Agent Orange is the code name for a powerful herbicide and defoliant used widely by the U.S. military during the Vietnam War. Agent Orange was used from 1961 to 1971 and has disputedly caused serious harm to the health of exposed Vietnamese, Canadians and Americans, their children and grandchildren.

Agent Orange is a roughly 1:1 mixture of the herbicides 2,4-D (2,4-dichlorophenoxyacetic acid) and 2,4,5-T (2,4,5-trichlorophenoxyacetic acid). These herbicides were developed during the 1940s for use in controlling broad-leaf plants. First introduced in 1947, both of these herbicides had widespread use in agriculture by the middle of the 1950s.

During the Vietnam War, Agent Orange's official military purpose was to remove the leaves of trees to prevent guerrilla fighters of the National Liberation Front from hiding. Agent Orange is a colorless liquid: its name was from the color of the stripes on the barrels used to transport it.

Agent Orange as a military defoliant was discontinued in 1971, after over 6,000 spraying missions in Vietnam and Cambodia; 2,4-D continues to be widely used as an herbicide. The use of 2,4,5-T has been banned in the U.S. and many other countries.

Agent Blue is a herbicide, similar to Agent Orange, used by the United States during the Vietnam War. It was sprayed on rice paddies and other crops, in an attempt to starve the Vietnamese of valuable crops.

As rice is incredibly durable, and difficult to destroy with conventional explosives, and does not burn, the weapon of choice was herbicides.

Agent Blue affects plants by causing them to dry out. As rice is highly dependant on water to live, using Agent Blue on these paddies can destroy an entire field and leave it unsuitable for further planting.

Agent Blue is a 2:1 mixture by weight of Na-Dimethyl Arsenate (Na Cacodylate) and Dimethyl Arsenic (Cacodylic acid).

Today, large quantities of the chemical named Agent Blue are still used on lawns and crops throughout the country.

Taken from ZNet Ecology:
"Arsenical herbicides containing cacodylic acid as an active ingredient are still used today as weed-killers. In the US they are used extensively, from golf courses to backyards. They are also sprayed on cotton fields, drying out the plants before harvesting. So common -- and so profitable -- is the original commercial form of Agent Blue that it was among 10 toxic insecticides, fungicides and herbicides partially deregulated by the US Environmental Protection Agency (EPA) in February 2004. Specific limits on toxic residues in meat, milk, poultry, and eggs were removed."

Agent Purple is a cousin of the Agent Orange and Agent Pink herbicides. It contained three times the cancer-causing dioxin levels found in Agent Orange.

4:1 mixture of 2,4-Dichlorophenoxyacetic acid and Picloram