Section A.

The Truth about Agent Orange and other Herbicides in Thailand during the Vietnam War


A. The legal framework of the Vietnam presumptions.

In 1991, Congress passed the Agent Orange Act, which mandated that certain diseases associated with exposure to herbicide agents, including chloracne and non-Hodgkin’s lymphoma, be presumed service-connected.  Section 1116 of title 38 of the United States Code and 38 C.F.R. § 3.307 and 3.309 provide the legal authority and framework for awarding benefits to Vietnam veterans with herbicide agent-related diseases.  When Congress enacted this law, it stated, “the term ‘herbicide agent’ means a chemical in an herbicide used in support of the United States and allied military operations in the Republic of Vietnam during the period beginning on January 9, 1962, and ending on May 7, 1975.”  38 U.S.C. § 1116.  Figure 1.1 lists (and Figure 1.2 illustrates) the chemical composition of each of the herbicide agents as well as the time period in which they were used in Vietnam.
38 U.S.C. § 1116 is a dual-function statute titled:  “Presumptions of service connection for diseases associated with exposure to certain herbicide agents; presumption of exposure for veterans who served in the Republic of Vietnam.”

Figure 1.1 – Herbicides and their agents used in Vietnam during the Vietnam War

Code/NamePrimary Agents in HerbicideTime Used in Vietnam
Pink60% n-butyl ester of 2,4,5-T
40% isobutyl ester of 2,4,5-T
1962-1965
Green100% n-butyl ester of 2,4,5-T1962-1965
Pink-Green mixture80% n-butyl ester of 2,4,5-T
20% isobutyl ester of 2,4,5-T
1962-1965
Purple50% n-butyl ester of 2,4-D
30% n-butyl ester of 2,4,5-T
20% isobutyl ester of 2,4,5-T
1962-1965
Blue100% sodium salt of cacodylic acid1962-1971
Orange50% n-butyl ester of 2,4-D
50% n-butyl ester of 2,4,5-T
1965 and after
Orange II50% n-butyl ester of 2,4-D
50% isooctyl ester of 2,4,5-T
1965 and after
White80% triisopropanolamine salt of 2,4-D
20% triisopropanolamine salt of picloram
1965 and after

Figure 1.2 – Visual representation of Figure 1.1

Herbicides and their agents used in Vietnam during the Vietnam War

Herbicides and their Agents

VA followed suit by drafting regulations to coincide with the statute by defining the term as follows: “‘herbicide agent’ means a chemical in an herbicide used in support of the United States and allied military operations in the Republic of Vietnam[,] . . . specifically: 2,4-D; 2,4,5-T and its contaminant TCDD; cacodylic acid; and picloram.” 38 C.F.R. § 3.307(a)(6)(i). The important element of a successful claim for disability compensation based on exposure to herbicides used outside of Vietnam is demonstrating that the agent contained in the herbicide in one of those listed above.