A gas chamber is an apparatus for killing humans or animals with gas, consisting of a sealed chamber into which a poisonous or asphyxiant gas is introduced. The most commonly used poisonous agent is hydrogen cyanide; carbon dioxide and carbon monoxide have also been used. Gas chambers were used as a method of execution for condemned prisoners in the United States beginning in the 1920s. During the Holocaust, large-scale gas chambers designed for mass killing were used by Nazi Germany as part of their genocide program, and also by the Independent State of Croatia at the Jasenovac concentration camp.^[1] The use of gas chambers has also been reported in North Korea.^[2]

United States[link]

Gas chamber usage in the United States.

  Secondary method only

  Previously used, but not today

  Never used gas chamber

Post-Furman uses by state and numbers

Gas chambers have been used for capital punishment in the United States to execute criminals, especially convicted murderers. 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 Gee's death sentence.^[3] In 1957, Burton Abbott was executed as the governor of California, Goodwin J. Knight, was on the telephone to stay the execution.^[4] Since the restoration of the death penalty in the United States in 1976, eleven executions by gas chamber have been conducted.^[5] 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 eight 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. 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."^[6]

During the April 6, 1992, execution of Donald 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.^[7] Following Harding's execution, Arizona voted that all persons condemned after November 1992 would be executed by lethal injection.^[5]

Following the execution of Robert Alton Harris, a federal court declared that "execution by lethal gas under the California protocol is unconstitutionally cruel and unusual."^[8] 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 2010, 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 9th U.S. Circuit Court of Appeals had ruled that he could not be executed by gas chamber, but the decision was overturned by the U.S. Supreme Court.^[5] The gas chamber was formerly used in Colorado, Nevada, New Mexico, North Carolina and Oregon. Six states, Arizona, California, Maryland, Mississippi, Missouri 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.^[9] In October 2010, New York governor David Paterson signed a bill rendering gas chambers illegal for use by humane societies and other animal shelters.^[10]

Method of use[link]

Using hydrogen cyanide[link]

This unreferenced section requires citations to ensure verifiability.

The former gas chamber in 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.

When executions by gas chambers are conducted in the United States, the general protocol is as follows. First, the executioner will place a quantity of potassium cyanide (KCN) pellets into a compartment directly below the chair in the chamber. The condemned person is then brought into the chamber and strapped into the chair, and the airtight chamber is sealed. At this point the executioner will pour a quantity of concentrated sulfuric acid (H₂SO₄) down a tube that leads to a small holding tank directly below the compartment containing the cyanide pellets. The curtain is then opened, allowing the witnesses to observe the inside of the chamber. The prison warden then asks the condemned individual if he or she wishes to make a final statement. Following this, the executioner(s) throws a switch/lever to cause the cyanide pellets to drop into the sulfuric acid, initiating a chemical reaction that generates hydrogen cyanide (HCN) gas:

2KCN_(s) + H₂SO_4(aq) → 2HCN_(g) + K₂SO_4(aq)

The gas is visible to the condemned, and he/she is advised to take several deep breaths to speed unconsciousness in order to prevent unnecessary suffering. Accordingly, execution by gas chamber is especially unpleasant for the witnesses to the execution due to the physical responses exhibited by the condemned during the process of dying. These responses can be violent, and can include convulsions and excessive drooling.

Following the execution, the chamber is purged of the gas through special scrubbers, and must be neutralized with anhydrous ammonia (NH₃) before it can be opened. Guards wearing oxygen masks remove the body from the chamber. Finally, the prison doctor examines the individual in order to officially declare that he or she is dead and release the body to the next of kin.

One of the problems with the gas chamber is the inherent danger of dealing with such a toxic gas. Anhydrous ammonia is used to cleanse the chamber after cyanide gas has been used:

HCN + NH₃ → NH₄⁺ + CN⁻

The anhydrous ammonia used to clean the chamber afterwards, and the contaminated acid that must be drained and disposed of, are both very poisonous.

Excluding all oxygen[link]

Nitrogen gas or oxygen-depleted air has been considered for human execution, as it can induce nitrogen asphyxiation. It has not been used to date.^{[citation needed]}

Nazi Germany[link]

Interior of Majdanek gas chamber, showing Prussian blue residue

Gas chambers were used in the Third Reich as part of the "public euthanasia program" aimed at eliminating physically and intellectually disabled people and political undesirables in the 1930s and 1940s. In June 1942 many hundreds of prisoners of Neuengamme concentration camp, amongst which 45 Dutch communists, were gassed in Bernburg. At that time, the preferred gas was carbon monoxide, often provided by the exhaust gas of gasoline-powered cars, trucks or army tanks.^[11]

Some Nazi extermination camps including Auschwitz used hydrogen cyanide in the form of Zyklon B.

During the Holocaust, gas chambers were designed to accept large groups as part of the Nazi policy of genocide against the Jews. Nazis also targeted the Romani people, homosexuals, physically and mentally disabled, intellectuals and the clergy. According to Nizkor Project (Hebrew: נִזְכּוֹר‎), on September 3, 1941, 600 Soviet POWs were gassed with Zyklon B at Auschwitz camp I; this was the first experiment with the gas at Auschwitz.^[12] According to a website run by Jürgen Langowski, an anti-Nazi German activist, Carbon monoxide was also used in large purpose-built gas chambers, like chambers in Treblinka extermination camp. The gas was in exhaust gas from internal combustion engines (detailed in the Gerstein Report).^[13]

Gas chamber at the Stutthof concentration camp.

Gas chambers in vans, concentration camps, and extermination camps were used to kill several million people between 1941 and 1945. Some stationary gas chambers could kill 2,000 people at once.^[14] The use of gas chambers during the Holocaust was attested to by several sources including the Vrba-Wetzler report and testimony from Rudolf Höss, Commandant of the Auschwitz concentration camp, and other German soldiers.^[15][16][17]

The gas chambers were dismantled or destroyed^[18] when Soviet troops got close, except at Dachau, Sachsenhausen, and Majdanek. The gas chamber at Auschwitz I was reconstructed after the war as a memorial, but without a door in its doorway and without the wall that originally separated the gas chamber from a washroom. The door that had been added when the gas chamber was converted into an air raid shelter was left intact.^[12]

Gaswagen[link]

Execution by exhaust gas was performed in specially modified vans, known as gaswagen (variously translated as "gas wagon", "gas van", or "gas car").^[19]

Napoleonic France[link]

In his book, Le Crime de Napoléon, French historian Claude Ribbe has claimed that in the early 19th century, Napoleon used poison gas to put down slave rebellions in Haiti and Guadeloupe. Based on accounts left by French officers, he alleges that enclosed spaces including the holds of ships were used as makeshift gas chambers where sulfur dioxide gas (probably generated by burning sulfur, which would have been readily available from volcanoes in the area) was used to execute up to 100,000 rebellious slaves. These claims remain controversial.^[20]

Livestock[link]

Gas chambers have also been used for animal euthanasia, using carbon monoxide as the lethal agent. Sometimes a box filled with anesthetic gas is used to anesthetize small animals for surgery or euthanasia.

References[link]