Agent Orange was a chemical herbicide used from 1961 to 1971 by the U.S. military in the then
Republic of Vietnam (a.k.a.—South Vietnam) and portions of the then Democratic Republic of
Vietnam (a.k.a.—North Vietnam) to deny their military enemy cover in Vietnam’s dense foliage.47
An approximately 50-50 mix of two chemicals—2,4,-D (2,4, dichlorophenoxyacetic acid) and
2,4,5-T (2,4,5 trichlorophenoxyacetic acid)—Agent Orange derived its name from the orange
band painted on the side of the 55-gallon drums in which the herbicide was delivered. Agent
Orange was manufactured under Department of Defense (DOD) contracts for military-use in
Vietnam by several companies, including Diamond Shamrock Corporation, Dow Chemical
Company, Hercules Inc., Monsanto Company, T-H Agricultural & Nutrition Company, Thompson
Chemicals Corporation, and Uniroyal Inc.
Agent Orange was one of 15 herbicides used during the Vietnam War, principally as part of
Operation Ranch Hand, the key component of the U.S. military’s overall herbicide program,
Operation Trail Dust.48 Other herbicides used in Vietnam included Agent Blue, Agent Green,
Agent Orange II (a.k.a. Super Orange), Agent Pink, Agent Purple, Agent White, Bromacil,
Dalapon, Dinoxol, Diquat, Diuron, Monuron, Tandex, and Trinoxol. However, Agent Orange was
the most extensively used herbicide during the war.
A contaminant of the manufacture of Agent Orange (as well as Agents Pink and Purple) was
2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), a dioxin thought to be responsible for most of the
medical problems associated with exposure to Agent Orange. Because TCDD was an unwanted
byproduct, its concentration varied by production run, manufacturer, and the proportion of
2,4,5-T in the formulation. A 1978 General Accounting Office (GAO, now known as Government
Accountability Office) report indicated that a 1971 DOD analysis of its remaining Agent O