Lowest & highest Oxygen content (%) in AIR, which we can breathe comfortably ?

Question

We breathe Air having 21 % Oxygen. What is the safest limit of lowest and highest Oxygen content in Air, which we can breathe feeling comfortable?

Answer 1

good question. the least amount of oxygen that might keep a person alive is about 13 to 15% according to studies done in the 60's and 70's. however if you were in a hyperbaric chamber 13% could likely keep you quite comfortable. of course this is assuming that the air you are breathing is not contaminated with high concentrations of any other gases like CO2 or CO.

when it comes to high concentrations of oxygen, greater then 50% according to some medical authorities, then oxygen becomes toxic. the earliest effects occurring within 24 to 48 hours; symptoms being a cough, sub sternal pain, and tracheal burning. with continued exposure mast cells may degranulate, secretory cells begin to secrete more mucus like substance; as things progress, morphological changes at the cellular level occur and may be irreversible, resulting in scarring of bronchial tissue and thickening of cell membranes.

Answer 2

You can breathe 100% oxygen comfortably. As far as the lowest percentage, if varies from person to person. People who live at high altitudes have adapted to breathe where the oxygen content is much lower than at sea level. Also an athletic person would be able to maintain his blood saturation much better than a fat guy at the same oxygen level.

Answer 3

If you breathe 100% oxygen for an extended period of time (days, weeks...) you will eventually knock out your hypoxic drive. COPD patients cannot tolerate high flow (more than the standard 2LPM most of them get via nasal cannula) oxygen for very long specifically for that reason (for example). You will NOT get "high" off of oxygen though. As far as the lowest concentration... depends on your altitude and overall health. Room air (21%) is fine for most of us.

Answer 4

if you breathe 100% oxygen you'll be high as a kite. that's the only comfort you should have.

Answer 5

sdas