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Veterans Law

The History of Agent Orange

Kaitlyn Degnan

August 21, 2018

Updated: February 16, 2024

CCK history of agent orange


The History of Agent Orange

What Are Agent Orange and Herbicide Agents?

Agent Orange is one of multiple rainbow herbicides, and it was infamously used in the Vietnam War as a defoliant to destroy enemy crops and clear foliage to increase visibility to prevent attacks by the enemy. The term “Agent Orange” came not from the appearance of the chemical itself, but from the identifying orange stripe emblazoned on the side of the massive drums in which it was stored.

However, Agent Orange was not the only herbicide used during the Vietnam War. The military used various “rainbow herbicides” which included Agent White, Agent Blue, and Agent Pink, among others. In their regulation regarding herbicide exposure, VA lists multiple herbicide agents considered as rainbow herbicides, such as cacodylic acid, picloram, along with 2,4-D and 2,4,5-T. Agent Blue contained cacodylic acid and arsenic, while Agent White was a mixture of picloram and 2,4-D. Agents Pink, Green, and Purple were made up of varying combinations of 2,4,5-T esters.

Agent Orange specifically is a 50/50 mixture of two kinds of herbicide agents: 2,4-D and 2,4,5-T. Agent Orange also contained the contaminant TCDD as a byproduct of its production.  TCDD, short for 2,3,7,8-Tetrachlorodibenzo-para-dioxin, is the most toxic of all the dioxins.

What Was Agent Orange Used For?

Agent Orange was used by the U.S. military during a number of conflicts throughout the ‘60s and ‘70s. In Vietnam, the Korean Demilitarized Zone, Thailand, and other bordering areas such as Cambodia and Laos, the military sprayed mass quantities of this defoliant chemical. The goal was to clear out foliage, depriving enemy fighters of a place to be concealed from view.

Thousands of U.S. soldiers fighting in the area were exposed to Agent Orange, and many later developed serious medical issues. The U.S. Department of Veterans Affairs (VA) has acknowledged an association between exposure to herbicides and a host of severe ailments. If you are a military veteran diagnosed with one of these conditions following Agent Orange exposure, you could be eligible for VA disability benefits.

When Was Agent Orange Used?

Agent Orange was used in a number of military operations during the 1960s and 1970s.  Though most commonly associated with Vietnam, the defoliant chemical played a role in several other conflicts and operations, including in Korea and Thailand.

VA Presumptive Locations

Veterans with qualifying service during the Vietnam era include veterans who served in:

  • The Republic of Vietnam(boots on the ground, Brown Water, and Blue Water Navy service) from January 9, 1962 to May 7, 1975;
  • Thailand, at any US or Thai base, from January 9, 1962 to June 30 1976, without regard to the Veteran’s MOS or where on base they were located;
  • Laos from December 1, 1965 to September 30, 1969;
  • Cambodia, specifically at Mimot or Krek, Kampong Cham Province from April 16, 1969 to April 30, 1969;
  • Guam or American Samoa or in the territorial waters thereof from January 9, 1962 to July 30, 1980;
  • Johnson Atoll or a ship that called at Johnston Atoll from January 1, 1972 to September 30, 1977.
  • The Korean Demilitarized Zone (DMZ) from September 1, 1967 to August 31, 1971.
  • C-123 aircraft from 1969 to 1986.

VA presumes service exposure for veteran with active military, naval, air, or space service in one of the above time periods and locations.  This means that if these veterans develop certain medical conditions VA acknowledges as associated with herbicide exposure, they will receive presumptive service connection.

VA Presumptive Conditions

If you were diagnosed with a medical condition linked to Agent Orange, you should have a straightforward path to receiving a grant of disability benefits.  The following are included on VA’s presumptive list:

  • AL Amyloidosis
  • Bladder Cancer
  • Chronic B-cell Leukemias
  • Chloracne
  • Diabetes Mellitus Type 2
  • Hodgkin's disease
  • Hypertension
  • Hypothyroidism
  • Ischemic Heart Disease
  • Monoclonal Gammopathy of Undetermined Significance
  • Multiple Myeloma
  • Non-Hodgkin's Lymphoma
  • Parkinson's Disease
  • Parkinson's-like Symptoms
  • Peripheral Neuropathy
  • Porphyria Cutanea Tarda
  • Prostate Cancer
  • Respiratory Cancer
  • Soft Tissue Sarcomas

Who Developed Agent Orange?

The two components of Agent Orange, 2,4-D and 2,4,5-T have been around since World War II.  Near the end of World War II, there was discussion of using herbicides in a tactical environment.  There was also discussion of using these herbicides during the Korean War.

When the Vietnam Era approached, the Army Chemical Corp began testing various combinations of herbicides at Fort Detrick.  The Advance Research Projects Agency (ARPA), now known as the Defense Advance Research Projects Agency (DARPA), was heavily involved in research regarding herbicides.

Were Herbicides Tested in the United States?

Herbicides were tested in the United States prior to the Vietnam War as early as the 1950s, as well as in the early years of the Vietnam War.  Herbicides were also tested in Thailand and Vietnam.  Several U.S. bases were used to test herbicides including Fort Gordon, Puerto Rico, and Hawaii.

Service members who tested these herbicides are also at risk of developing health problems.

Operation Ranch Hand and How Herbicides Were Sprayed

During the Vietnam War, herbicides including Agent Orange were sprayed in mainly four ways:

  1. C-123 aircraft were used to spray herbicides over the jungles of Vietnam during Operation Ranch Hand.  These C-123 aircraft were modified with tanks to carry the herbicides.
  2. Helicopters were used to spray smaller areas.
  3. Buffalo turbines were used to spray roadsides and perimeters.  Buffalo turbines are truck-mounted sprayers.
  4. Hand-held sprayers were also used as a method of spraying herbicides.

Operation Ranch Hand

Operation Ranch Hand was a U.S. military operation in which C-123 aircraft were used to spray herbicides over large swaths of jungle in Vietnam.  The operation spanned from 1962 to 1971 and involved spraying millions of gallons of herbicides, most notably Agent Orange.

VA recognizes that service members who worked on C-123 aircraft were exposed to Agent Orange through contact with the residue on the aircraft used in Operation Ranch Hand.

Herbicides After the Vietnam War & VA Disability for Exposure

The U.S. military stopped spraying herbicides out of C-123 aircraft in Vietnam in approximately 1971.  Although herbicides were no longer being used, there were still stores of the herbicide agents left over, including large stores in Vietnam and Gulf Port, Mississippi.  Eventually, these stockpiles were moved to Johnston Island in the Pacific Ocean around 1974.

The herbicides remained on Johnston Island until approximately 1977.  The herbicides, mainly Agent Orange, were then burned at sea.  However, Agent Blue could not be burned at sea due to its high concentration of arsenic.  Agent Blue was transported to Davis-Monthan Air Force Base where it was used to clear vegetation until the stores were used up.

Are There Records?

Following the Vietnam War, many veterans claimed that they were exposed to Agent Orange while they were stationed in Vietnam.  However, records of spraying, especially hand spraying, were poorly kept, leaving veterans without evidence to show that they were exposed.

Veterans Dioxin and Radiation Exposure Compensation Standards Act of 1984

The Veterans Dioxin and Radiation Exposure Compensation Standards Act of 1984 was enacted to address VA’s lack of regulations regarding claims for service connection based on veterans’ exposure to dioxin during their service in Vietnam.  The Act specifically addressed herbicides that contained dioxin, which, while not all the herbicides used in Vietnam contained, was a component of Agent Orange.

The Act instructed VA to study the herbicides and create regulations as to who could receive benefits and for which diseases they could receive benefits.  This was the first time Congress acted on legislation for herbicide exposure.

Nehmer v. Department of Veterans Affairs

In 1986, not long after the Veterans Dioxin and Radiation Exposure Compensation Standards Act was passed, a class action lawsuit was filed to challenge a VA regulation that stated that chloracne was the only disease that was scientifically linked to exposure to herbicides such as Agent Orange.

Part of the lawsuit Nehmer v. Department of Veterans Affairs included a claim that VA required a “cause and effect” relationship between a disease and Agent Orange exposure, when Congress intended VA to make its regulations based on a positive association between exposure and diseases.

The Court agreed that VA was using too high of a standard, and it invalidated VA’s regulation and instructed VA to re-adjudicate any claims that had been denied under the now invalid regulation.  The ruling is significant for veterans not only because more conditions were added to VA’s presumptive list, but also because it obligated VA to, when it adds a new condition to the list, identify all claims for that condition that were previously filed and/or denied, and re-adjudicate them.  This can result in veterans or their dependents being paid benefits retroactively to their original claim.

The Agent Orange Act of 1991 and VA’s Herbicide Regulations

Congress enacted the Agent Orange Act of 1991 which included many elements of the Nehmer case and was also meant to ease the burden on Vietnam veterans when it came to proving that their conditions were caused by their exposure to herbicides during their service in Vietnam.  The Act required VA to contract with the Institute of Medicine (IOM) every two years to determine if there was existing research that showed associations between herbicides and certain diseases.

When IOM would release its reports, it would classify diseases in different categories by levels of association.  Based on these classifications, VA would add diseases to its presumptive list.

The Act required VA to create a presumption of exposure which states that VA will presume that veterans who served in the Republic of Vietnam during the war were exposed to Agent Orange.  However, at that time, the presumption only included veterans who served “boots-on-the-ground” and those who were stationed aboard ships that navigated the inland waterways of Vietnam, called Brown Water veterans.

In addition to the presumption of exposure, the Agent Orange Act established presumptions for certain disabilities as related to herbicide exposure.  This led to VA’s creation of a presumption of service connection.

The presumption of service connection removes the requirement that veterans provide a medical nexus linking their condition to their military service.  Instead, at that time, if a veteran served in Vietnam between January 1, 1962 and May 7, 1975 and had a disease or condition associated with herbicide exposure, VA presumed that the veteran’s in-service exposure to herbicides caused their condition.

VA’s presumptive list has since expanded, and now includes 19 conditions, with two conditions recently added as part of the 2022 PACT Act.

PACT Act Adds Agent Orange Presumptive Locations and Conditions

Enacted on August 10, 2022, the Honoring Our Promise to Address Comprehensive Toxics (PACT) Act of 2021 expanded presumptions related to Agent Orange exposure to include veterans who served in Thailand, Cambodia, Laos, Guam, American Samoa, and at Johnston Atoll.  Specifically, the legislation amended 38 USC § 1116 to extend the presumption of herbicide exposure to service members with active military, naval, air, or space service in the following locations and time periods:

  • The Republic of Vietnam from January 9, 1962 to May 7, 1975;
  • Thailand, at any US or Thai base, from January 9, 1962 to June 30 1976, without regard to the Veteran’s MOS or where on base they were located;
  • Laos from December 1, 1965 to September 30, 1969;
  • Cambodia, specifically at Mimot or Krek, Kampong Cham Province from April 16, 1969 to April 30, 1969;
  • Guam or American Samoa or in the territorial waters thereof from January 9, 1962 to July 30, 1980;
  • Johnson Atoll or a ship that called at Johnston Atoll from January 1, 1972 to September 30, 1977.

In addition, the PACT Act added the following conditions:

  • Monoclonal gammopathy of undetermined significance (i.e., abnormal protein in the blood)
  • Hypertension (i.e., high blood pressure)

The PACT Act also created a framework for the establishment of future presumptions of service connection related to toxic exposure.

Agent Orange Presumption Should Be Applied to Burn Pit Exposure

Studies have revealed that TCDD, a dioxin and byproduct of Agent Orange, has been found in air samples from emissions of military burn pits in Iraq and Afghanistan.  In its regulation, VA includes TCDD as one of the herbicide agents that is related to developing certain harmful conditions and diseases.

In an article written for GPSOLO magazine, CCK Founding Partner Robert Chisholm argues that veterans and advocates should apply the Vietnam-era presumptions regarding herbicide exposure to Iraq and Afghanistan environmental exposures.

Recently, the 2022 PACT Act finally established presumptions for burn pit and toxic exposure in Iraq, Afghanistan, and several other nearby countries.  To learn more about these presumptions, visit CCK’s blog detailing the PACT Act exposure.



About the Author

Bio photo of Kaitlyn Degnan

Kaitlyn joined CCK in September of 2017 as an Associate Attorney. Her practice focuses on representing disabled veterans before the United States Court of Appeals for Veterans Claims.

See more about Kaitlyn