{{short description|Herbicide and defoliant}} {{Use American English|date=May 2026}} [[File:UC-123B Ranch Hand spraying 1962.jpg|thumb|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.<ref name='forces'>National Defence and the Canadian Forces: [http://www.forces.gc.ca/site/reports-rapports/defoliant/hinfo2-eng.asp Health Information Summary for CF Members] {{Webarchive|url=https://web.archive.org/web/20121209061705/http://www.forces.gc.ca/site/reports-rapports/defoliant/hinfo2-eng.asp |date=2012-12-09 }} Date Modified: 2012-01-13; Subpage of DND CF [http://www.forces.gc.ca/site/reports-rapports/defoliant/index-eng.asp The Use of Herbicides at CFB Gagetown from 1952 to Present Day] {{webarchive|url=https://web.archive.org/web/20111212011559/http://www.forces.gc.ca/site/reports-rapports/defoliant/index-eng.asp |date=December 12, 2011 }} Project</ref> 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).<ref name='forces' /> The Agent Purple had then the following composition: 50% 2,4-D ''n''-butyl ester, 30% 2,4,5-T ''n''-butyl ester, and 20% 2,4,5-T isobutyl ester.<ref name='forces' /> {{multiple image | align = center | total_width = 600 | header = Chemical structures of Agent Purple components | image1=Butyl 2,4-dichlorophenoxyacetate.svg | caption1=2,4-D ''n''-butyl ester | image2=Butyl (2,4,5-trichlorophenoxy)acetate.svg | caption2=2,4,5-T ''n''-butyl ester | image3=Isobutyl (2,4,5-trichlorophenoxy)acetate.svg | caption3=2,4,5-T ''iso''-butyl ester | footer = }}

Even prior to [[Operation Ranch Hand]] (1962-1971) it was known<!--not to the general public, but (peer-reviewed/scientific..) *published* in 1957:--><ref name="KIMMIG">[http://www.cbgnetwork.org/downloads/Entdeckung_Dioxin1957.pdf Berufliche Akne (sog. Chlorakne) durch chlorierte aromatische zyklische Äther] {{Webarchive|url=https://web.archive.org/web/20160322021806/http://www.cbgnetwork.org/downloads/Entdeckung_Dioxin1957.pdf |date=2016-03-22 }} Von J. Kimmig und K. H. Schulz in ''Dermatologica'' Vol. 115, 1957, p.540-6 (German; with English and French summaries; cited in [[Chemical Abstracts Service|CA]] 1958:22227) (accessed 2013-07-29)</ref><!--and known, for certain, to the perpetrators/'responsibles', i.e. chemical companies: from accidents:--><ref name="TCDD.accs">[http://www.cbgnetwork.org/downloads/Artikel_Dioxin.pdf Table TCDD-UNFÄLLE - Eine Bilanz des Schreckens] {{Webarchive|url=https://web.archive.org/web/20160322021800/http://www.cbgnetwork.org/downloads/Artikel_Dioxin.pdf |date=2016-03-22 }} pp.&nbsp;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)</ref><!--and from warning from Boehringer, 1957:--><ref name="TCDD.warn">p.&nbsp;49 in ''Seveso ist überall - Die tödlichen Risiken der Chemie'' by Egmont R. Koch, Fritz Vahrenholt; 1978, {{ISBN|3 462 012908}} </ref><!--known to US authorities already from warning by Monsanto in 1952(!):--><ref>Peter H. Schuck: [https://books.google.com/books?id=waTdqLYCyPMC&pg=PA17 Agent Orange on Trial: Mass Toxic Disasters in the Courts] p.&nbsp;17 (accessed 2013-07-29)</ref><!--and known to the military:--><ref name="TCDD.Clary">[http://thewe.cc/weplanet/asia/vietnam/agent_orange_victims_of-US_herbicide_spraying_vietnam.htm "Chemical companies, US authorities knew dangers of Agent Orange"] {{Webarchive|url=https://web.archive.org/web/20160822225545/http://thewe.cc/weplanet/asia/vietnam/agent_orange_victims_of-US_herbicide_spraying_vietnam.htm |date=2016-08-22 }} by Jon Dillingham; August 10, 2009 (accessed 2013-07-29)</ref><ref name="ZumwaltReport">[http://www.bluewaternavy.org/navydocs/Zumwaltreport.pdf REPORT TO SECRETARY OF THE DEPARTMENT OF VETERANS AFFAIRS ON THE ASSOCIATION BETWEEN ADVERSE HEALTH EFFECTS AND EXPOSURE TO AGENT ORANGE<!--CAPS in Orig.-->] {{Webarchive|url=https://web.archive.org/web/20160406093737/http://bluewaternavy.org/navydocs/Zumwaltreport.pdf |date=2016-04-06 }} as Reported by Special Assistant Admiral E.R. Zumwalt, Jr., May 5, 1990 (accessed 2013-07-29)</ref> 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. [[Polychlorinated dibenzodioxins|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.<!-- <ref name="Stellman"></ref> --> A 2003 ''[[Nature (journal)|Nature]]'' paper by Stellman et al., which re-apprised the average TCDD content of Agent Orange from the 3&nbsp;[[parts per million|ppm]] that [[USAF]] had reported to a level of 13&nbsp;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&nbsp;ppm TCDD.<ref name="Stellman">Stellman, Jeanne et al. [http://stellman.com/jms/Stellman1537.pdf 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)</ref>

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.<ref>Agent Orange: Herbicide Tests and Storage in the U.S. [http://www.publichealth.va.gov/exposures/agentorange/outside_vietnam_usa.asp Veterans Administration Website]</ref> About {{convert|500,000|U.S.gal|abbr=on}} were sprayed in Vietnam in total.<ref>Stellman Jeanne et al. page 682</ref> 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.<ref>[http://www.forces.gc.ca/site/reports-rapports/defoliant/index-eng.asp "The Use of Herbicides at CFB Gagetown from 1952 to Present Day"] {{webarchive |url=https://web.archive.org/web/20111212011559/http://www.forces.gc.ca/site/reports-rapports/defoliant/index-eng.asp |date=December 12, 2011 }}, Canadian Department of National Defence</ref><ref>[http://www.cbc.ca/news/background/agentorange/ "Agent Orange and Agent Purple"], CBC News, 21 August 2007</ref>

==References== {{Reflist}}

{{Rainbow Herbicides}}

[[Category:Auxinic herbicides]] [[Category:Defoliants]] [[Category:Military equipment of the Vietnam War]] [[Category:Canada and the Vietnam War]]