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Medical What if ?

  1. Jan 18, 2008 #1
    What if you were put in a room with the atmosphere composed of only oxygen(100%)? Would you die?
  2. jcsd
  3. Jan 18, 2008 #2
    Yes, you would.
  4. Jan 18, 2008 #3


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    Huh - I didn't think that was true, but it may be -- but it would take several days, at least: http://en.wikipedia.org/wiki/Oxygen_toxicity
  5. Jan 18, 2008 #4
    Even if it would take 100 years... anyway... one would die... :cry:
  6. Jan 18, 2008 #5


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    The NOAA limit used to be 24hrs on 1bar O2 - but that had a big safety margin.
    Higher partial pressures can give you interesting CNS symptoms much sooner!

    But in a sealed room you would die first of CO2 poisoning if there wasn't a system to remove it.
  7. Jan 21, 2008 #6
    ugh i am tired

    Not if you had a large enough room.
    I thought that you needed inert gases like nitrogen or helium (neon is toxic in larger quantities) in your blood to balance out the oxygen, but i do not know much about biology though. I think the only reason we need oxygen is the final electron acceptor at the end of the electron transport chain unless i'm getting myself confused with the inner workings of a plant.:confused:
  8. Jan 21, 2008 #7


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    I believe you do need to have a very tiny amount of CO2 in the air in order to maintain proper blood chemistry. I think this is the reason behind hyperventilating…you breathe in and out so much that your expel the CO2 produced in your lungs too quickly, causing one start to feel light-headed and possibly faint.

    Also consider that they used to use very high Oxygen environments for the astronauts in the space program…recall one of the reasons for the Apollo 1 fire disaster.
  9. Jan 22, 2008 #8


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    You can breathe pure oxygen - it's all a question of partial pressures.
    0.21bar O2 is what you breath normally, you can eithge rmake the rest up with Nitrogen or reduce the pressure and breath pure oxygen.
    At about 1bar 02 (ie. breathing pure oxygen at atmospheric pressure) you get slight lung irritation after about 24 hours.
    At higher partial pressures oxygen becomes toxic - it effects your centrla nervous system. The limit depending on who you work for, how much physical activity and how much danger you are in is between 1.4bar and 3bar. So recreational diving you would limit O2 to about 1.2 bar, either by having 40% oxygen at 3atmosphere of pressure or 21% at 6 atmospheres, you can handle upto about 2.5-3 bar if you are safely strapped down in a chamber.
    The effects of short term exposure to high O2 aren't necessarily themselves dangerous, you get muscle spasms with CNS but if you are 100m underwater this can be dangerous.

    The reason for complicated gas mixes ( nitrox/trimix/heliox) in diving is to acheive the pressure of the surrounding water while keeping the partial pressure of biologically active gases, especially oxygen, low enough by diluting them with inert gas.
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