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Agent Orange

Agent Orange was the US Army's code name for an herbicide used widely by the United States during the Vietnam War between 1961 and 1970. Other code-named herbicides used by the US Army in moderate to large quantities during this timeframe include Agent Blue (cacodylic acid), Agent White (4:1 mixture of 2,4-D and picloram[?]), Agent Purple, and Agent Pink. Their names were derived from the color of the stripes on the barrels used to transport them.

Agent Orange was found to have toxic dioxin breakdown byproducts which have been credited for causing health disorders and birth defects in both the Vietnamese population and U.S. war veterans. It has also been found to have carcinogenic properties.

The official military purpose of the herbicides was to remove the leaves of trees to deny the Viet Cong cover. However, an April 2003 report paid for by the National Academy of Sciences concluded that during the Vietnam War, 3,181 villages were sprayed directly with herbicides. Between 2.1 and 4.8 million people "would have been present during the spraying." Furthermore, many U.S. military personnel were also sprayed or came in contact with herbicides in recently sprayed areas.

The study was originally undertaken for the U.S. military to get a better count of how many veretans served in sprayed areas. Researchers were given accesses to military records and Air Force operational folders previously not studied.

The re-estimate made by the report places the 1961 to 1971 volume of herbicides sprayed between 1961 and 1971 to a level 7,131,907 liters more than an "uncorrected" estimate published in 1974 and 9.4 million more liters than a 1974 "corrected" inventory.

It was produced under contract for the Army by Diamond Shamrock, Dow, Hercules, Monsanto, T-H Agricultural & Nutrition, Thompson Chemicals, and Uniroyal. About 75 million liters of the agent were used during the course of the Vietnam War.

Agent Orange was a roughly 1:1 mixture of the herbicides 2,4-D (2,4-dichlorophenoxyacetic acid) and 2,4,5-T (2,4,5-trichlorophenoxyacetic acid). These herbicides were developed during the 1940s for use in controlling broad-leaf plants. First introduced in 1947, they rapidly gained acceptance, and their use was considered an integral agricultural practice by the middle of the 1950s.

Although Agent Orange as a military defoliant was discontinued in 1971, both 2,4-D and 2,4,5-T continue to be widely used independently as effective herbicides.