It resulted in the highest known exposure to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) in residential populations[1] which gave rise to numerous scientific studies and standardized industrial safety regulations. The EU industrial safety regulations are known as the Seveso II Directive. The Seveso disaster was so named because Seveso, with a population of 17,000 in 1976, was the community most affected. Other affected neighbouring communities were Meda (19,000), Desio (33,000), Cesano Maderno (34,000) and to a lesser extent Barlassina (6,000) and Bovisio-Masciago (11,000).[2] The industrial plant, located in Meda, was owned by the company ICMESA (Industrie Chimiche Meda Società Azionaria), a subsidiary of Givaudan which in turn was a subsidiary of Hoffmann-La Roche (Roche Group). The factory building had been built many years earlier and the local population did not perceive it as a potential source of danger. Moreover, although several exposures of populations to dioxins had occurred before, mostly in industrial accidents, they were of a more limited scale.