This map is a representation of herbicide spray missions in Vietnam.  The Orange areas represent concentrated spraying areas.  This map only represents fixed-wing aircraft spraying, and does not
include helicopter spraying of perimeters, or other spray methods.

The III Corps area received the heaviest concentrations of spraying,
followed by I Corps, II Corps and IV Corps.  Agent Orange was the
code name for a herbicide developed for the military, primarily for
use in tropical climates.  Although the genesis of the product goes
back to the 1940's, serious testing for military applications did not
begin until the early 1960's.  The purpose of the product was to deny
an enemy cover and concealment in dense terrain by defoliating trees
and shrubbery where the enemy could hide.
The product "Agent Orange" (a code name for the orange band that
was used to mark the drums it was stored in, was principally effective
against broad-leaf foliage, such as the dense jungle-like terrain found in
Southeast Asia.  The product was tested in Vietnam in the early 1960's,
and brought into ever widening use during the height of the war
(1967-68), though it's use was diminished and eventually discontinued
in 1971.  Agent Orange was a 50-50 mix of two chemicals, known
conventionally as 2,4,D and 2,4,5,T. The combined product was
mixed with kerosene or diesel fuel and dispersed by aircraft, vehicle,
and hand spraying.  An estimated 19 million gallons of Agent Orange
were used in South Vietnam during the war.
The earliest health concerns about Agent Orange were about the product's contamination with TCDD, or dioxin. TCDD is one of a family
of dioxins, some found in nature, and are cousins of the dibenzofurans and pcb's. The TCDD found in Agent Orange is harmful to man.  In laboratory tests on animals, TCDD has caused a wide variety of diseases, many of them fatal. TCDD is not found in nature, but rather is a man-made and always unwanted byproduct of the chemical manufacturing process.  The Agent Orange used in Vietnam was later found to be extremely contaminated with TCDD.

Since 1994, Hatfield Consultants Ltd. has been investigating the impacts of Agent Orange on the environment of Viet Nam. Agent Orange was one of many herbicides sprayed over Viet Nam by US military forces between 1962 and 1971. In total, over 10% of the area of South Viet Nam was sprayed with herbicides during the War.  Agent Orange was subsequently found to be contaminated with a highly toxic and environmentally persistent compound, dioxin. With a half-life in the environment measured in decades, dioxin has since been linked to serious medical conditions in humans.

Diseases Associated With Exposure to Agent Orange
These are the diseases which VA currently presumes resulted from exposure to herbicides like Agent Orange. The law requires that some of these diseases be at least 10% disabling under VA’s rating regulations within a deadline that began to run the day you left Vietnam. If there is a deadline, it is listed in parentheses after the name of the disease.
·Chloracne or other acneform disease consistent with chloracne.
             (Must occur within one year of exposure to Agent Orange). 
·Diabetes Mellitus, Type II
·Hodgkin’s disease
·Multiple myeloma.
·Non-Hodgkin’s lymphoma. 
·Acute and subacute peripheral neuropathy.
             (For purposes of this section, the term acute and subacute peripheral neuropathy means        temporary peripheral neuropathy that appears within weeks or months of exposure to an herbicide agent and resolves within two years of the date of onset.)
·Porphyria cutanea tarda.
             (Must occur within one year of exposure to Agent Orange). 
·Prostate cancer.
·Respiratory cancers (cancer of the lung, bronchus, larynx, or trachea). 
·Soft-tissue sarcoma (other than osteosarcoma, chondrosarcoma, Kaposi’s sarcoma, or mesothelioma).
·Chonic Lymphocytic Leukemia

What if I served in Vietnam and Have a Disease Not on VA'S List?
If you served in Vietnam and believe that you have a disease caused by herbicide exposure, but that disease is not on VA'S list of diseases associated with herbicides like Agent Orange, you may still apply for service-connection. Such a veteran needs to establish entitlement to service connection on a "direct" (rather than "presumptive") basis. In these cases, VA requires:
1)   competent medical evidence of a current disability;
2)   competent evidence of exposure to a herbicide in Vietnam; and
3)   competent medical evidence of a nexus (casual relationship) between the herbicide exposure and the current disability.
For more Q/A about Agent Orange access: