hese studies, the active ingredient in the compound was isolated in 1957, and identified as dioxin. Subsequent research has indicated that dioxin is one of the most toxic substances ever created by man. At least 170 kilograms of dioxin were present in the substances used to defoliate areas of South Vietnam (Science 1197). The major producer of Agent Orange was the Dow Chemical Company, although the herbicide was also manufactured by Thomp-son Hayward Co., Uniroyal Inc., Diamond Shamrock Inc., and Monsanto (Los Angeles Times, part 1, 15).
The health hazards posed by the phenoxy herbicides has
been understood for many years, and was acknowledged by officials of Dow Chemical company before and during the period when Agent Orange was being supplied to the U.S. Military.
In confidential memos written by toxicology experts working with Dow, the harmful effects of dioxin to humans and animals were sketched out. A large spill of dioxin at Dow's Midland, Michigan plant caused severe health problems for employees causing Dow to hold an inter-company seminar on the toxicity of the chemical. In 1965, Dow's head of toxicology wrote a confidential letter to his superiors describing dioxin as "exceptionally toxic," but instead of recommending safeguards or further research, he went on simply to urge that the fact be kept in strict confidence (Time 17). Specifically, Dow had discovered that dioxin was ten times as toxic in humans as the nerve gas employed during World War I, and it was recommended that the level of dioxin present in Agent Orange be kept to no more than one part per million. There is some dispute as to whether the military was aware of the high toxicity of the chemical it was using in Vietnam. Dow maintained that the Defense Department knew of dioxin's health hazards, despite the fact that it kept its own findings secret. The Pentagon, however, claims that it bought Agent Orange on the grounds that it was supposed to be harmles...