Agent Purple

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Ranch Hand UC-123B spraying defoliant in 1962 UC-123B Ranch Hand spraying 1962.jpg
Ranch Hand UC-123B spraying defoliant in 1962

Agent Purple is the code name for a powerful herbicide and defoliant used by the U.S. military in their herbicidal warfare program during the Vietnam War. The name comes from the purple stripe painted on the barrels to identify the contents. Largely inspired by the British use of herbicides and defoliants during the Malayan Emergency, it was one of the so-called "Rainbow Herbicides" that included the more infamous Agent Orange. Agent Purple and Orange were also used to clear brush in Canada.

Agent Purple was chemically similar to the better-known Agent Orange, both of them were consisting of a mixture of the herbicides 2,4-D and 2,4,5-T and in both cases the 2,4-D and 2,4,5-T constituted equal shares of the Agent. [1] The difference was in the form of 2,4,5-T. While all the 2,4,5-T in Agent Orange was as the n-butyl ester, the 2,4,5-T in Agent Purple was itself mixture of n-butyl and isobutyl ester forms (60%:40% respectively). [1] The Agent Purple had then the following composition: 50% n-butyl ester 2,4-D, 30% n-butyl ester 2,4,5-T, and 20% isobutyl ester 2,4,5-T. [1]

Even prior to Operation Ranch Hand (1962-1971) it was known [2] [3] [4] [5] [6] [7] that 2,4,5-T, and thus Agent Purple, Agent Pink, Agent Green, and Agent Orange, were contaminated with tetrachlorodibenzodioxin (TCDD), an extremely toxic and persistent by-product formed during synthesis. Dioxin-levels varied considerably from batch to batch, and even within the same batch; generally, agents produced earlier, such as Agent Purple and Agent Pink suffered from higher levels of contamination. A 2003 Nature paper by Stellman et al., which re-apprised the average TCDD content of Agent Orange from the 3  ppm that USAF had reported to a level of 13 ppm, also estimated that Agent Purple may have had 32.8 ppm of TCDD on average. A sample of Agent Purple archived at Eglin Air Force Base had an even higher content of 45 ppm TCDD. [8]

Agent Purple was used only in the earliest stages of the spraying program, between 1962 and 1965 as well as in earlier tests conducted by the US military outside of Vietnam. [9] About 500,000 U.S. gal (1,900,000 L; 420,000 imp gal) were sprayed in Vietnam in total. [10] When the need to clear brush around CFB Gagetown in Canada arose, quantities of Agent Purple and Agent Orange were also sprayed there in a testing program during 1966 and 1967. [11] [12]

Related Research Articles

<span class="mw-page-title-main">Agent Orange</span> Herbicide used by the US in the Vietnam War

Agent Orange is a chemical herbicide and defoliant, one of the tactical use Rainbow Herbicides.

Polychlorinated dibenzodioxins (PCDDs), or simply dioxins, are a group of long-lived polyhalogenated organic compounds that are primarily anthropogenic, and contribute toxic, persistent organic pollution in the environment.

<span class="mw-page-title-main">Herbicide</span> Chemical used to kill unwanted plants

Herbicides, also commonly known as weed killers, are substances used to control undesired plants, also known as weeds. Selective herbicides control specific weed species while leaving the desired crop relatively unharmed, while non-selective herbicides can be used to clear waste ground, industrial and construction sites, railways and railway embankments as they kill all plant material with which they come into contact. Apart from selective/non-selective, other important distinctions include persistence, means of uptake, and mechanism of action. Historically, products such as common salt and other metal salts were used as herbicides, however, these have gradually fallen out of favor, and in some countries, a number of these are banned due to their persistence in soil, and toxicity and groundwater contamination concerns. Herbicides have also been used in warfare and conflict.

<span class="mw-page-title-main">Operation Ranch Hand</span> 1962–1971 US herbicidal warfare operation in the Vietnam War

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 2,4,5-T and 2,4-D during the Malayan Emergency in the 1950s, it was part of the overall herbicidal warfare program during the war called "Operation Trail Dust". Ranch Hand involved spraying an estimated 19 million U.S. gallons (72,000 m3) of defoliants and herbicides over rural areas of South Vietnam in an attempt to deprive the Viet Cong 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.

<span class="mw-page-title-main">Seveso disaster</span> Toxic chemical leak in Italy in 1976

The Seveso disaster was an industrial accident that occurred around 12:37 pm on 10 July 1976, in a small chemical manufacturing plant approximately 20 kilometres (12 mi) north of Milan in the Lombardy region of Italy. It resulted in the highest known exposure to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) in residential populations, which gave rise to numerous scientific studies and standardized industrial safety regulations, including the European Union's Seveso III Directive. This accident was ranked eighth in a list of the worst man-made environmental disasters by Time magazine in 2010.

<span class="mw-page-title-main">Defoliant</span> Chemical sprayed or dusted on plants to cause its leaves to fall off

A defoliant is any herbicidal chemical sprayed or dusted on plants to cause their leaves to fall off. Defoliants are widely used for the selective removal of weeds in managing croplands and lawns. Worldwide use of defoliants, along with the development of other herbicides and pesticides, allowed for the Green Revolution, an increase in agricultural production in mid-20th century. Defoliants have also been used in warfare as a means to deprive an enemy of food crops and/or hiding cover, most notably by the United Kingdom during the Malayan Emergency and the United States in the Vietnam War. Defoliants were also used by Indonesian forces in various internal security operations.

<span class="mw-page-title-main">Herbicidal warfare</span> Use of substances to destroy crops or other plants

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 plants which provide cover or concealment to the enemy, not to asphyxiate or poison humans and/or destroy human-made structures. Herbicidal warfare has been forbidden by the Environmental Modification Convention since 1978, which bans "any technique for changing the composition or structure of the Earth's biota".

<span class="mw-page-title-main">Agent White</span>

Agent White is the code name for a herbicide used by the U.S. military in its herbicidal warfare program during the Vietnam War. The name comes from the regulatory requirements of identifying each container of the various herbicides through the addition of colored stripes. The colors used were orange, purple, pink, blue, and white by the manufacturers to ensure that the contents were easily identifiable during shipment and usage, as the colors were selected by the U.S. government. Largely inspired by the British use of herbicides and defoliants during the Malayan Emergency, it was one of the so-called "rainbow herbicides".

<span class="mw-page-title-main">Agent Green</span>

Agent Green is the code name for a powerful herbicide and defoliant used by the U.S. military in its herbicidal warfare program during the Vietnam War. The name comes from the green stripe painted on the barrels to identify the contents. Largely inspired by the British use of herbicides and defoliants during the Malayan Emergency, it was one of the so-called "Rainbow Herbicides". Agent Green was only used between 1962 and 1964, during the early "testing" stages of the spraying program.

<span class="mw-page-title-main">2,4,5-Trichlorophenoxyacetic acid</span> Chemical compound

2,4,5-Trichlorophenoxyacetic acid, 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 and chloroacetic acid. It was widely used in the agricultural industry until being phased out, starting in the late 1970s due to toxicity concerns. Agent Orange, a defoliant used by the British in the Malayan Emergency and the U.S. in the Vietnam War, was equal parts 2,4,5-T and 2,4-D. 2,4,5-T itself is toxic with a NOAEL of 3 mg/kg/day and a LOAEL of 10 mg/kg/day. Agent Pink contained 100% 2,4,5-T. Additionally, the manufacturing process for 2,4,5-T contaminates this chemical with trace amounts of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). TCDD is a carcinogenic persistent organic pollutant with long-term effects on the environment. With proper temperature control during production of 2,4,5-T, TCDD levels can be held to about .005 ppm. Before the TCDD risk was well understood, early production facilities lacked proper temperature controls and individual batches tested later were found to have as much as 60 ppm of TCDD.

<span class="mw-page-title-main">Agent Pink</span>

Agent Pink is the code name for a powerful herbicide and defoliant used by the U.S. military in its herbicidal warfare program during the Vietnam War. The name comes from the pink stripe painted on the barrels to identify the contents. Largely inspired by the British use of herbicides and defoliants during the Malayan Emergency, it was one of the rainbow herbicides that included the more infamous Agent Orange. Agent Pink was only used during the early "testing" stages of the spraying program before 1964.

<span class="mw-page-title-main">Rainbow Herbicides</span> Herbicides used by the US in the Vietnam War

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. Herbicidal warfare is the use of substances primarily designed to destroy the plant-based ecosystem of an agricultural food production and/or to destroy dense foliage which provides the enemy with natural tactical cover.

Project Agile was an Advanced Research Projects Agency (ARPA) project in the 1960s that investigated means for engaging in remote, limited asymmetric warfare. The research was intended for use in providing U.S. support to countries engaged in fighting Communist insurgents, particularly in South Vietnam and Thailand.

The Nerepis River is a river approximately 25 miles (40 km) long in New Brunswick, Canada. A popular river for canoeists and anglers, it is a tributary of the Saint John River. The river has been subjected to significant environmental stress over many years.

Gagetown is a 2009 documentary film that looks into the massive defoliant spray program that was used at CFB Gagetown since 1956. The chemical herbicides used include 50/50 mixtures of 2,4-D/ 2,4,5-T, and Tordon 101, also known as Agent Orange and Agent White.

This is an index of articles relating to pesticides.

<span class="mw-page-title-main">2,4-Dichlorophenoxyacetic acid</span> Herbicide

2,4-Dichlorophenoxyacetic acid is an organic compound with the chemical formula C8H6Cl2O3 which is usually referred to by its ISO common name 2,4-D. It is a systemic herbicide which kills most broadleaf weeds by causing uncontrolled growth in them but most grasses such as cereals, lawn turf, and grassland are relatively unaffected.

The Enlist Weed Control System is an agricultural system that includes seeds for genetically modified crops that are resistant to Enlist and the Enlist herbicide; spraying the herbicide will kill weeds but not the resulting crop. The system was developed by Dow AgroSciences, part of Dow Chemical Company. In October 2014 the system was registered for restricted use in Illinois, Indiana, Iowa, Ohio, South Dakota and Wisconsin by the US Environmental Protection Agency. In 2013, the system was approved by Canada for the same uses.

Agent Orange is a herbicide, classified as a defoliant, that was used most notably by the U.S. military during the Vietnam War. Its primary purpose was strategic deforestation, destroying the forest cover and food resources necessary for the implementation and sustainability of the North Vietnamese style of guerilla warfare. The U.S. Agent Orange usage reached an apex during Operation Ranch Hand, in which the material was sprayed over 4.5 million acres of land in Vietnam from 1961 to 1971.

Carol Van Strum is an American environmental activist who since 1975 has fought against the spraying of herbicides, including Agent Orange, in the Siuslaw National Forest in Oregon. Her subsequent research, including over 20,000 documents revealing corporate and government cover-ups, was donated to the Poison Papers project in 2017. In 2018, Van Strum received the David Brower Lifetime Achievement Award for her contributions to forestry policy favoring selective harvest without the use of herbicides.

References

  1. 1 2 3 National Defence and the Canadian Forces: Health Information Summary for CF Members Archived 2012-12-09 at the Wayback Machine Date Modified: 2012-01-13; Subpage of DND CF The Use of Herbicides at CFB Gagetown from 1952 to Present Day Archived December 12, 2011, at the Wayback Machine Project
  2. Berufliche Akne (sog. Chlorakne) durch chlorierte aromatische zyklische Äther Von J. Kimmig und K. H. Schulz in Dermatologica Vol. 115, 1957, p.540-6 (German; with English and French summaries; cited in CA 1958:22227) (accessed 2013-07-29)
  3. Table TCDD-UNFÄLLE - Eine Bilanz des Schreckens pp. 54-59 in Seveso ist überall - Die tödlichen Risiken der Chemie by Egmont R. Koch, Fritz Vahrenholt; 1978, ISBN   3 462 012908 (accessed 2013-07-29)
  4. p. 49 in Seveso ist überall - Die tödlichen Risiken der Chemie by Egmont R. Koch, Fritz Vahrenholt; 1978, ISBN   3 462 012908
  5. Peter H. Schuck: Agent Orange on Trial: Mass Toxic Disasters in the Courts p. 17 (accessed 2013-07-29)
  6. "Chemical companies, US authorities knew dangers of Agent Orange" Archived 2016-08-22 at the Wayback Machine by Jon Dillingham; August 10, 2009 (accessed 2013-07-29)
  7. REPORT TO SECRETARY OF THE DEPARTMENT OF VETERANS AFFAIRS ON THE ASSOCIATION BETWEEN ADVERSE HEALTH EFFECTS AND EXPOSURE TO AGENT ORANGE Archived 2016-04-06 at the Wayback Machine as Reported by Special Assistant Admiral E.R. Zumwalt, Jr., May 5, 1990 (accessed 2013-07-29)
  8. Stellman, Jeanne et al. The Extent and patterns of usage of Agent Orange and other herbicides in Vietnam Nature, Vol. 422 (17 April 2003) pp. 681 - 687 (accessed 2013-07-29)
  9. Agent Orange: Herbicide Tests and Storage in the U.S. Veterans Administration Website
  10. Stellman Jeanne et al. page 682
  11. "The Use of Herbicides at CFB Gagetown from 1952 to Present Day" Archived December 12, 2011, at the Wayback Machine , Canadian Department of National Defence
  12. "Agent Orange and Agent Purple", CBC News, 21 August 2007