Interessengemeinschaft Farbenindustrie AG, commonly known as IG Farben, was a German chemical and pharmaceutical conglomerate formed in 1925 from a merger of six chemical companies—BASF, Bayer, Hoechst, Agfa, Griesheim-Elektron, and Weiler-ter Meer. The company was once the largest company in Europe and the largest pharmaceutical company in the world, but the company is most known for being the main manufacturer of Zyklon B, a cyanide-based pesticide used by Nazi Germany during the Holocaust. After World War II ended, the company was seized by the Allies and divided back into its constituent companies.
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