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Veterans Law

Exposure and Use of Agent Orange in Thailand

July 20, 2018
Agent Orange in Thailand herbicide exposure veteran

First, What Is Agent Orange?

Agent Orange is an herbicide that was used by the United States during the Vietnam War. Agent Orange was made up of 2,4-D, 2,4,5-T and its contaminant TCDD, which is a highly toxic byproduct of producing Agent Orange. VA’s regulation 38 C.F.R. 3.307 defines an herbicide agent as 2,4-D; 2,4,5-T and its contaminant TCDD (also known as dioxin); cacodylic acid, and picloram. Agent Orange is just one of the “rainbow herbicides” that the United States used during the Vietnam War including Agent Blue and Agent White, among many others.

The Agent Orange Presumption

The Presumption of Exposure

Following the Vietnam War, many Vietnam veterans experienced rare and severe health conditions they thought to be the result of their exposure to Agent Orange during their service. VA and Congress had difficulty determining who was exposed to herbicides during their service in Vietnam, as well as where, for how long, and how much they were exposed. Since they could not determine who was exposed, Congress created a presumption of exposure to herbicide agents in the Republic of Vietnam. This presumption gave all Vietnam veterans the benefit of the doubt that they were exposed to herbicides. This is what we call the presumption of exposure.

The regulation itself states that veterans “who, during active military, naval, or air service, served in the Republic of Vietnam during the period beginning on January 9, 1962, and ending on May 7, 1975” were exposed to herbicide agents. All veterans who served in-country Vietnam (“boots-on-the-ground”) are covered under this regulation, as well as those veterans who served on ships that navigated the inland waterways of Vietnam (Brown Water). Blue Water veterans have recently been granted a similar presumption of exposure under the Blue Water Navy Vietnam Veterans Act of 2019.

The Presumption of Service Connection

The next step is what we call the presumption of service connection. VA’s regulation lists several conditions that the Institute of Medicine has determined to be associated with herbicide exposure. If VA determines that a veteran was exposed to herbicides (either through the presumption of exposure or on a facts-found basis), it will then presume that the veteran’s herbicide exposure caused them to develop one of the following conditions:

  • AL amyloidosis
  • Chronic B-cell Leukemias
  • Chloracne
  • Diabetes Mellitus Type II
  • Hodgkin’s Disease and Non-Hodgkin’s Lymphoma
  • Ischemic Heart Disease
  • Multiple Myeloma
  • Parkinson’s Disease
  • Early-onset peripheral neuropathy
  • Porphyria Cutanea Tarda
  • Prostate Cancer
  • Respiratory Cancer (e.g. bronchus cancer, larynx cancer, lung cancer, trachea cancer)
  • Soft Tissue Sarcomas

In short, if a veteran is exposed to herbicides, whether on a presumptive or facts-found basis, VA will extend them the presumption of service connection for these conditions.

Above, CCK subject-matter expert and VA appellate practitioner Kerry Baker and attorney Maura Clancy sat down to discuss Agent Orange exposure in Thailand during the Vietnam War and how VA handles claims for conditions due to exposure to the herbicide Agent Orange.

We Help Veterans Appeal Agent Orange Claims

The Use of Agent Orange in Thailand

Veterans who served in Thailand during the Vietnam War are not included in VA’s presumption of exposure. However, records show that Agent Orange and other herbicides were used on certain Royal Thai Air Force Bases in Thailand during the Vietnam War.

Where and Why Was It Used?

Agent Orange and other herbicides were used to clear the perimeter areas of a number of Royal Thai Air Force Bases in Thailand to increase visibility and prevent guerrilla attacks. Some of these bases include U-Tapao, Ubon, Udorn, and Takhli, among others.

Operation Ranch Hand and Thailand

Operation Ranch Hand was a US military operation in which modified C-123 aircraft sprayed herbicides over large areas of the jungles of Vietnam to destroy enemy cover. Planes used in Operation Ranch Hand flew into Thailand, and many planes that sprayed herbicides in Laos flew out of Air Force bases in Thailand as well. Herbicides had to be loaded on to the planes at the Air Force bases in Thailand, and there are records that show that Agent Orange was delivered to bases in Thailand.

What Does VA Say?

VA does have a policy regarding veterans who served and were exposed to Agent Orange in Thailand. This policy recognizes that herbicides were used, but it only acknowledges that Agent Orange and other herbicides were used on the perimeters of certain Royal Thai Air Force Bases, as well as some Army bases. This understanding stems from a 1973 CHECO Report that looked at perimeter security on Thailand bases during the Vietnam War. Although the Report was not about herbicide use on the bases, it discussed Thailand bases getting attacked and documented herbicide use on the perimeters of the bases to clear vegetation in the hopes of preventing attacks.

What about the Perimeter?

As mentioned, VA does recognize that herbicides were used along the perimeter of Air Force bases in Thailand. However, VA contends that only those who worked on or near the perimeter may have been exposed to herbicides. According to VA’s policy, if a veteran’s Military Occupational Specialty (MOS) was a security guard or patrol dog handler, VA will concede that you were on the perimeter of the base and exposed to herbicides. However, VA also says that it will concede exposure if they can show that they were on or near the perimeter through credible evidence. Credible evidence can take the form of official records or lay evidence (see “What Can Veterans Submit to Help Their Claim?” below).

Veterans should keep in mind that while VA requires a veteran to show that they were on or near the perimeter of the base, near is never defined. In addition to this, VA does not consistently apply this policy to veteran’s claims for disability benefits as due to exposure to Agent Orange in Thailand, often resulting in determinations being made on a case-by-case basis.

Drift Zones

“Drift zones” refer to 500-meter buffer zones around where herbicides were being sprayed, as discussed in a Department of the Army Field Manual titled “Tactical Employment of Herbicides.” Drift zones can be interpreted to fall in the category of “near the perimeter” for purposes of showing herbicide exposure on Thailand bases. VA typically denies the claims of veterans who did not have an MOS that would put them on the perimeter of the base in Thailand, but this largely discounts veterans who were in the drift zone. Credible evidence showing that a veteran was in a drift zone could count as evidence that they were “near the perimeter” of the base.

This is especially important because the distance between the base perimeter and other base activities and facilities, such as living quarters and offices, were well within 500-meters from the perimeter of these Thailand bases.

VA’s Myth of Tactical vs. Commercial Herbicides

When it comes to disability claims for conditions due to exposure to herbicides and Agent Orange in Thailand, VA often attempts to make a distinction between tactical herbicides and commercial herbicides as a basis on which to deny claims. When it comes to claims pertaining to herbicides used in Vietnam, VA will often say that the herbicides veterans were exposed to were “tactical herbicides.” However, VA will then state in claims pertaining to use of herbicides and Agent Orange in Thailand that the herbicides veterans were exposed to there were “commercial herbicides.”

First, records show that the herbicides that were sent to Vietnam were also sent to Thailand, so veterans in both Vietnam and Thailand were likely exposed to the same herbicides. Second, simply because an herbicide was used in a tactical environment does not mean that it is a “tactical herbicide.” Just because herbicides such as Agent Orange were used in different countries, does not mean that their chemical make-up changed depending on in which country it was used. While VA likes to make the distinction between commercial and tactical herbicides, the same herbicides were used in both Vietnam and Thailand.

What Can Veterans Submit to Help Their Claim?

As discussed, if VA does not concede that a veteran was on or near the perimeter based on their MOS, the veteran will have to submit credible evidence showing that they were on or near the perimeter of the base. Credible evidence can take many different forms. In general, giving VA as much detail as possible can be helpful when submitting evidence for these types of claims.

Lay Statements

Lay statements can go a long way as evidence that a veteran was stationed on or near the perimeter of a base. A comprehensive statement should lay out, in detail, what the veteran was doing that put them on or near the perimeter, at what base they were stationed, what their MOS was, and how close they were to the perimeter. If a veteran spent time on the perimeter during their leisure time, they should lay out what they did during that time and why they were near the perimeter.

Buddy statements from fellow service members can also be helpful to corroborate a veteran’s statement to VA.


If a veteran has pictures from their service in Thailand that show them on or near the perimeter, those can be submitted to VA as evidence that they spent time around the perimeter of the base. Pictures of the Thailand base can also be helpful to show VA where you were in relation to the perimeter.


CCK’s Petition for Rulemaking for Thailand Claims

As mentioned, VA does have a policy for addressing Agent Orange in Thailand claims. However, this policy is not consistently applied nor has it gone through formal rulemaking. In August 2015, CCK noticed that VA made some substantial changes to their Thailand policy in their adjudication manual, the M-21. The changes limited the number of Thailand veterans that could be eligible for benefits and the policy was implemented without notice.

We requested that VA create a regulation by filing a Petition for Rulemaking. In essence, because of all the inconsistencies in VA’s adjudication of these claims, CCK requested that VA consider making a formal rule for Thailand claims. VA granted our request two years after we filed the petition. However, it is unclear when VA will create the policy and move forward with our request.

Was your VA Disability Claim Denied?

The attorneys at Chisholm Chisholm & Kilpatrick LTD have years of experience in handling Thailand veterans’ Agent Orange exposure claims. If your VA disability claim has been denied, we may be able to help you. Contact our office today for a free case evaluation at (800) 544-9144.