The Peaceful Pill eHandbook Introducing the Gases: Nitrogen, Argon & Helium
By way of recap, there is nothing special about the particular type of inert gas used with an Exit bag. Indeed, any gas that does not react with the body and that is odorless and available in a compressed form, is suitable. Most often the choice of gas is determined by what is available. The three principal inert gases used with an Exit bag are nitrogen, helium and argon.
Compressed inert gases are generally available in high pressure cylinders which are leased from commercial gas supply companies (such as BOC, Linde or Air Liquide). However, leasing a cylinder of compressed gas in this way leaves a paper trail and there is no anonymity. These compressed gas cylinders are often large, heavy and difficult to transport. Suspicion could arise if an elderly or sick person rents a cylinder from their local gas outlet. If a friend were to collect the cylinder for them, this person could become legally implicated in assisting their suicide. These issues are disincentives to leasing from a commercial gas supplier.
Suitable, take-home cylinders of nitrogen, helium and argon can sometimes be purchased outright online and used effectively with the Exit bag.