Inert gases

Inert gases are non-toxic gases that does not support human respiration and interacts little or not at all with other chemicals. If these present in significant amounts, they can cause damage or death. Oxygen deficiency can arise when using such gases. Inert gases have no odour, colour, or taste.

Nitrogen is a common inert gas, and so are the rare gases such as helium, argon, neon, methane, xenon, krypton, and, carbon dioxide. They are invisible and hence far more hazardous than poisonous gases like chlorine, ammonia, or hydrogen sulphide, which may be recognised by their odour at extremely low quantities.

The asphyxiating impact of inert gases happens in the absence of any pre-existing physiological indication that may alarm the sufferer. They have the ability to displace enough air to lower oxygen levels.

A lack of oxygen can induce dizziness, headaches, and speech problems, but the affected person is unable to recognise these symptoms as signs of asphyxiation. Asphyxiation causes fast loss of consciousness — at extremely low oxygen concentrations, this can happen in seconds.

Reference:

Inert Gas Narcosis – An Introduction by P. Unsworth, B.M., B.Ch., L.R.C.P.,

Principles of treatment of poisoning by higher oxides of Nitrogen by c. Prys-roberts

Inert gas asphyxiation From Wikipedia

CGA document SB-2 2007 Oxygen-Deficient Atmospheres

Inert gas From Wikipedia