Can humans breathe an Argon-Oxygen atmosphere, where Argon substitutes the inert Nitrogen gas which currently populates our atmosphere? I didn't quite know which forum to stick this one in; I put it here because I only want to know if such a mixture of gases can be feasibly inhaled, without the prospect of early death by some physiological component.


1 Answer 1


One may think that Argon, being an inert noble gas, causes no harm at all and can perfectly replace N2 in a mix with oxygen. After all, you've been breathing Argon your whole life, since approximately 1% of the air is Argon:

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However, we are talking about a raise from 1% to 78%... and there are possible consequences here:

  1. Argon is way denser than N2: Argon has a density of 1.784 g/L, while N2 has a density of 1.251 g/L (O2 has a density of 1.428 g/l). So, Argon is 40% denser than N2 (and also denser than O2 and denser than air). Without taking into account ventilation and other forces, there is a risk of argon not mixing properly with the incoming "air" in your lungs.
  2. Argon is a narcotic: This may sound strange, but there are evidences that Argon has sedative properties. According to Nowrangi, Tang and Zhang (2014):

    Argon gas is considered a small noble gas element that has been applied in a number of fields. It has been generally classified as a nonreactive or inert gas providing a view that it does not contain any biologically active characteristics. In fact, argon has demonstrated characteristics such as narcosis [...] The mechanism in which argon displays its anesthetic ability has been suggested to be from the stimulation of γ-aminobutyric acid type-A receptors. (emphases mine)

As an additional information, there is an Argon-Oxygen mix, called Argox, which is used for decompression research only, not as a scuba-diving breathing mix.

Also, this question from WorldBuilding has some interesting information (and some wrong information as well).

In conclusion: this Argon-Oxygen mix is not harmless.

Source: Nowrangi, D., Tang, J. and Zhang, J. (2014). Argon gas: a potential neuroprotectant and promising medical therapy. Medical Gas Research, 4(1), p.3.


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