What isn't an asphyxiant?

Question

As I understand it, an asphyxiant displaces oxygen in your lungs and leads to suffocation. What I don't understand is, how isn't any gas besides oxygen considered an asphyxiant? Anything can displace oxygen and lead to suffocation, because you can breathe too much of it instead of getting oxygen.

Answer 1

These gases in 99.9% purity would be deadly, however they are usually mixed with oxygen, and therefore not lethal.

Since the air (oxygen, rare gases plus impurities) is all around us, these gases in a concentrated state are usually released to mix again with the air.

The 7 common rare gases are separated from air by temperature and barometric changes. Air is frozen, and layers of gases separate. This couldn't be done to a human body inside lungs.

I hope this helps.

Answer 2

Your right. Even pure nitrogen is an asphyxiant by that definition. However, toxic asphyxiants, such as CO, interfere with the uptake of oxygen by being more preferentially bonded to red-blood cells.