Agent Orange is the code name for a powerful herbicide and defoliant used by the U.S. military in its Herbicidal Warfare program during the Vietnam War. During the Vietnam War, an estimated 80 000 m³ of Agent Orange were deployed in South Vietnam.
Agent Orange's usage from 1961 to 1971 was by far the most used of the so-called "Rainbow Herbicides" used during the program. Degradation of Agent Orange (as well as Agents Purple, Pink, and Green) released dioxins, which have caused health problems for those exposed during the Vietnam War. Agents Blue and White were part of the same program but did not contain dioxins.
Agent orange, given its name from the colour of the 55 U.S. gallon (210 litre) orange-striped barrels it was shipped in. It is a roughly 1:1 mixture of two phenoxyl herbicides in ester form, 2,4-dichlorophenoxyacetic acid (2,4-D) and 2,4,5-trichlorophenoxyacetic acid (2,4,5-T). Internal memos from the companies that manufactured it reveal that at the time Agent Orange was sold to the U.S. government for use in Vietnam it was known that it contained dioxin, 2,3,7,8-tetrachlorodibenzodioxin (TCDD), a by-product of the manufacture of 2,4-D and 2,4,5-T. The National Toxicology Program has classified TCDD to be a human carcinogen, frequently associated with soft-tissue sarcoma, Non-Hodgkin's lymphoma, Hodgkin's disease and chronic lymphocytic leukemia (CLL). In a study by the Institute of Medicine, a link has been found between dioxin exposure and diabetes. Porphyria cutanea tarda (a type of skin disease), acute and subacute transient peripheral neuropathy, spina bifida, Type 2 diabetes, and acute myelogenous leukemia found only in the second or third generation.
The herbicide 2,4-D, one of the most-used herbicides in the world today, may also contain dioxin.
The LD50, according to US EPA 2,4-D Reregistration Eligibility Decision, 2006,is 639 mg/kg. Single oral doses of 5 and 30 mg/kg body weight did not cause any acute toxic effects in human volunteers.
During the Vietnam war, between 1962 and 1971, the United States military sprayed 77 million litres of chemical defoliants in South Vietnam as part of a defoliant program to deny cover for their Vietnamese opponents.
According to Vietnamese Ministry of Foreign Affairs, 4.8 million Vietnamese people were exposed to agent orange, resulting in 400,000 deaths and disabilities, and 500,000 children born with birth defects. The most affected zones are the mountainous area along Truong Son (Long Mountains) and the border between Vietnam and Cambodia. The affected residents are living in sub-standard conditions with many genetic diseases.
The U.S. military, with the permission of the Canadian government, secretly tested many unregistered U.S. military herbicides, including Agent Orange, in the forests near the Canadian Forces Base Gagetown in New Brunswick in 1966 and 1967. On September 12, 2007, Greg Thompson, Minister of Veterans Affairs, announced that the government of Canada is offering a one-time ex gratia payment of $20,000 as the compensation package for Agent Orange exposure at CFB Gagetown.
On August 8, 2007, the United States Environmental Protection Agency issued a ruling which stated existing data do not support a conclusion that links human cancer to 2,4-D exposure.
The amine salt formulations can cause irreversible eye damage; ester formulations are considered non-irritating to the eyes.
Much of the information on the effects of Agent Orange in Vietnam until the 21st century, were compiled by Vietnamese scientists in Vietnamese and largely unavailable to the worldwide English reader. However, general public perception in Vietnam is that the effects are severe and clearly visible in children of veterans and people in affected areas.
