Operation Ranch Hand was a U.S. military operation 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 ...

, lasting from 1962 until 1971. Largely inspired by the British use of chemicals 2,4,5-T and

2,4-D 2,4-Dichlorophenoxyacetic acid is an organic compound with the chemical formula . It is usually referred to by its ISO common name 2,4-D. It is a systemic herbicide that kills most broadleaf weeds by causing uncontrolled growth, but most gra ...

(

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 ...

) 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 ...

in the 1950s, it was part of the overall

herbicidal warfare Herbicidal warfare is the use of substances primarily designed to destroy the plant-based ecosystem of an area. Although herbicidal warfare use chemical substances, its main purpose is to disrupt agricultural food production and/or to destroy p ...

program during the war called "Operation Trail Dust". ''Ranch Hand'' involved spraying an estimated of defoliants and herbicides over rural areas of

South Vietnam South Vietnam, officially the Republic of Vietnam (RVN; , VNCH), was a country in Southeast Asia that existed from 1955 to 1975. It first garnered Diplomatic recognition, international recognition in 1949 as the State of Vietnam within the ...

in an attempt to deprive the

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 ...

of food and vegetation cover. Areas of Laos and Cambodia were also sprayed to a lesser extent. According to the Vietnamese government, the chemicals caused 400,000 deaths. The United States government has described these figures as "unreliable". Nearly 20,000 sorties were flown between 1961 and 1971. The "Ranch Handers" motto was "Only you can prevent a forest" – a take on the popular U.S. Forest Service poster slogan of

Smokey Bear Smokey Bear is an American campaign and advertising icon of the United States Forest Service, U.S. Forest Service in the Wildfire Prevention Campaign, which is the longest-running public service announcement campaign in United States history to ...

. During the ten years of spraying, over of forest and of crops were heavily damaged or destroyed. Around 20% of the forests of South Vietnam were sprayed at least once. The herbicides were sprayed by the U.S. Air Force flying

C-123 The Fairchild C-123 Provider is an American military transport aircraft designed by Chase Aircraft and built by Fairchild Aircraft for the U.S. Air Force. In addition to its USAF service, which included later service with the Air Force Reserve an ...

s using the call sign "Hades". The planes were fitted with specially developed spray tanks with a capacity of of herbicides. A plane sprayed a swath of land that was wide and long in about 4½ minutes, at a rate of about . Sorties usually consisted of three to five aircraft flying side by side. 95% of the herbicides and defoliants used in the war were sprayed by the U.S. Air Force as part of Operation Ranch Hand. The remaining 5% were sprayed by the U.S. Chemical Corps, other military branches, and the Republic of Vietnam using hand sprayers, spray trucks, helicopters and boats, primarily around U.S. military installations.Stellman, Jeanne et al.
The extent and patterns of usage of Agent Orange and other herbicides in Vietnam.
''Nature''. Vol 422. p. 681

Defoliants

The herbicides used were sprayed at up to 50 times the concentration than for normal agricultural use. The most common herbicide used was Herbicide Orange, more commonly referred to as

: a fifty-fifty mixture of two herbicides

(2,4-dichlorophenoxyacetic acid) and 2,4,5-T (2,4,5-trichlorophenoxyacetic acid) manufactured for the U.S. Department of Defense primarily by Monsanto Corporation and

Dow Chemical The Dow Chemical Company is an American multinational corporation headquartered in Midland, Michigan, United States. The company was among the three largest chemical producers in the world in 2021. It is the operating subsidiary of Dow Inc., ...

. The other most common color-coded ''Ranch Hand'' herbicides were Agent Blue (

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 ...

) that was primarily used against food crops, and Agent White which was often used when Agent Orange was not available. The Agents used are known as the

Rainbow Herbicides The Rainbow Herbicides are a group of tactical-use chemical weapons 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 ...

with their active ingredients, and years used were as follows: * Agent Green: 100% ''n''-butyl ester 2,4,5-T, used prior to 1966 * Agent Pink: 100% 2,4,5-T (60% ''n''-butyl ester 2,4,5-T, and 40% iso-butyl ester of 2,4,5-T) used prior to 1966 * Agent Purple: 50% 2,4,5-T (30% ''n''-butyl ester of 2,4,5-T, and 20% iso-butyl ester of 2,4,5-T) and 50% ''n''-butyl ester of

used 1961–1965 * Agent Blue (Phytar 560G): 65.6% organic

Arsenic Arsenic is a chemical element; it has Symbol (chemistry), symbol As and atomic number 33. It is a metalloid and one of the pnictogens, and therefore shares many properties with its group 15 neighbors phosphorus and antimony. Arsenic is not ...

ical (

(Ansar 138) and its sodium salt sodium cacodylate) used from 1962–1971 in powder and water solution * Agent White (Tordon 101): 21.2% (acid weight basis) triisopropanolamine

salts In chemistry, a salt or ionic compound is a chemical compound consisting of an assembly of positively charged ions ( cations) and negatively charged ions (anions), which results in a compound with no net electric charge (electrically neutral). ...

of 2,4-D and 5.7%

picloram Picloram is a systemic herbicide used for general woody plant control. It also controls a wide range of broad-leaved weeds, but most grasses are resistant.

used 1966–1971 *

or Herbicide Orange, (HO): 50% ''n''-butyl ester 2,4-D and 50% ''n''-butyl ester 2,4,5-T used 1965–1970 *Agent Orange II:50% n-butyl ester 2,4-D and 50% isooctyl ester 2,4,5-T used after 1968. *Agent Orange III: 66.6% n-butyl 2,4-D and 33.3% n-butyl ester 2,4,5-T. *Enhanced Agent Orange, Orange Plus, Super Orange (SO), or DOW Herbicide M-3393: standardized Agent Orange mixture of 2,4-D and 2,4,5-T combined with an oil-based mixture of

picloram Picloram is a systemic herbicide used for general woody plant control. It also controls a wide range of broad-leaved weeds, but most grasses are resistant.

, a proprietary Dow Chemical product called Tordon 101, an ingredient of Agent White. The herbicides were procured by the U.S. military from

Dow Chemical Company The Dow Chemical Company is an American multinational corporation headquartered in Midland, Michigan, United States. The company was among the three largest chemical producers in the world in 2021. It is the operating subsidiary of Dow Inc., ...

(all but Agent Blue),

Monsanto The Monsanto Company () was an American agrochemical and agricultural biotechnology corporation founded in 1901 and headquartered in Creve Coeur, Missouri. Monsanto's best-known product is Roundup, a glyphosate-based herbicide, developed ...

(Agent Orange, Agent Purple, and Agent Pink), Hercules Inc. (Agent Orange and Agent Purple), Thompson-Hayward Chemical Company (Agent Orange and Agent Pink), Diamond Alkali/Shamrock Company (Agent Orange, Agent Blue, Agent Purple, and Agent Pink),

United States Rubber Company Uniroyal, formerly known as the United States Rubber Company, is an American manufacturer of tires and other synthetic rubber-related products, as well as variety of items for military use, such as ammunition, explosives, chemical weapons and op ...

(Agent Orange), Thompson Chemicals Corporation (Agent Orange and Agent Pink), Agrisect Company (Agent Orange and Agent Purple), Hoffman-Taff Inc. (Agent Orange), and the Ansul Chemical Company (Agent Blue).Young, Alvin L. ''The History, Use, Disposition and Environmental Fate of Agent Orange''. Springer, 2009. p. 44. In April 1967, the entire American domestic production of 2,4,5-T was confiscated by the military; foreign sources were also tapped into, including the

Imperial Chemical Industries Imperial Chemical Industries (ICI) was a British Chemical industry, chemical company. It was, for much of its history, the largest manufacturer in Britain. Its headquarters were at Millbank in London. ICI was listed on the London Stock Exchange ...

(ICI).Der Spiegel, 32/1991
Der Tod aus Ingelheim
by Cordt Schnibben (accessed 2013-07-30) 65% of the herbicides used contained

2,4,5-trichlorophenoxyacetic acid 2,4,5-Trichlorophenoxyacetic acid (also known as 2,4,5-T), a synthetic auxin, is a chlorophenoxy acetic acid herbicide used to defoliate broad-leafed plants. It was developed in the late 1940s, synthesized by reaction of 2,4,5-trichlorophenol ...

that was contaminated with

2,3,7,8-tetrachlorodibenzodioxin 2,3,7,8-Tetrachlorodibenzo-''p-''dioxin (TCDD) is a polychlorinated dibenzo''-p-''dioxin (sometimes shortened, though inaccurately, to simply ''dioxin'') with the chemical formula CHClO. Pure TCDD is a colorless solid with no distinguishable ...

, a "''known human carcinogen''... by several different routes of exposure, including oral, dermal, and

intraperitoneal The peritoneum is the serous membrane forming the lining of the abdominal cavity or coelom in amniotes and some invertebrates, such as annelids. It covers most of the intra-abdominal (or coelomic) organs, and is composed of a layer of mesothe ...

". About of dioxin-contaminated herbicides were sprayed over

Southeast Asia Southeast Asia is the geographical United Nations geoscheme for Asia#South-eastern Asia, southeastern region of Asia, consisting of the regions that are situated south of China, east of the Indian subcontinent, and northwest of the Mainland Au ...

(mainly in Vietnam, Cambodia, and Laos) during American combat operations in the Vietnam War.Pellow, David N. ''Resisting Global Toxics: Transnational Movements for Environmental Justice'',
Google Books
, MIT Press, 2007, p. 159, (). In 2005, a New Zealand government minister was quoted and widely reported as saying that Agent Orange chemicals had been supplied from New Zealand to the United States military during the conflict. Shortly after, the same minister claimed to have been mis-quoted, although this point was less widely reported. From 1962 to 1987, ''2,4,5-T'' herbicide had been manufactured at an Ivon Watkins-Dow plant in

New Plymouth New Plymouth () is the major city of the Taranaki region on the west coast of the North Island of New Zealand. It is named after the English city of Plymouth, in Devon, from where the first English settlers to New Plymouth migrated. The New Pl ...

for domestic use, however it has not been proven that the herbicide had been exported for use by the U.S military in Vietnam.

Operations

For most of the war, Operation Ranch Hand was based at

Bien Hoa Air Base Bien Hoa Air Base (Vietnamese language, Vietnamese: ''Sân bay Biên Hòa'') is a Vietnam People's Air Force (VPAF) military airfield located in South-Central southern Vietnam about from Ho Chi Minh City, across the Dong Nai river in the norther ...

(1966–1970), for operations in the

Mekong Delta The Mekong Delta ( or simply ), also known as the Western Region () or South-western region (), is the list of regions of Vietnam, region in southwestern Vietnam where the Mekong, Mekong River River delta, approaches and empties into the sea th ...

region where U.S. Navy patrol boats were vulnerable to attack from areas of undergrowth along the water's edge. Storage, mixing, loading, and washing areas and a parking ramp were located just off the base's inside taxiway between the Hot Cargo Ramp and the control tower. For operations along the central coast and the

Ho Chi Minh trail The Ho Chi Minh Trail (), also called Annamite Range Trail () was a Military logistics, logistical network of roads and trails that ran from North Vietnam to South Vietnam through the kingdoms of Kingdom of Laos, Laos and Cambodia (1953–1970), ...

regions, ''Ranch Hand'' operated out of

Da Nang Air Base Da Nang Air Base () (1930s–1975) (also known as Da Nang Airfield, Tourane Airfield or Tourane Air Base) was a French Air Force and later Republic of Vietnam Air Force (RVNAF) facility located in the city of Da Nang, Vietnam. During the Vietnam ...

(1964–1971). Other bases of operation included

Phù Cát Air Base Phù Cát Air Base () (1966–1975) was a United States Air Force (USAF) and Republic of Vietnam Air Force (RVNAF) facility used during the Vietnam War (1959–1975). It is located north of the city of Qui Nhơn in southern Vietnam. USAF use In ...

(1968–1970), Tan Son Nhut Air Base (1962–1966), Nha Trang Air Base (1968–69), Phan Rang Air Base (1970–1972), and

Tuy Hoa Air Base Tuy Hoa Air Base was an air force base in Vietnam, being closed in 1970. It was built by the United States in 1966 and was used by the United States Air Force (USAF) during the Vietnam War in the II Corps (South Vietnam), II Corps Tactical ...

(1971–1972). Other bases were also used as temporary staging areas for ''Ranch Hand''. The Da Nang, Bien Hoa and Phu Cat Air bases are still heavily contaminated with dioxin from the herbicides, and have been placed on a priority list for containment and clean-up by the Vietnamese government. The first aerial spraying of herbicides was a test run conducted on 10 August 1961 in a village north of Đắk Tô against foliage. Testing continued into the next year and even though there was doubt in the

State Department The United States Department of State (DOS), or simply the State Department, is an executive department of the U.S. federal government responsible for the country's foreign policy and relations. Equivalent to the ministry of foreign affairs o ...

the Pentagon The Pentagon is the headquarters building of the United States Department of Defense, in Arlington County, Virginia, across the Potomac River from Washington, D.C. The building was constructed on an accelerated schedule during World War II. As ...

and the White House as to the efficacy of the herbicides, Operation Ranch Hand began in early 1962. Individual spray runs had to be approved by President John F. Kennedy until November 1962, when Kennedy gave the authority to approve most spray runs to the Military Assistance Command, Vietnam and the U.S. Ambassador to South Vietnam. ''Ranch Hand'' was given final approval to spray targets in eastern Laos in December 1965. The issue of whether or not to allow crop destruction was under great debate due to its potential of violating the

Geneva Protocol The Protocol for the Prohibition of the Use in War of Asphyxiating, Poisonous or other Gases, and of Bacteriological Methods of Warfare, usually called the Geneva Protocol, is a treaty prohibiting the use of chemical and biological weapons in ...

. However, American officials pointed out that the British had previously used 2,4,5-T and 2,4-D (virtually identical to America's use in Vietnam) on a large scale throughout the

in the 1950s in order to destroy bushes, crops, and trees in effort to deny communist insurgents the cover they needed to ambush passing convoys. Indeed, Secretary of State

Dean Rusk David Dean Rusk (February 9, 1909December 20, 1994) was the United States secretary of state from 1961 to 1969 under presidents John F. Kennedy and Lyndon B. Johnson, the second-longest serving secretary of state after Cordell Hull from the ...

told President Kennedy on 24 November 1961, that " e use of defoliant does not violate any rule of international law concerning the conduct of chemical warfare and is an accepted tactic of war. Precedent has been established by the British during the emergency in Malaya in their use of aircraft for destroying crops by chemical spraying." The president of South Vietnam,

Ngo Dinh Diem Ngô Đình Diệm ( , or ; ; 3 January 1901 – 2 November 1963) was a South Vietnamese politician who was the final prime minister of the State of Vietnam (1954–1955) and later the first president of South Vietnam (Republic of V ...

began to push the U.S. Military Advisory Group in Vietnam and the

White House The White House is the official residence and workplace of the president of the United States. Located at 1600 Pennsylvania Avenue Northwest (Washington, D.C.), NW in Washington, D.C., it has served as the residence of every U.S. president ...

to begin crop destruction in September 1961, but it was not until October 1962 when the White House gave approval for limited testing of Agent Blue against crops in an area believed to be controlled by the Viet Cong. Soon after, crop destruction became an integral part of the ''Ranch Hand'' program. Targets for the spray runs were carefully selected to satisfy the strategic and psychological operations goals of the U.S. and South Vietnamese military. Spray runs were surveyed to pinpoint the target area and then placed on a priority list. Due to the low altitude (ideally required for spraying, the C-123s were escorted by fighter aircraft or helicopter gunship that would strafe or bomb the target area in order to draw out any ground fire if the area was believed to be 'hot'. Spray runs were planned to enable as straight a run as possible to limit the amount of time the planes flew at low altitude. Data on the spray runs, their targets, the herbicide used and amount used, weather conditions and other details were recorded and later put into a database called the Herbicide Reporting System (HERBS) tapes. The effectiveness of the spraying was influenced by many factors including weather and terrain. Spray runs occurred during the early morning hours before temperatures rose above and the winds picked up. Mangroves in the Delta region required only one spraying and did not survive once defoliated, whereas dense forests in the uplands required two or more spray runs. Within two to three weeks of spraying, the leaves would drop from the trees, which would remain bare until the next rainy season. In order to defoliate the lower stories of forest cover, one or more follow-up spray runs were needed. About 10 percent of the trees sprayed died from a single spray run. Multiple spraying resulted in increased mortality for the trees, as did following up the herbicide missions with napalm or bombing strikes.

Scientific community reaction

The use of herbicides in the Vietnam War was controversial from the beginning, particularly for crop destruction. The scientific community began to protest the use of herbicides in Vietnam as early as 1964, when the

Federation of American Scientists The Federation of American Scientists (FAS) is an American nonprofit global policy think tank with the stated intent of using science and scientific analysis to attempt to make the world more secure. FAS was founded in 1945 by a group of scient ...

objected to the use of defoliants. The

American Association for the Advancement of Science The American Association for the Advancement of Science (AAAS) is a United States–based international nonprofit with the stated mission of promoting cooperation among scientists, defending scientific freedom, encouraging scientific responsib ...

(AAAS) issued a resolution in 1966 calling for a field investigation of the herbicide program in Vietnam. In 1967, seventeen

Nobel laureate The Nobel Prizes (, ) are awarded annually by the Royal Swedish Academy of Sciences, the Swedish Academy, the Karolinska Institutet, and the Norwegian Nobel Committee to individuals and organizations who make outstanding contributions in th ...

s and 5,000 other scientists signed a petition asking for the immediate end to the use of herbicides in Vietnam. In 1970, AAAS sent a team of scientists—the Herbicide Assessment Commission (HAC), consisting of Matthew Meselson, Arthur Westing, John Constable, and Robert Cook—to conduct field tests of the ecological impacts of the herbicide program in Vietnam. A 1969 study by the Bionetics Research Laboratory found that 2,4,5-T could cause birth defects and stillbirths in mice. The U.S. government suspended the military use of 2,4,5-T in the U.S. in April 1970. Sporadic crop destruction sorties using Agent Blue and Agent White continued throughout 1970 until the final ''Ranch Hand'' run was flown on 7 January 1971.

Human impact

The use of herbicides as a defoliant had long-term destructive effects on the people of Vietnam and their land and ecology, as well as on those who fled in the mass exodus from 1978 to the early 1990s. According to the Vietnamese government, the US program exposed approximately 4.8 million Vietnamese people to Agent Orange, resulting in 400,000 deaths due to a range of cancers and other ailments.Reuters, 10 Aug. 200
"Vietnam Seeks Funds for Agent Orange Victims"
/ref> Hindsight corrective studies indicate that previous estimates of Agent Orange exposure were biased by government intervention and under-guessing, such that current estimates for dioxin release are almost double those previously predicted. According to the Vietnamese Government, census data indicates that the United States military directly sprayed upon millions of Vietnamese during strategic Agent Orange use. According to the Vietnamese government, the program caused three million Vietnamese health problems, with 150,000 children born with severe birth defects, and 24% of the area of Vietnam being defoliated. The Red Cross of Vietnam estimates that up to one million people were disabled or have health problems as a result of exposure to Agent Orange. The United States government has described these figures as "unreliable". According to the Department of Veteran Affairs, 2.6 million U.S. military personnel were exposed and hundreds of thousands of veterans are eligible for treatment for Agent Orange-related illnesses.News Australia. 25 May 2015
"Vietnam's Horrific Legacy: The Children of Agent Orange"
/ref>

References

External links