"And what's this rash that comes and goes, can you tell me what it means? God help me, I was only nineteen."

Agent Orange was the code name for a one of the "rainbow herbicides" 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 its 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 45 million litres of Agent Orange were usedby the U.S military in South Vietnam, Laos and Cambodia during the war to defoliate rural/forested land - depriving guerrillas of food and cover - and as part of a general policy of forced draft urbanisation by destroying the ability of peasants to support themselves in the countryside.
According to Vietnam Red Cross as many as 3 million Vietnamese people have been affected by Agent Orange including at least 150,000 children born with birth defects. Studies of veterans who served in the south during the war compared to those who did not have found that those who went south have increased rates of cancer, nerve, digestive, skin and respiratory disorders. Among the cancers veterans from the south had higher rates of throat cancer, acute/chronic leukemia, Hodgkin’s lymphoma and non-Hodgkin’s lymphoma, prostate cancer, lung cancer, soft tissue sarcoma and liver cancer.
Relevance to Apocalypse Now
Although it would be tempting to attribute Coppola's orange filmscape in Apocalypse Now to a reference to Agent Orange, the fact is that, even though links were made between the chemical and birth defects in the late 1960's (leading to discontinuation of usage in 1971), the after effects of Agent Orange and it's implementation in the Vietnam conflict was not particularly evident in the public consciousness until well after the film had been made. This effect is more likely to be due to the filmstock used by Coppola than any form of symbolism. Agent Orange does, however, have some relevance to Heart of Darkness. Think of the futility of clearing millions of acres of jungle only to have it grow back within a very short space of time. Then think about trying to build a road through the Congo, for example."Once a white man in an unbuttoned uniform, camping on the path with an armed escort of lank Zanzibaris, very hospitable and festive - not to say drunk. Was looking after ther upkeep of the road, he declared. Can't say I saw any road or upkeep..." Bibliography:
The Agent Orange Website:
Wikipedia - Agent Orange: