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Kashaf Umar

What is the minimum air pressure the human body can tolerate if oxygen supply is not an issue?

Deeksha  Follow

At sea level, where atmospheric pressure is 1 atm and oxygen is about 21% the partial pressure of oxygen is enough to saturate hemoglobin.

The lowest tolerable pressure of air is about 0.47 atm (475 millibars of atmospheric pressure) - recorded at 5950m altitude.

At about 0.35 atm (less than 356 millibars at around 8000m) life is impossible. Pulmonary and cerebral edema lead to death.

Source: Wikipedia, Effects of high altitude on humans

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Graham Wolf  Follow
Sorry, my mistake. I mistook feet and meters in the table. There's still one mistake though: The lowest tolerable pressure (inhabited for two years) and 475 millibar figure is at the height of 5950 m. 5100 m is the height of the highest permanent settlement.More
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John Collins  Follow
You've got at least one number wrong. The "Death zone" at Mt Everest is considered to start at about 8000 meters, and the pressure there is about 0.75 atm. See More
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Josh-D. Davis  Follow
engineeringtoolbox.com/air-altitude-pressure-d_462.htmlMore
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Jamie E  Follow
Just to clarify, I didn't mean that the "Death zone" altitude is the answer to the question, just that your altitude and pressure numbers don't match. Also, I couldn't find those numbers in the linked article.More
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Jeff Goodman  Follow
@jarlemag In the article Death zone pressure was in milibars. I converted it to atm.More
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Craig 75  Follow

Disregarding hypoxia, the lowest atmospheric pressure the human body can withstand is around 6 percent sea level pressure, or 61.8 millibars, below that pressure the water and blood in your body starts to boil. Harry George Armstrong, a physician, and an airman, was the first to recognise this limit, which on Earth occurs at an altitude of roughly 63,000 feet, beyond which humans absolutely cannot survive in an unpressurised environment. The limit was named in his honour and so is called the Armstrong Limit. The lowest atmospheric pressure humans can breathe in, with a pure oxygen supply on hand, is roughly around 12.2 percent sea level air pressure or 121.7 millibars, the pressure found at 49,000 feet. Or, as a slightly madder alternative example, in a terraforming Mars situation, which might arise one day; a fit person could in theory walk around outside without a spacesuit on, but breathing from an oxygen tank, only when the atmospheric pressure got above about 120 millibars, and hope to survive for long.

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Francis F. Chen  Follow
For reference the natural atmospheric pressure on Mars is around 6 millibars.More
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Charles Danley  Follow
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Jeffrey Denenberg  Follow
Add some references to your claim.More
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