Gas chamber

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Gas chamber at Majdanek concentration camp

A gas chamber is an apparatus for killing humans or other animals with gas, consisting of a sealed chamber into which a poisonous or asphyxiant gas is introduced. Poisonous agents used include hydrogen cyanide and carbon monoxide.


General Rochambeau developed a rudimentary method in 1803, during the Haitian Revolution, filling ships' cargo holds with sulfur dioxide to suffocate prisoners of war. The scale of these operations was brought to larger public attention in the book Napoleon's Crimes (2005), although the allegations of scale and sources were heavily questioned.

In America, the utilization of a gas chamber was first proposed by Allan McLane Hamilton to the state of Nevada. Since then, gas chambers have been used as a method of execution of condemned prisoners in the United States and continue to be a legal execution method in three states, seeing legislated reintroduction with inert N2, although redundant in practice since the early 1990s.

Lithuania used gas chambers for civilian, penal use in the 1930s, with the last known execution carried out in 1940. The Soviet Union allegedly used the method to perform executions during the Great Purge, including by use of gas vans. Prisoners were gassed on the way to the Butovo firing range, where the NKVD normally executed its prisoners by shooting them. None of these saw mass use, however, and were strictly for "criminal" purposes.

Most notably, during the Holocaust large-scale gas chambers designed for mass killing were used by Nazi Germany from the late 1930s, as part of the Aktion T4, and later for its genocide program.

More recently, escapees from North Korea have alleged executions to have been performed by gas chamber in prison camps, often combined with medical experimentation.

Nazi Germany

Interior of Majdanek gas chamber, showing Prussian blue residue

Nazi Germany made extensive use of various types of gas chambers for mass-murder during the Holocaust.

Beginning in 1939, gas chambers were used as part of Aktion T4, an "involuntary euthanasia" program under which the Nazis murdered people with physical and intellectual disabilities, whom the Nazis considered "unworthy of life". Experiments in the gassing of patients were conducted in October 1939 in occupied Posen in Poland. Hundreds of prisoners were murdered by carbon monoxide poisoning in an improvised gas chamber. In 1940 gas chambers using bottled pure carbon monoxide were established at six killing centres in Germany. In addition to persons with disabilities, these centres were also used during Action 14f13 to murder prisoners transferred from concentration camps in Germany, Austria, and Poland. Concentration camp inmates continued to be murdered even after the euthanasia program was officially shut down in 1941.

During the invasion of the Soviet Union, mass executions by exhaust gas were performed by Einsatzgruppen using gas vans, trucks modified to divert engine exhaust into a sealed interior gas chamber.

Starting in 1941, gas chambers were used at extermination camps in Poland for the mass-murder of Jews, Roma, and other victims of the Holocaust. Gas vans were used at the Chełmno extermination camp. The Operation Reinhard extermination camps at Bełżec, Sobibór, and Treblinka used exhaust fumes from stationary diesel engines. In search of more efficient killing methods, the Nazis experimented with using the hydrogen cyanide-based fumigant Zyklon B at the Auschwitz concentration camp. This method was adopted for mass-murder at the Auschwitz and Majdanek camps. Up to 6,000 victims were gassed with Zyklon B each day at Auschwitz.

Most extermination camp gas chambers were dismantled or destroyed in the last months of World War II as Soviet troops approached, except for those at Dachau, Sachsenhausen and Majdanek. One destroyed gas chamber at Auschwitz was reconstructed after the war to stand as a memorial.

North Korea

Kwon Hyok, a former head of security at Camp 22, described laboratories equipped with gas chambers for suffocation gas experiments, in which three or four people, normally a family, are the experimental subjects. After the chambers are sealed and poison is injected through a tube, while scientists observe from above through glass. In a report reminiscent of an earlier account of a family of seven, Kwon claims to have watched one family of two parents, a son and a daughter die from suffocating gas, with the parents trying to save the children using mouth-to-mouth resuscitation for as long as they had the strength. Kwon's testimony was supported by documents from Camp 22 describing the transfer of prisoners designated for the experiments. The documents were identified as genuine by Kim Sang Hun, a London-based expert on Korea and human rights activist.


In 1937–1940, Lithuania operated a gas chamber in Aleksotas within the First Fort of the Kaunas Fortress. Previous executions were carried out by hanging or by shooting. However, these methods were viewed as brutal and in January 1937, the criminal code was amended to provide execution by gas which at the time was viewed as more civilized and humane. Lithuania considered and rejected execution by poison. Unlike the American or German model the Lithuanian gas chamber, built out of bricks, worked by inputting compressed lethal gas from an external storage cylinder (Černevičiūtė 2014). The first execution was carried on July 27, 1937: Bronius Pogužinskas, age 37, convicted of murder of five people from a Jewish family. Historian Sigita Černevičiūtė counted at least nine executions in the gas chamber, though records are incomplete and fragmentary. Of the nine, eight were convicted of murder. One of these, Aleksandras Maurušaitis, was also convicted of anti-government actions during the 1935 Suvalkija strike. The last known execution took place on May 19, 1940, for robbery. The fate of the gas chamber after the occupation by the Soviet Union in June 1940 is unclear.

Soviet Union

Soviet NKVD commander Isay Berg adapted vans with the storage compartment sealed and exhaust redirected inside it.

United States

Gas chamber usage in the United States.  Secondary method only   Previously used, but not presently   Never used Post-Furman uses by state and numbers

Gas chambers have been used for capital punishment in the United States to execute death row inmates. The first person to be executed in the United States by lethal gas was Gee Jon, on February 8, 1924. An unsuccessful attempt to pump poison gas directly into his cell at Nevada State Prison led to the development of the first makeshift gas chamber to carry out Jon's death sentence.

On December 3, 1948, Miran Thompson and Sam Shockley were executed in the gas chamber at San Quentin State Prison for their role in the Battle of Alcatraz.

In 1957, Burton Abbott was executed as the governor of California, Goodwin J. Knight, was on the telephone to stay the execution.

Since the restoration of the death penalty in the United States in 1976, 11 executions by gas chamber have been conducted. Four were conducted in Mississippi, 2 in Arizona, 2 in California, 2 in North Carolina, and 1 in Nevada. The first execution via gas chamber since the restoration of the death penalty was in Nevada in 1979, when Jesse Bishop was executed for murder. The most recent execution via gas chamber was in 1999. By the 1980s, reports of suffering during gas chamber executions had led to controversy over the use of this method.

At the September 2, 1983, execution of Jimmy Lee Gray in Mississippi, officials cleared the viewing room after 8 minutes while Gray was still alive and gasping for air. The decision to clear the room while he was still alive was criticized by his attorney. In 2007, David Bruck, an attorney specializing in death penalty cases, said, "Jimmy Lee Gray died banging his head against a steel pole in the gas chamber while reporters counted his moans."

During the April 6, 1992, execution of Donald Eugene Harding in Arizona, it took 11 minutes for death to occur. The prison warden stated that he would quit if required to conduct another gas chamber execution. Following Harding's execution, Arizona voted that all persons condemned to death after November 1992 would be executed by lethal injection.

Following the execution of Robert Alton Harris in 1992, a federal court declared that "execution by lethal gas under the California protocol is unconstitutionally cruel and unusual." However, this decision was vacated after California amended its statute to allow death row inmates to choose between lethal injection and the gas chamber. By the late 20th century, most states had switched to methods considered to be more humane, such as lethal injection. California's gas chamber at San Quentin State Prison was converted to an execution chamber for lethal injection.

As of 2020, the last person to be executed in the gas chamber was German national Walter LaGrand, sentenced to death before 1992, who was executed in Arizona on March 3, 1999. The U.S. Court of Appeals for the Ninth Circuit had ruled that he could not be executed by gas chamber, but the decision was overturned by the United States Supreme Court. The gas chamber was formerly used in Colorado, Maryland, Nevada, New Mexico, North Carolina and Oregon. Seven states (Alabama, Arizona, California, Mississippi, Missouri, Oklahoma, and Wyoming) authorize lethal gas if lethal injection cannot be administered, the condemned committed their crime before a certain date, or the condemned chooses to die in the gas chamber. Alabama, Mississippi, and Oklahoma specify the nitrogen hypoxia method, Arizona specifies the hydrogen cyanide method, and the other states do not specify the type of gas. In October 2010, Governor of New York David Paterson signed a bill rendering gas chambers illegal for use by humane societies and other animal shelters.

Method of use

Using hydrogen cyanide

The former gas chamber at New Mexico State Penitentiary, used only once in 1960 and later replaced by lethal injection. Executions in California were carried out in the gas chamber at San Quentin State Prison. It was modified for the use of lethal injection, but has been returned to its original designated purpose, with the creation of a new chamber specifically for lethal injection.

The hydrogen cyanide gas chamber is considered to be the most dangerous, most complicated, most time-consuming and most expensive method of administering the death penalty. It is also notoriously impossible to halt once initiated, which has occurred in the case of stays, such as in the case of Burton Abbott. The same event supposedly occurred in the final, completed execution of Caryl Chessman in 1960. The condemned person is strapped into a chair within an airtight chamber, which is then sealed. The executioner activates a mechanism which drops potassium cyanide (or sodium cyanide) pellets into a bath of sulfuric acid beneath the chair; the ensuing chemical reaction generates lethal hydrogen cyanide gas.

H 2 SO 4 + 2 NaCN ⟶ 2 HCN + Na 2 SO 4 {\displaystyle {\ce {H2SO4 + 2NaCN -> 2HCN + Na2SO4}}} or H 2 SO 4 + 2 KCN ⟶ 2 HCN + K 2 SO 4 {\displaystyle {\ce {H2SO4 + 2KCN -> 2HCN + K2SO4}}}

The gas is visible to the condemned, who is advised to take several deep breaths to speed unconsciousness. Nonetheless, the condemned person often convulses and drools and may also urinate, defecate, and vomit.

Following the execution the chamber is purged with air, and any remnant gas is neutralized with anhydrous ammonia, after which the body can be removed (with great caution, as pockets of gas can be trapped in the victim's clothing).

Excluding all oxygen

Nitrogen gas or oxygen-depleted air has been considered for human execution, as it can induce nitrogen asphyxiation. The victim detects little abnormal sensation as the oxygen level falls. This leads to asphyxiation (death from lack of oxygen) without the painful and traumatic feeling of suffocation, or the side effects of poisoning.

In April 2015, Oklahoma Governor Mary Fallin approved a bill allowing nitrogen asphyxiation as an execution method. On March 14, 2018, Oklahoma Attorney General Mike Hunter and Corrections Director Joe M. Allbaugh announced a switch to nitrogen gas as the state's primary method of execution. After struggling for years to design a nitrogen execution protocol, the State of Oklahoma announced in February 2020 that it was abandoning the project after finding a reliable source of drugs to carry out the lethal injection executions.

In 2018, Alabama approved nitrogen asphyxiation as an execution method and allowed death row inmates a choice of method. In September 2022, a court stayed the execution of Alan Eugene Miller, who was set to be executed by lethal injection. Miller asserted that he had chosen nitrogen hypoxia as his method of execution, as permitted by Alabama law, but the form documenting his choice had been lost. The court decided to stay the execution to allow for further investigation into his claim. On January 25, 2024, Kenneth Eugene Smith became the first person to be executed by nitrogen asphyxiation.

Further reading


  1. ^ Mobley, Christina. "A War Within the War". Haiti: An Island Luminous. Duke University. Archived from the original on 31 July 2020. Retrieved 25 April 2020.
  2. ^ Boot, Max (15 January 2013). Invisible Armies: An Epic History of Guerrilla Warfare from Ancient Times to the Present (hardcover 1st ed.). New York: W. W. Norton & Company. p. 99. ISBN 978-0-87140-424-4. Retrieved 25 April 2020.
  3. ^ Sinclair, B.W.; Sinclair, J.; Prejean, H. (2011). Capital Punishment: An Indictment by a Death-Row Survivor. Skyhorse Publishing. p. 27. ISBN 978-1-62872-134-8. Retrieved 12 October 2022.
  4. ^ Engel, H. (2016). Lord High Executioner: An Unashamed Look at Hangmen, Headsmen, and Their Kind. Open Road Media. p. 160. ISBN 978-1-5040-3149-3. Retrieved 12 October 2022.
  5. ^ Hansen, L.L.; Hansen, L.P. (2022). INTRO PENOLOGY & CORRECTIONS - 1E. Aspen Paralegal Series. Aspen Publishing. p. 435. ISBN 978-1-5438-4635-5. Retrieved 12 October 2022.
  6. ^ Riddle, J.E.; Loyd, S.M.; Branham, S.L.; Thomas, C. (2012). Nevada State Prison. Images of America (in Estonian). Arcadia Publishing. p. 63. ISBN 978-0-7385-8545-1. Retrieved 12 October 2022.
  7. ^ "Methods of Execution – Death Penalty Information Center". Archived from the original on 25 February 2011.
  8. ^ Catherine Merridale. Night of Stone: Death and Memory in Twentieth-Century Russia. Penguin Books, 2002 ISBN 0-14-200063-9 p. 200
  9. ^ Timothy J. Colton. Moscow: Governing the Socialist Metropolis. Belknap Press, 1998, ISBN 0-674-58749-9, p. 286 Archived 2019-09-27 at the Wayback Machine
  10. ^ Yevgenia Albats: KGB: The State Within a State. The secret police and its hold on Russia's past, present and future. (International Affairs, Vol. 72). London: Tauris, 1995, p. 101.
  11. ^ Tomasz Kizny, Dominique Roynette. La grande terreur en URSS 1937–1938. Lausanne: Éd. Noir sur Blanc, 2013, p. 236.
  12. ^ Henry Friedlander. The Origins of Nazi Genocide: From Euthanasia to the Final Solution. Chapel Hill: University of North Carolina Press, 1995, ISBN 978-0-8078-2208-1, p. 139.
  13. ^ "Revealed: The gas chamber horror of North Korea's gulag". February 2004. Archived from the original on 14 March 2018. Retrieved 25 January 2022.
  14. ^ Browning, Christopher (2005). The Origins of the Final Solution: The Evolution of Nazi Jewish Policy, September 1939 – March 1942. Arrow. ISBN 978-0-8032-5979-9.
  15. ^ a b c d "Gassing Operations". Holocaust Encyclopedia. United States Holocaust Memorial Museum. Archived from the original on 3 December 2017. Retrieved 30 November 2017.
  16. ^ Klee, Ernst (1983). Euthanasie im NS-Staat. Die Vernichtung lebensunwerten Lebens (in German). Frankfurt am Main: Fischer Taschenbuch Verlag. ISBN 978-3-596-24326-6.
  17. ^ Barnett, Antony (31 January 2004). "Revealed: the gas chamber horror of North Korea's gulag". The Guardian. Archived from the original on 24 May 2020. Retrieved 14 December 2016.
  18. ^ Video testimonials by former guards and prisoners at Camp 22 Archived 2007-10-24 at the Wayback Machine, where the experiments are said to have occurred, with Google Earth images Camp 22 and other camps
  19. ^ Olenka Frenkiel (30 January 2004). "Within prison walls". BBC News. Archived from the original on 23 June 2009. Retrieved 15 December 2009.
  20. ^ a b c Černevičiūtė, Sigita (8 April 2014). "Dujų kamera prieškario Lietuvoje 1937–1940 metais". (in Lithuanian). 15 min (republished from Naujasis Židinys-Aidai). Archived from the original on 27 November 2016. Retrieved 26 November 2016.
  21. ^ Zhirnov, Yevgeny (11 September 2009). "По пути следования к месту исполнения приговоров отравлялись газом". p. 56. Archived from the original on 10 December 2019. Retrieved 8 March 2016 – via Kommersant.
  22. ^ "Человек в кожаном фартуке". Archived from the original on 10 July 2015.
  23. ^ "Descriptions of Execution Methods: Gas Chamber". Death Penalty Information Center. 2010. Archived from the original on 12 November 2010. Retrieved 3 November 2010.
  24. ^ "Race in the Death House". Time. 25 March 1957. Archived from the original on 30 March 2008. Retrieved 14 November 2007.
  25. ^ "Execution Database | Death Penalty Information Center". Death Penalty Information Center. Archived from the original on 4 September 2021. Retrieved 4 September 2021.
  26. ^ a b c "German executed in Arizona, legal challenge fails". CNN. 4 March 1999. Archived from the original on 11 October 2008.
  27. ^ "Some examples of post-Furman botched executions". Death Penalty Information Center. 24 May 2007. Archived from the original on 22 November 2007.
  28. ^ Weil, Elizabeth (11 February 2007). "The needle and the damage done". The New York Times. Archived from the original on 21 April 2017.
  29. ^ Fierro, Ruiz, Harris v. Gomez, 77 f.3d 301, 309 (U.S. 9th Circuit 1996).
  30. ^ "Fierro v. Terhune, 147 F.3d 1158 | Casetext Search + Citator". Retrieved 9 February 2024.
  31. ^ "Methods of Execution". Death Penalty Information Center. Retrieved 6 February 2024.
  32. ^ "State-by-State Execution Protocols". Death Penalty Information Center. Retrieved 6 February 2024.
  33. ^ "Agriculture and Markets Law § 374". Archived from the original on 10 December 2019. Retrieved 31 January 2012.
  34. ^ Handbook of Death and Dying by Clifton D. Bryant – Page 499
  35. ^ "The Death Penalty's Future?". 31 March 2015. Archived from the original on 10 July 2015. Retrieved 9 July 2015. fourth paragraph
  36. ^ "The History Channel" – Modern Marvels (gas chamber) Archived 2015-07-09 at the Wayback Machine
  37. ^ "Reprieve telephone call comes as Burton Abbott is executed".
  38. ^ "In 1957, He Was Executed for Murder—But Was He a Victim of Circumstance?". 4 August 2015.
  39. ^ "Race in the Death House". TIME. 25 March 1957. Archived from the original on 30 March 2008. Retrieved 4 August 2022.
  40. ^ "Followimng moved for Wednesday PMS and is now available for AMs TODay's TOPIC: Ninth Reprieve". Associated Press.
  41. ^ "Gas chamber | execution device". Archived from the original on 28 June 2015. Retrieved 3 July 2015. second paragraph
  42. ^ "Execution by gas in Md. to end next week Killer Hunt's death will be last by method". The Baltimore Sun. 22 June 1997. Archived from the original on 5 July 2015.
  43. ^ Encyclopedia of Capital Punishment in the United States, 2d ed.  by Louis J. Palmer, Jr.  (page 319)
  44. ^ The Death Penalty As Cruel Treatment And Torture  by William Schabas  (page 194)
  45. ^ "Descriptions of Execution Methods". Death Penalty Information Center. Archived from the original on 2 February 2015. Retrieved 2 February 2015.
  46. ^ "HAZARDS OF INERT GASES AND OXYGEN DEPLETION". Singapore: Asia Industrial Gases Association.
  47. ^ "Oklahoma Gov. Mary Fallin signs bill allowing nitrogen asphyxiation as alternative execution method". Archived from the original on 29 March 2016.
  48. ^ Mark Berman (18 March 2018). "Oklahoma says it will begin using nitrogen for all executions in an unprecedented move". Washington Post. Archived from the original on 31 May 2020. Retrieved 10 August 2018.
  49. ^ "Oklahoma Attorney general says state will resume executions". New York Post. Archived from the original on 9 March 2021. Retrieved 22 March 2020.
  50. ^ "Alabama inmate Alan Eugene Miller granted stay of execution". 20 September 2022. Retrieved 6 October 2022.
  51. ^ Betts, Anna; Bogel-Burroughs, Nicholas (25 January 2024). "The Alabama Execution Case: What We Know". The New York Times. ISSN 0362-4331. Retrieved 26 January 2024.