N2 just doesn't do that (does it???)

Richard

N2 doesn't do anything except displace O2 Lack of O2 normally causes
the victim to just pass out almost instantly followed by convulsions
then the cessation of respiration. ( quoted directly from the ontario
mine rescue handbook)

"Roger" wrote in message news
Then he committed a sin for which job termination is usually
proscribed at most companies now days. You never, ever enter a vessel
that has been N2 purged unless bringing your own breathing air by
tank or hose. He entered without checking the O2 level and almost
suffocated.

Roger Halstead (K8RI & ARRL life member)
(N833R, S# CD-2 Worlds oldest Debonair)
www.rogerhalstead.com

Roger, did you miss my post and just reply to the response that was snipped by Bryan Martin without him indicating he
did so?

It was I who filled out and signed the safe work and confined space entry permits. One of my direct reports took the
gas samples with a handheld gas meter. The confined space entry was done correctly per OSHA 1910.146 confined space
procedures. At my place of employment we have to make confined space entries on a routine basis.

An attendant was present. An Emergency Response Team was on standby. One thing though, there was no forced air
ventilation. He was using a supplied air respirator (air line mask) with a backup egress system. This was a
professional contract company that does IDLH confined space entries for catalyst work as their sole source of income.
Forced air ventilation will not make a "confined space" a "non-confined space" per OSHA. Ability to egress is a
consideration unto itself. There are permit required and non-permit required confined spaces. (I never liked that
terminology as they both require permits). IDLH atmospheres are permit required.

Roger, I've been reading your posts here for years and you have my respect. It seems as we both have some job
related experience with confined space entries. I've been doing it for 28 years and I sure don't consider myself an
expert on the subject. But please help educate me. Why did the victim go into convulsions instantly if he was
suffocating and why did it take months for him to recover? Like I said, I am not an expert on this, I'm only
relating my experiences. And in my experience nitrogen can be deadly even without being pressurize and without
"suffocating" you. And yes I know that air is 78% nitrogen.

I think this thread has drifted way to far off topic. For anyone else still interested go here Go here if you'd like
to read up on confined space requirements.
http://www.osha.gov/pls/oshaweb/owad...able=STANDARDS

Joe Schneider
8437R



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"Drew Dalgleish" wrote in message ...
On Fri, 03 Feb 2006 06:05:45 GMT, Richard Lamb
wrote:

Morgans wrote:


"Roger" wrote

Then he committed a sin for which job termination is usually
proscribed at most companies now days. You never, ever enter a vessel
that has been N2 purged unless bringing your own breathing air by
tank or hose. He entered without checking the O2 level and almost
suffocated.

^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
The first post about this said:

The catalyst vessel he was working in was under
nitrogen atmosphere to prevent the catalyst from going pyrophoric.
There was no pressure on the vessel and the
manway was open. He removed is mask to spit, then inhaled before
putting it back on. Instead of passing out, he
instantly went into violent convulsions and dropped the mask. Even with
an attendant equipped with a radio, and a
tripod, winch, and lanyard already set up and attached we only got him
out of the vessel alive by the grace of God.

There HAD to be something else in the atmosphere, Jim.

N2 just doesn't do that (does it???)

Richard

N2 doesn't do anything except displace O2 Lack of O2 normally causes
the victim to just pass out almost instantly followed by convulsions
then the cessation of respiration. ( quoted directly from the ontario
mine rescue handbook)

Drew, Can you point me to a link. A very quick google search didn't turn up much from Ontario. I'd like to verify
the "lack of O2 normally causes the victim to pass out almost instantly". Ever see someone in a choke lose
consciousness instantly or go into convulsions after they pass out. I've seen them go unconscious but it took
minutes not seconds and I've never witnessed follow up convulsions.

Joe Schneider
8437R



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