A while ago, I had occasion to breathe 100% nitrogen from an oronasal mask.
Since this is a serious failure mode, I wanted first hand experience of it.
I took the mask and breathed normally for 10 seconds. I experienced no
symptoms. I handed the mask back and asked the life support guy to confirm
it was pure nitrogen. He did. About then I experienced some disorientation.
I was in no danger of losing consciousness, but had I been doing physical
activity, I would have paused. The disorientation passed after a few
seconds.
So short answer, under no physical stress, 10 seconds is fine. That said,
nitrogen is probably the most dangerous non-toxic gas you can breathe. It
feels exactly the same as air when you breathe it. Your I-can't-breathe
alarms are tied to excess CO2; breathing nitrogen doesn't trigger them. If
you enter a pure nitrogen atmosphere, you won't feel any symptoms for
several seconds. Then your plasma oxygen concentration will crash so fast
that you will lose consciousness before you know you have a problem,
Henry's advice is immediately remove oxygen- saturated clothing is spot on
if there is an ignition source nearby, or if you are certain your clothing
is saturated with oxygen. In the absence of those conditions, your
knowledge of that advice will motivate you to convince yourself that your
clothing is *not* saturated with oxygen. That is a potentially
life-threatening cognitive error, which almost every human will make at
almost every opportunity available.
My advice would be to immediately move away from the oxygen source,
promptly but unobtrusively remove your outerwear (sweater, coat, hat,
etc.), tell someone of your concern, and prepare yourself emotionally to
strip naked in five seconds. Ideally, the person you tell will
unubtrusively pick up a fire bottle and prepare to use it. I specify
unobtrusively to bias against the cognitive error above. Humans also make
better decisions when stakes are low than when they are high, and taking
off your clothing in public in a society with a nudity taboo is a high
stakes decisions. (Being on fire excuses you from the nudity taboo, but
that's too late: if you are part of an oxygen-fed, you will sustain serious
injury before you can react to the flames.)
On Wed, Apr 20, 2016 at 11:26 AM David Gregory <david.c.gregory@xxxxxxxxx>
wrote:
If breathing pure gn2, loss of consciousness in as little as 8-10
seconds. 3 or 4 breaths?
On Apr 20, 2016, at 10:50 AM, John Dom <johndom@xxxxxxxxx> wrote:full lungfull of pure helium or nitrogen won't kill you.
Ben Brockert wrote on 200416:
You're not going to suffocate by taking a sniff of nitrogen. Even a
breathe pure nitrogen. My guess is 5-7 times before you pass out. Anybody
Not because of a whiff of N2 no. I do not know how many times one can
knows better?
I read of people stepping down a few steps down a ladder inside a tank,unaware it had been nitrogen purged. The treacherous thing is one breathes
quite normally in N2 but O2 is missing: sudden collapse and death is
likely, without warning or ill feeling. Such happened on several occasions
in chemical industry, even some who went down for help without an air
blanket perished.
jd