Gas chamber Gas chamber 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. 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 and continue to be a legal execution method in three states. During the Holocaust, large-scale gas chambers designed for mass killing were used by Nazi Germany as part of their genocide program.
Gas chamber 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 killings at the Auschwitz and Majdanek camps. Up to 6000 victims were gassed with Zyklon-B each day at Auschwitz. Most extermination camp gas chambers were dismantled or destroyed in the last months of the World War II as Soviet troops approached, except for those at Dachau, Sachsenhausen and Majdanek. One destroyed gas chamber at Auschwitz was reconstructed