Agent Blue is one of the " rainbow herbicides" that is known for use by the

United States The United States of America (USA), also known as the United States (U.S.) or America, is a country primarily located in North America. It is a federal republic of 50 U.S. state, states and a federal capital district, Washington, D.C. The 48 ...

during the

Vietnam War The Vietnam War (1 November 1955 – 30 April 1975) was an armed conflict in Vietnam, Laos, and Cambodia fought between North Vietnam (Democratic Republic of Vietnam) and South Vietnam (Republic of Vietnam) and their allies. North Vietnam w ...

. It contained a mixture of dimethylarsinic acid (also known as

cacodylic acid Cacodylic acid is an organoarsenic compound with the formula (CH3)2 AsO2H. With the formula R2As(O)OH, it is the simplest of the arsinic acids. It is a colorless solid that is soluble in water. Neutralization of cacodylic acid with base gives ca ...

) and its related salt, sodium cacodylate, and water.

History

Largely inspired by the British use of

herbicides Herbicides (, ), also commonly known as weed killers, are substances used to control undesired plants, also known as weeds.EPA. February 201Pesticides Industry. Sales and Usage 2006 and 2007: Market Estimates. Summary in press releasMain page f ...

and defoliants during the

Malayan Emergency The Malayan Emergency, also known as the Anti–British National Liberation War, was a guerrilla warfare, guerrilla war fought in Federation of Malaya, Malaya between communist pro-independence fighters of the Malayan National Liberation Arm ...

, killing

rice Rice is a cereal grain and in its Domestication, domesticated form is the staple food of over half of the world's population, particularly in Asia and Africa. Rice is the seed of the grass species ''Oryza sativa'' (Asian rice)—or, much l ...

was a military strategy from the very start of U.S. military involvement in

Vietnam Vietnam, officially the Socialist Republic of Vietnam (SRV), is a country at the eastern edge of mainland Southeast Asia, with an area of about and a population of over 100 million, making it the world's List of countries and depende ...

. At first, U.S. soldiers attempted to blow up rice paddies and rice stocks, using

mortars Mortar may refer to: * Mortar (weapon), an indirect-fire infantry weapon * Mortar (masonry), a material used to fill the gaps between blocks and bind them together * Mortar and pestle, a tool pair used to crush or grind * Mortar, Bihar, a village i ...

and

hand grenade A grenade is a small explosive weapon typically thrown by hand (also called hand grenade), but can also refer to a Shell (projectile), shell (explosive projectile) shot from the muzzle of a rifle (as a rifle grenade) or a grenade launcher. A mod ...

s. But grains of rice were far more durable than they understood, and were not easily destroyed. Every grain that survived was a seed to be collected and planted again. A 1967 report to the International War Crimes Tribunal stated that "The soldiers discovered that rice is one of the most maddeningly difficult substances to destroy; using

thermite Thermite () is a pyrotechnic composition of powder metallurgy, metal powder and metal oxide. When ignited by heat or chemical reaction, thermite undergoes an exothermic redox, reduction-oxidation (redox) reaction. Most varieties are not explos ...

metal grenades it is almost impossible to make it burn and, even if one succeeds in scattering the rice, this does not stop it being harvested by patient men." The purpose of Agent Blue was to kill narrow-leafed plants and trees (grass, rice, bamboo, banana, etc.) "

Operation Ranch Hand Operation Ranch Hand was a U.S. military operation during the Vietnam War, lasting from 1962 until 1971. Largely inspired by the British use of chemicals 2,4,5-T and 2,4-D (Agent Orange) during the Malayan Emergency in the 1950s, it was part of ...

" was military code for spraying of herbicides from U.S. Air Force aircraft in Southeast Asia from 1962 through 1971. Reissue: . The widespread use of herbicides in Southeast Asia during the Vietnam War was a unique military operation in that it was meant to kill the plants that provided cover. The continued use of Agent Blue and the other "Rainbow Herbicides" by the United States was primarily meant as an operation to take away the enemy's advantage on the terrain as well as deprive them of food. Between 1962 and 1971, the U.S. used an estimated of herbicides as chemical weapons for "defoliation and crop destruction" which fell mostly on the forest of South Vietnam, but was eventually used in

Laos Laos, officially the Lao People's Democratic Republic (LPDR), is the only landlocked country in Southeast Asia. It is bordered by Myanmar and China to the northwest, Vietnam to the east, Cambodia to the southeast, and Thailand to the west and ...

as well to kill crops in order to deprive the communist

Viet Cong The Viet Cong (VC) was an epithet and umbrella term to refer to the communist-driven armed movement and united front organization in South Vietnam. It was formally organized as and led by the National Liberation Front of South Vietnam, and ...

and North Vietnamese troops of food. It was sprayed on rice paddies and other crops in an attempt to deprive the Viet Cong of the valuable crops the plants provided. Agent Blue is chemically unrelated to the more infamous

Agent Orange Agent Orange is a chemical herbicide and defoliant, one of the tactical uses of Rainbow Herbicides. It was used by the U.S. military as part of its herbicidal warfare program, Operation Ranch Hand, during the Vietnam War from 1962 to 1971. T ...

and other herbicides used during the war. Agent Blue, a herbicide containing cacodylic acid and sodium cacodylate, was used by the United States military during the Vietnam War to destroy plant life, particularly in rice paddies, which was a major food source for the Viet Cong and the North Vietnamese Army. The herbicide caused plants to dry out and become unsuitable for further planting. Agent Blue was also used in areas where the foliage was a hindrance to military operations. The Viet Cong were familiar with the abundant plant life in Vietnam, giving them an advantage in fighting on the battlefield. Approximately of Agent Blue were used in Vietnam during the war, with delivery of the herbicide primarily done by the Ansul Chemical Company. The US found themselves at a disadvantage and based on the precedent set by the British in Malaya, decided that the most vicious (best) retaliation would be to take the Vietcong's advantage away from them by removing their cover. Along roads, canals, railroads, and other transportation networks, Ranch Hand cleared several hundred yards using the herbicides to make ambushes more difficult for their enemies. In Laos, the herbicide removed the jungle canopy from the roads and trails used for infiltrating men and supplies, making them more vulnerable to attack from the air. During the Vietnam War, about of Agent Blue, a herbicide containing 26.4% sodium cacodylate and 4.7% cacodylic acid in water, were used. The Ansul Chemical Company supplied the herbicide Phytar 560 with these chemical compounds from 1965 onwards. Cacodylic acid is still used on crops throughout the United States. Arsenical herbicides containing cacodylic acid as an active ingredient are still used today as weed-killers. It sprayed on

cotton Cotton (), first recorded in ancient India, is a soft, fluffy staple fiber that grows in a boll, or protective case, around the seeds of the cotton plants of the genus '' Gossypium'' in the mallow family Malvaceae. The fiber is almost pure ...

fields, drying out the cotton plants before harvesting. In 2009, the MSMA uses on athletic fields, parks, residential lawns, forestry, non-bearing fruit and nut trees, and citrus orchards were also canceled.

References

External links

Agent Blue
covered on '' The World'', May 1, 2025 {{Rainbow Herbicides Arsenical herbicides Defoliants Military equipment of the Vietnam War