alive&kickin
Hazard to Others
Posts: 100
Registered: 10-11-2012
Member Is Offline
Mood: No Mood
|
|
olfactory fatigue
Looking for some information and coming up blank. Just out of curiosity, as a hypothetical, if there was an enclosed area with a very slow
ventilation system and a release of hydrogen sulfide, hydrogen cyanide, etc. (chemicals that kill your sense of smell), how long would you have to be
outside the area before you could reenter and smell it again? Not looking for someone to test this one , just curious and couldn't find any kind of info.
|
|
|
macckone
Dispenser of practical lab wisdom
Posts: 2168
Registered: 1-3-2013
Location: Over a mile high
Member Is Offline
Mood: Electrical
|
|
Both hydrogen cyanide and sulfide can kill your sense of smell. It may never fully recover. I think for recovery it is going to be very dependent on
the individual, expose concentration and length of exposure. And like I said at the upper end you may never fully recover.
|
|
|
diddi
National Hazard
Posts: 723
Registered: 23-9-2014
Location: Victoria, Australia
Member Is Offline
Mood: Fluorescent
|
|
That's an experiment I am not will to try 
People have commented on my very acute sense of smell, and I have bee exposed to chems for 35 years. Always pays to be careful.
[Edited on 5-12-2015 by diddi]
Beginning construction of periodic table display
|
|
|
phlogiston
International Hazard
Posts: 1379
Registered: 26-4-2008
Location: Neon Thorium Erbium Lanthanum Neodymium Sulphur
Member Is Offline
Mood: pyrophoric
|
|
You won't have to, it has been done.
Stuck B.A. et al (2013) Chemical Senses 39(2):151-157
http://chemse.oxfordjournals.org/content/39/2/151
Briefly scanning the paper 'diagonally' I think the brief answer is that the recovery time is concentration dependent and on the order of several
minutes. But I could not be bothered to read it properly, so have a look for yourself if you are really interested.
-----
"If a rocket goes up, who cares where it comes down, that's not my concern said Wernher von Braun" - Tom Lehrer |
|
|
careysub
International Hazard
Posts: 1339
Registered: 4-8-2014
Location: Coastal Sage Scrub Biome
Member Is Offline
Mood: Lowest quantum state
|
|
Quote: Originally posted by phlogiston  | You won't have to, it has been done.
Stuck B.A. et al (2013) Chemical Senses 39(2):151-157
http://chemse.oxfordjournals.org/content/39/2/151
Briefly scanning the paper 'diagonally' I think the brief answer is that the recovery time is concentration dependent and on the order of several
minutes. But I could not be bothered to read it properly, so have a look for yourself if you are really interested. |
Thanks for finding this.
The highest H2S concentration they tested was 8 ppm (lowest 2 ppm). For this full densensitization took from 40-110 sec (mean 70), some recovery after
even 5 seconds and substantial recovery at sec. At these low concentrations the actual concentrations did not have any effect on the time for either
process. Unfortunately this not provide much guidance for what happens at say, 100 ppm.
Olfactory desensitization is a general phenomenon, but H2S's ability to cause it is unusually pronounced.
I have never read anything to indicate desensitization by H2S or HCN is anything but temporary, unless perhaps actual gross poisoning occurs which is
an entirely different matter.
|
|
|
macckone
Dispenser of practical lab wisdom
Posts: 2168
Registered: 1-3-2013
Location: Over a mile high
Member Is Offline
Mood: Electrical
|
|
Above 50ppm tissue damage can occur to the cornea. At 100ppm permanent damage to other tissue can occur. 350ppm is considered deadly. The usual
level for alarms in industrial areas and plants is 10ppm.
|
|
|
Heavy Walter
Hazard to Others
Posts: 127
Registered: 17-12-2015
Location: Argentina
Member Is Offline
Mood: No Mood
|
|
Being able to rely in other indicators, I would avoid to use the nose as a measuring instrument.
Look for "anosmia" in Wikipedia. The reduction or loss of sense of smell.
In my particular case, I discovered my reduction of this sense by comparison with fellows in the lab. This was by chance and I suspect I realized
late.
May be my age, may be the exposure to different dangerous products from time to time or may be a combination of effects. Hard to tell...
|
|
|
chemrox
International Hazard
Posts: 2961
Registered: 18-1-2007
Location: UTM
Member Is Offline
Mood: LaGrangian
|
|
Years ago I talked with industrial chemists making bromoalkanes. They didn't smell it anymore and were habituated to them; not taking long vacations.
The concentrations of H2S required to cause tissue damage are beyond the extinction concentration according to some geochemist friends. At those
levels you'd be lucky to survive. A colleague was pulled from an active caldera and taken away by chopper to recover in ICU. He recovered; including
the ability to smell H2S, He was unlucky with his harness but lucky with available helicopters.
"When you let the dumbasses vote you end up with populism followed by autocracy and getting back is a bitch." Plato (sort of)
|
|
|
macckone
Dispenser of practical lab wisdom
Posts: 2168
Registered: 1-3-2013
Location: Over a mile high
Member Is Offline
Mood: Electrical
|
|
| Quote: Originally posted by chemrox | | Years ago I talked with industrial chemists making bromoalkanes. They didn't smell it anymore and were habituated to them; not taking long vacations.
The concentrations of H2S required to cause tissue damage are beyond the extinction concentration according to some geochemist friends. At those
levels you'd be lucky to survive. A colleague was pulled from an active caldera and taken away by chopper to recover in ICU. He recovered; including
the ability to smell H2S, He was unlucky with his harness but lucky with available helicopters. |
The various points where tissue damage (50-100ppm) occur are well above the point of loss of ofactory perception (2ppm) but also well under the point
of death(350ppm). In any case getting exposed above 10ppm on a regular basis seems like a bad idea although the data suggests perceptible tissue
damage doesn't occur until a much higher level. Of course any individual is going to react differently so some hearty soul might be able to withstand
500pm without any long term effects but another person with asthma and copd might die at 1ppm. These values are estimated averages since we don't
experiment on humans. Take them as you will and don't expose youself unnecessarily.
|
|
|
deewee
Harmless
Posts: 3
Registered: 6-1-2016
Member Is Offline
Mood: No Mood
|
|
Small concentrations also bring problems: headache, dizziness, fatigue, and irritation, besides the smell stick nostrils for weeks in some cases
|
|
|
TheChemiKid
Hazard to Others
Posts: 493
Registered: 5-8-2013
Location: ̿̿ ̿̿ ̿'̿'̵͇̿̿з=༼ ▀̿̿Ĺ̯̿̿▀̿ ̿ ༽
Member Is Offline
Mood: No Mood
|
|
I once inhaled a lot of HCl and I can't smell it anymore, even 2 years later
When the police come
\( * O * )/ ̿̿ ̿̿ ̿'̿'̵͇̿̿з=༼ ▀̿̿Ĺ̯̿̿▀̿ ̿ ༽
|
|
|
![[*]](images/xpblue/default_icon.gif){kind=icon}
