Use during the war
Agent Orange was the most widely used defoliant during the Vietnam War. The chemical defoliants were used to clear forests to prevent enemy troops from hiding and to make bombing targets more visible. Agent Orange is one of the Rainbow Herbicides, a group of herbicides named after the coloured stripes painted on the barrels they were stored into.
The Rainbow Herbicides had a tactical use in the attrition strategy the United States employed against North Vietnam and the Viet Cong. They were mainly used in Operation Ranch Hand, a massive chemical warfare campaign that went on from 1962 until 1971 and was meant to take away the enemy's advantage in the terrain and to deprive them of food resources. Aircrafts, helicopters, trucks, boats, and hand sprayers were used to spread the chemicals. It is estimated that during this operation, US and South Vietnamese forces sprayed more than 20.2 million gallons of herbicides over Vietnam, out of which 13 million gallons were of Agent Orange. Consequently, between 2 to 4 million people were exposed to these substances during the war.
Harmful effects and protests
The herbicides were contaminated with dioxin, a persistent toxic chemical. This chemical lingers in the water and in the local animals and plants that gets exposed to it. However, at the time, the extent of the toxicity of dioxin was not widely known.