Zyklon B

Zyklon B was the tradename of a pesticide. It consisted of little pellets or discs of wood pulp or diatomaceous earth which were impregnated with hydrocyanic acid, a stabilizer and a warning odorant/irritant. The pellets evolved hydrogen cyanide as a gas once removed from their air-tight containers. It is almost universally believed that the pesticide was used by Nazi Germany in the Holocaust gas chambers of the Auschwitz Birkenau and Majdanek extermination camps.

Zyklon B was used in the concentration camps initially for delousing to control typhus. In September 1941, the first experiments were performed in Auschwitz I to test the killing of humans with the poison. Zyklon B was provided by the German companies 'Degesch (Deutsche Gesellschaft für Schädlingsbekämpfung GmbH) and Tesch und Stabenow, under license from I.G. Farben, which held the patent. The Nazis ordered Degesch to produce Zyklon B without the warning chemical, a breach of German law. Post-war two directors of Tesch were tried by a British military court and were executed for their part in supplying the chemical.

The use of the word zyklon (German for cyclone) continues to prompt angry reactions from Jewish groups. In 2002 both Bosch Siemens Hausgeraete and Umbro were forced to withdraw from attempts to use or trademark the term for their products.

Zyklon A was also a pesticide, using methyl cyanoformate as the active agent. Its manufacture was banned under the Treaty of Versailles as it could be an intermediate in poison gas production.