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States Turn To an Unproven Method of Execution: Nitrogen Gas (nytimes.com)
States are reportedly turning to nitrogen gas to carry out the death penalty. "Oklahoma, Alabama and Mississippi have authorized nitrogen for executions and are developing protocols to use it, which represents a leap into the unknown," reports The New York Times. "There is no scientific data on executing people with nitrogen, leading some experts to question whether states, in trying to solve old problems, may create new ones." Slashdot reader schwit1 shares an excerpt from a report via The New York Times: What little is known about human death by nitrogen comes from industrial and medical accidents and its use in suicide. In accidents, when people have been exposed to high levels of nitrogen and little air in an enclosed space, they have died quickly. In some cases co-workers who rushed in to rescue them also collapsed and died. Nitrogen itself is not poisonous, but someone who inhales it, with no air, will pass out quickly, probably in less than a minute, and die soon after -- from lack of oxygen. The same is true of other physiologically inert gases, including helium and argon, which kill only by replacing oxygen.
Death from nitrogen is thought to be painless. It should prevent the condition that causes feelings of suffocation: the buildup of carbon dioxide from not being able to exhale. Humans are highly sensitive to carbon dioxide -- too much brings on the panicky feeling of not being able to breathe. Somewhat surprisingly, the lack of oxygen doesn't trigger that same reflex. Someone breathing pure nitrogen can still exhale carbon dioxide and therefore should not have the sensation of smothering.
Death from nitrogen is thought to be painless. It should prevent the condition that causes feelings of suffocation: the buildup of carbon dioxide from not being able to exhale. Humans are highly sensitive to carbon dioxide -- too much brings on the panicky feeling of not being able to breathe. Somewhat surprisingly, the lack of oxygen doesn't trigger that same reflex. Someone breathing pure nitrogen can still exhale carbon dioxide and therefore should not have the sensation of smothering.
Inert gas narcosis on air/nitrox doesn't become a significant concern until past 4ata / 100fsw. For air that's a PPN2 of 3.12. Breathing 100% N2 at 1 ata wouldn't even remotely induce any type of narcosis. This is different the breathing in fresh N2 with each breath. Breathing is controlled by CO2 levels and this method tricks the body into thinking everything is fine by keeping CO2 levels low in the body. Very effective... you never know what hit you. Now why are we trying to "solve old problems"? That's purely a political problem not a technical problem.
You've apparently never been around a pig farm in real life. They make those sounds when their distressed by new things. Unfamiliar locations, being stuck in something. They dont make them from being suffocated by nitrogen. Nitrogen doesn't give any signals to the body there is a problem. You simply pass out. Google OSHA nitrogen accidents to find out how quickly and how dangerous it is.
It's a basic principle of osmosis. Basically, osmosis means that if you have two different solutions (chemistry definition) that pass by each other with a semi-permeable membrane in between, that the parts of the solutions that can pass through the membrane will tend to equalize in concentration on both sides of the membrane.
When you breathe, there are two solutions (your blood and the air) that are separated by a semi-permeable membrane (your lungs). The air is mostly nitrogen (78%) and about about 21% oxygen in it. Your blood has oxygen and CO2 in it. The membrane in your lungs allows oxygen and CO2 to pass through it.
In the normal case, the amount of oxygen in your blood is less than the amount of oxygen in the air. The amount of CO2 in your blood is also higher than the amount of CO2 in the air. Your body takes the Oxygen out of your blood, converts it in to CO2 through metabolism, and puts the CO2 back in to your blood.
Since the concentration of oxygen in your blood is lower than the concentration of oxygen in your lungs, oxygen will move from the air in your lungs in to your blood until the two concentrations equalize. Same for CO2...The higher concentration of CO2 in your blood will move to the air in your lungs until the two concentrations equalize. Then you exhale the low-oxygen/high-CO2 air in your lungs and inhale fresh air...repeat.
In order for the above process to work, the membrane in your lungs has to be a two-way street. Oxygen needs to come in, CO2 needs to go out. The membrane is bidirectional.
The way a Nitrogen chamber works is that the gas in the nitrogen chamber is very close to 100% nitrogen. The percentage of both oxygen and CO2 in the air is nearly zero. You now breath this new solution in and osmosis works the same way. The oxygen and CO2 concentrations between the two solutions equalizes.
So you have blood returning to your lungs that has a high-concentration of CO2 and a low-concentration of Oxygen. The solution on the other side of the membrane in your lungs is pretty much 0% oxygen and 0% CO2. Since the concentrations want to equalize, this means that both CO2 AND oxygen from your blood is moving to the air in your lungs. Which you then exhale. This effectively causes oxygen to leave your body.
If the concentration of Oxygen in the blood returning to your lungs is at 16%, then when the oxygen in your blood equalizes with the 0% oxygen gas in your lungs, it causes you to now have 8% oxygen in your blood and 8% oxygen in your lungs. You now exhale causing that oxygen that was in your blood and now in your lungs to leave your body, inhaling a "fresh breath" of nearly 100% nitrogen...8% oxygen in your blood and 0% oxygen in your lungs will equalize at 4%...etc.
Holding your breath means the air in your lungs still has oxygen in it. 20% oxygen in your lungs (normal air), 16% oxygen in your blood. They will both equalize at 18%. Now when the blood comes around again, you've got 12% oxygen in your blood and 18% oxygen in your lungs...it equalizes at 15%...etc.
The rate at which the oxygen level in your blood lowers when you hold your breath is much less than the rate it lowers when you breath 100% nitrogen air.
Holding your breath does have the downside of also not exhaling the CO2 in your blood. It's the high concentrations of CO2 in your blood that cause the suffocation feeling. Holding your breath won't let the CO2 out of your lungs and blood. Breathing in Nitrogen causes the CO2 to respirate out of your body normally. This is why you don't feel like you're suffocating when you breath 100% nitrogen air. They say that your vision quickly fades, you shortly afterwards pass out, and then shortly after that die.