Rainbow Herbicides

Who made Agent Orange, what they and the government knew, and what the courts did and did not decide

Between 1962 and 1971 the U.S. Air Force sprayed about 19 million gallons of herbicides over South Vietnam, 11 to 12 million of them Agent Orange. Seven U.S. companies made over 99% of the Orange, and it carried a dioxin. In 1984 they paid $180 million to a class of Vietnam veterans and families, denying any liability. Vietnamese plaintiffs sued in 2004; courts dismissed their suit on the law, and the Supreme Court declined review in 2009. Since 1991 U.S. law has presumed some illnesses in Vietnam veterans to be service-connected, and since 2012 the U.S. has paid to clean two Vietnamese air bases, while denying any legal duty to do so. What Agent Orange caused, and who owes what, is still argued.

Nearly every line here comes from court opinions, the Air Force’s own history, Congress’s research service, and the words of veterans and Vietnamese people as courts, officials and reporters recorded them. Where counts differ, the story says who counted. The makers and the government each get their own say. A court’s reading of the evidence, a settlement and an allegation are told as what they are, not as findings of guilt.

1970

Who says they were hurt. Dr. Phan Thi Phi Phi ran a mobile hospital in sprayed Quang Nam and Quang Ngai from 1966 to 1971. Dr. Duong Quynh Hoa was told in Tay Ninh to cover her head with plastic bags when aircraft sprayed; in 1999 a test found “relatively high levels of dioxin in her blood.” Both sued in 2004, and the court recorded their accounts as allegations. Paul Reutershan, a U.S. veteran, filed the 1978 suit that began the American litigation; he is now deceased. Neither suit reached a verdict on what caused anyone’s illness.

John F. Kennedy

30 Nov 1961

The decision. Herbicides had been used in Vietnam since 1961 “at the request of the South Vietnamese government.” Deputy Defense Secretary Roswell Gilpatric put the Pentagon’s case to President Kennedy. Secretary of State Dean Rusk agreed, and warned of a Communist “germ warfare” campaign. On 30 November 1961 Kennedy approved a program starting with clearing key routes, with food denial only if resettlement and alternative food were in place. South Vietnamese consent and mission-by-mission U.S. approval were required.

Sep 1962

Ranch Hand. Mixtures were named for the color band on the barrel: Orange, White, Blue. The Air Force’s Operation Ranch Hand began in 1962. Its aims, in the Second Circuit’s words, were to strip cover and “to destroy crops to deprive them of food.” Policy was to spray “only in areas remote from population”; Stellman’s data show 3,181 hamlets sprayed directly, with at least 2.1 million, perhaps 4.8 million, people present. The Air Force history counts 18 million gallons over a fifth of the jungles and 36% of the mangroves. Other counts run 17.7 to 20.3 million gallons.

Mar 1967

Seven makers. Dow, Monsanto, Hercules, Diamond Shamrock, Uniroyal, Thompson Chemical and T.H. Agriculture & Nutrition. Each drum carried an orange stripe and a contract number but no warning; in Vietnam the drums were mixed, so no one can trace whose Orange reached whom. Dioxin ran under 1 part per million in some makers’ product and over 10 in one, on one court’s reading. The makers say they were compelled: in March 1967 Commerce invoked the Defense Production Act, which “essentially commandeered all of the Defendants’ capacity.” The Supreme Court’s 1996 summary says the government also “had superior knowledge of the hazards.”

Mar 1965

What the makers knew. In 1952 the Army learned of a 1949 accident at Monsanto’s plant at Nitro, West Virginia. Weinstein wrote that, reading the evidence most favorably to the veterans, a jury could find the makers had long known that dioxin “could develop chloracne, liver damage and other diseases” in factory workers, and that Dow knew by 1965 it could be hazardous at 1 part per million. Dow called a meeting that March; Monsanto was invited and did not attend. Dow and others, he wrote, “expressed fear” the government “might intervene in a way disastrous to the entire herbicide industry.” Evidence suggested Dow and Hercules cut dioxin below 1 ppm, while Monsanto’s and Diamond Shamrock’s stayed higher.

United States government

9 May 1963

What the government knew. In 1984 Weinstein sampled the evidence only to ask whether the makers could make a first case for the contractor defense; it “indicates that defendants would have been able to make out a prima facie case.” It showed Army chemical staff briefing the President’s Science Advisory Committee on 9 May 1963, and Edgewood scientists aware of dioxin before 1959. The government knew of hazards to workers “in large concentrations.” But the government and the veterans argued it did not learn what the makers knew at 1 ppm until 1970. A committee member said he did not tell President Johnson in 1965 because he did not think the threat serious.

10 May 2021

The makers’ answer. Dow says the makers “were compelled by the U.S. government to produce Agent Orange” and that decades of study “have not established a causal link to any diseases, birth defects or other transgenerational effects.” Monsanto says the former company was “one of nine wartime government contractors,” that “The government set the specifications,” and that it “determined when, where and how it was used.” Bayer, which owns Monsanto, argued in France that the makers “could not be held responsible for the use that the American military made of their product.” We found no statement of their own from Hercules, Diamond Shamrock or Uniroyal.

U.S. Department of Justice

10 May 1984

The government’s answer. Veterans could not sue it: the Second Circuit in 1987 affirmed dismissal of their suits against the United States. In 1984 the government told the court it spent some $70 million a year treating veterans who claim exposure, “even though causality has not been shown,” and it declined to join settlement talks. The Justice Department said it would fight the makers’ claim that the government should pay; in 1996 the Supreme Court held the makers could not recover. The Congressional Research Service says the Reagan administration “repeatedly expressed a skepticism” about veterans’ claims. In 2005 the government filed a Statement of Interest for the makers.

U.S. Congress

1975

Chemical warfare? Officials feared “charges of barbarism for waging a form of chemical warfare.” In 1969 the U.S. argued herbicides, “unknown in 1925,” were outside the Geneva Protocol, and voted against a UN resolution saying otherwise. In 1970 the Senate rejected, 62 to 22, a ban on military use of anti-plant chemicals. The Protocol took force for the U.S. in 1975, when President Ford renounced “first use of herbicides in war” as national policy. In 2005 Weinstein held that spraying “violated no rights of plaintiffs under international law.” In 2008 the Second Circuit found no “norm prohibiting the wartime use of Agent Orange” of the required precision. Neither ruled on whether it harmed anyone.

15 Apr 1970

The end of Orange. A government study of June 1966 found “teratogenicity (birth defects) in mice”; the government analysed it further in early 1969 “but it did not restrict the ongoing herbicide program in Vietnam.” In April 1970 the U.S. banned 2,4,5-T from most uses at home. The Pentagon’s research director, John Foster, urged suspending Orange in Vietnam; the Joint Chiefs’ chairman wanted limits instead. On 15 April the Department of Defense chose suspension. Spraying of other herbicides went on; the last Ranch Hand herbicide mission flew on 7 January 1971.

7 May 1984

The settlement. On 7 May 1984, the day jury selection was to begin, seven makers settled with a class of American, Australian and New Zealand veterans and their families. Paragraph 10 of the agreement says it is no “admission or concession by any defendant of any liability or wrongdoing whatsoever,” which each denies, and no concession by the plaintiffs of “any lack of merit in their claims.” A fund indemnified the makers against state-court judgments up to $10 million. Both sides reserved their claims against the United States. A settlement is not a finding of guilt, and not a finding against the veterans.

1984

At the hearings. The judge heard families across the country. One veteran backed the deal because it might pressure the Government: “It is not the chemical companies’ responsibility.” A former Army nurse called the allocation “triage”: “We don’t need your insignificant amount of money.” Another speaker said, “Somebody engaged in chemical warfare. Somebody violated international law.” The Justice Department “chose not to attend any of the Fairness Hearings.” The judge made no finding on complaints about the VA, thought it “highly unlikely” care was “uniformly bad,” and wrote, “Many do deserve better of their country.”

21 Apr 1987

The doubt. In 1984 the judge wrote that a single veteran’s case “probably would have to be dismissed,” since present knowledge could not show, apart from chloracne, that Agent Orange rather than something else injured a particular veteran. As a class action he would probably have let it go on. In 1987 the Second Circuit approved the settlement as “essentially a payment of nuisance value” for 240,000 claimants. On the opt-outs it held the makers breached no duty to inform: the government had as much knowledge “then relating largely to chloracne and a rare liver disease,” and “the weight of present scientific evidence” did not establish injury. That second ground rests on 1987 science.

6 Feb 1991

The Act. In 1989 a federal court in the Nehmer case struck down the VA’s rule allowing service connection only for chloracne. Admiral Zumwalt, then the Secretary’s special assistant, wrote that as Commander, U.S. Naval Forces, Vietnam, he knew Agent Orange “was frequently used on unrecorded missions”; charged “political interference” in a CDC study; found it “at least as likely as not” that Agent Orange was linked to a long list of illnesses, birth defects among them; and said the VA’s advisory committee had “not acted with impartiality.” These are his charges. On 6 February 1991 the Agent Orange Act became law: three diseases presumed service-connected, and an outside body to review the evidence.

2018

What the Academy found. The Act sent the evidence to a scientific panel. By its eleventh report, in 2018, “sufficient evidence” covered seven conditions: those five, and hypertension and MGUS. It could not agree whether type 2 diabetes belongs there or one rung lower. Birth defects in veterans’ children are “inadequate or insufficient”: no conclusion either way, though U.S. law still covers spina bifida. In 1994 the panel said veterans as a group had “substantially lower exposure” than many workers “although definitive data are lacking”; Ranch Hand airmen were “an exception,” and others were likely exposed “at levels associated with health effects.” It says its findings concern populations, not any one person’s illness. Dow’s “causal link” and the panel’s “association” are different tests.

2012

Vietnam’s case. Vietnam argues that the exposed and their children and grandchildren have “an unusually high level of birth defects and/or health problems.” A Vietnamese ministry counts over 365,000 people. Studies cited by the Congressional Research Service found blood dioxin “nearly six times higher” in people from sprayed areas, and Da Nang residents “more than 100 times globally acceptable levels.” Others dispute the link: one study found soils “generally at or below background levels”; a 2003 State Department dispatch said Vietnam would not accept “internationally recognized scientific methods.” Vietnam said U.S. officials were told to block the studies; the U.S. “unilaterally terminated” them in 2005. Exposure is not proof of harm, and no large-scale study has settled cause.

2004

The Vietnamese suit. In 2004 the Association and individual Vietnamese people, among them Dr. Duong Quynh Hoa, sued Dow, Monsanto and other makers in Brooklyn. They charged war crimes, including use of poison and chemical agents, and sought damages, cleanup and the makers’ profits. The Association said it spoke for a class of some four million. The makers argued the claims failed under international law, were barred by the contractor defense, and that the plaintiffs lacked standing. The judge ruled for the plaintiffs on several points, including standing, whether the courts could hear it at all, and time limits. The U.S. government sided with the makers.

U.S. Supreme Court

10 Mar 2005

Dismissed. On 10 March 2005 Judge Weinstein dismissed the suit. The domestic claims failed on the contractor defense. On international law he treated Agent Orange “for the purposes of this 12(b)(6) motion” as a herbicide, not a poison, while allowing it “may have caused some results analogous to those of poisons.” The Second Circuit affirmed in 2008: Agent Orange “was used as a defoliant and not as a poison designed for or targeting human populations.” The Supreme Court declined review on 2 March 2009, in this case and in the U.S. veterans’ last suits. On cause, the judge wrote only that “there is no need to pursue this issue at this time.”

22 Aug 2024

Tran To Nga. A French-Vietnamese former reporter sued 14 firms in France in 2014. The Évry court in 2021 and the Paris Court of Appeal in 2024 held the companies immune, saying they acted “on the orders” of the U.S. government in “a sovereign act.” Nga says she has type 2 diabetes and a rare insulin allergy, had tuberculosis twice and cancer, and lost a daughter to a heart malformation; she links these to Agent Orange. “We will continue to prove to the world that justice is on our side,” she said in 2024. AFP says only military veterans have won compensation. On 8 July 2026 the Court of Cassation sent her appeal to its full court.

Nov 2018

The cleanup. At Da Nang over 90,000 cubic meters of soil were treated, and the cleaned land went to the airport’s expansion. Bien Hoa holds about 500,000 cubic meters. Vietnamese reports put its cost at $390 million in 2018 and $450 million in 2023; funding stood at $430 million in January 2025. U.S. aid cuts froze the work for about a week in 2025; the State Department said three contracts were “active and running.” We read nothing newer. The U.S. “does not recognize any legal liability.” The 1995 claims deal “makes no provision for reparations” for herbicides, and aid is to be “a humanitarian act, and not an admission of culpability.”

What this story could not read: any statement of its own from Hercules, Diamond Shamrock or Uniroyal; the makers’ internal files beyond what judges quoted; Bien Hoa after the March 2025 reports; and the Court of Cassation’s final ruling in The French Agent Orange suit. The 1984 judge’s account of what the makers and the government knew was written to test a settlement, not after a trial. Dioxin and gallon totals differ by who counted and what they assumed; the scenes say so.

Pictures, from Wikimedia Commons: John F. Kennedy, Cecil W. Stoughton, Public domain; United States government, Martin Falbisoner, CC BY-SA 3.0; U.S. Department of Justice, APK, CC BY 4.0; U.S. Congress, Martin Falbisoner, CC BY-SA 3.0; U.S. Supreme Court, UpstateNYer, CC BY-SA 3.0.

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