Inert Zyklon B, spent Gypsum pellets, from Majdanek concentration camp

Inert, Gypsum-based, spent Zyklon-B pellets, recovered outside a crematorium at Majdanek killing center in Poland, following the liberation of the camp by the Soviet army in July 1944. Developed and patented in 1924 by Deutsche Gesellschaft für Schädlingsbekämpfung mbH (German Corporation for Pest Control, a subsidiary of Degussa), Zyklon-B was originally produced as a pesticide and rodenticide. It was created by infusing liquid hydrogen cyanide (also known as prussic acid) into one of three carriers: wood fiber disks, diatomaceous earth (trade name: Diagriess), or gypsum (calcium sulfate, also known as Erco) pellets. The product would then be sealed into metal canisters and shipped to the camps. Upon opening the can, the hydrogen cyanide would begin to evaporate into a breathable gas, so it was most effective if released into a sealed room. Heat and humidity affected the rate of evaporation, so hot air would be blown into the sealed gas chamber to speed up the killing process. The SS administration of Majdanek placed orders with the firm, Tesch & Stabenow, who distributed pellets manufactured by Dessauer Werke für Zucker und Chemische Industrie (Dessau Works for Sugar and Chemical Industry). Zyklon-B was used as a delousing agent, before its effectiveness for mass executions was discovered at the Auschwitz main camp in September 1941. It then held dual roles of exterminating parasitic insects and people considered inferior by Nazi eugenics. The gas chambers at Majdanek were completed in October 1942 and continued operations until spring 1944, when the camp was evacuated. Between 80,000 and 110,000 people died or were killed at Majdanek. In March 1946, Bruno Tesch and Karl Weinbacher, the owner and deputy of Tesch & Stabenow, were tried in Hamburg by the British Military Court. They were found guilty and executed for supplying poison gas for the murder of prisoners. Following the war, Zyklon B continued to be produced and sold under other names.