Rainbow Herbicides

Four USAF C-123s spraying Rainbow Herbicide over South Vietnam as part of Operation Ranch Hand

Agent Orange stored at Johnston Atoll in 1976, following the end of US involvement in Vietnam

The Rainbow Herbicides are a group of tactical-use chemicals used by the United States military in Southeast Asia during the Vietnam War. Success with Project AGILE field tests in 1961 with herbicides in South Vietnam was inspired by the British use of herbicides and defoliants during the Malayan Emergency in the 1950s, which led to the formal herbicidal program Trail Dust (see Operation Ranch Hand). Herbicidal warfare is the use of substances primarily designed to destroy the plant-based ecosystem of an agricultural food production area and/or to destroy dense foliage which provides the enemy with natural tactical cover.