Inert gas asphyxiation

Inert gas asphyxiation is a form of <a href="/facts/Asphyxiation/bahl3DJf">asphyxiation</a> which results from breathing a physiologically <a href="/facts/Inert_gas/3EkBEoYh">inert gas</a> in the absence of <a href="/facts/Oxygen/acyn6o8r">oxygen</a>, or a <a href="/facts/Hypoxia_(medicine)/JWV04G89">low amount of oxygen (hypoxia)</a>, rather than <a href="/facts/Atmospheric_air/FV97Am25">atmospheric air</a> (which is composed largely of nitrogen and oxygen). Examples of physiologically inert gases, which have caused accidental or deliberate death by this mechanism, are <a href="/facts/Argon/QX6NRH6d">argon</a>, <a href="/facts/Helium/yRul93TG">helium</a> and <a href="/facts/Nitrogen/Nf1QpGDz">nitrogen</a>. The term "physiologically inert" is used to indicate a gas which has no toxic or anesthetic properties and does not act upon the heart or hemoglobin. Instead, the gas acts as a simple diluent to reduce the oxygen concentration in inspired gas and blood to dangerously low levels, thereby eventually depriving cells in the body of oxygen.
According to the <a href="/facts/U.S._Chemical_Safety_and_Hazard_Investigation_Board/2Yxzd2r9">U.S. Chemical Safety and Hazard Investigation Board</a>, in humans, "breathing an oxygen deficient atmosphere can have serious and immediate effects, including unconsciousness after only one or two breaths. The exposed person has no warning and cannot sense that the oxygen level is too low." In the US, at least 80 people died from accidental nitrogen asphyxiation between 1992 and 2002. Hazards with inert gases and the risks of asphyxiation are well-established.
An occasional cause of accidental death in humans, inert gas asphyxia has been used as a suicide method. Inert gas asphyxia has been advocated by proponents of <a href="/facts/Euthanasia/aYfNlLna">euthanasia</a>, using a gas-retaining plastic hood device colloquially referred to as a <a href="/facts/Suicide_bag/0tp2uT0c">suicide bag</a>.
Nitrogen asphyxiation has been approved in some places as a method of <a href="/facts/Capital_punishment/4pbmeUIb">capital punishment</a>. In the world's first instance of its use, on January 25, 2024, <a href="/facts/Alabama/1Xk8EveN">Alabama</a> executed convicted murderer <a href="/facts/Kenneth_Eugene_Smith/fLoNXsqE">Kenneth Eugene Smith</a> via this method. It was used once again in the <a href="/facts/Execution_of_Alan_Eugene_Miller/BxAWTLyI">execution of Alan Eugene Miller</a> on September 26, 2024, the execution of <a href="/facts/Murder_of_Vickie_Deblieux/EYT166ID">Carey Dale Grayson</a> on November 21, 2024, the execution of <a href="/facts/Demetrius_Terrence_Frazier/6mfB04El">Demetrius Terrence Frazier</a> on February 6, 2025, the execution of <a href="/facts/Jessie_Hoffman_Jr./3NDKLPwj">Jessie Hoffman Jr.</a> on March 18, 2025, and the execution of Gregory Hunt on June 10, 2025.
Alternatively, the use of the term hypoxia has been used but this term is flawed given hypoxia does not necessarily imply death. On the other hand, asphyxiation is technically incorrect given <a href="/facts/Respiration_(physiology)/KKWAJIbd">respiration</a> continues and the carbon dioxide metabolically produced from the oxygen inhaled prior to inert gas asphyxiation can be exhaled without restriction, which can prevent acidosis and the strong urge to breathe caused by <a href="/facts/Hypercapnia/wBArR1mW">hypercapnia</a>.

Inert gas asphyxiation open-in-new

Inert gas asphyxiation