3-Quinuclidinyl benzilate (QNB) (IUPAC name1-azabicyclo[2.2.2]octan-3-yl hydroxy(diphenyl)acetate;US Army codeEA-2277;NATO codeBZ; Soviet codeSubstance 78[1]) is an odorless and bitter-tasting military-gradeincapacitating agent.[2] It impairs muscle movement and causesdelirium andhallucinations to the point of helplessness.[3]
BZ was first synthesized by the Swisspharmaceutical companyHoffman-LaRoche in 1951, which unsuccessfully tried to develop it into a treatment forgastrointestinal disease. Within a few years, theUnited States Army took it up as part of itschemical weapons program.[4] Allegations have been made that the U.S. army used it in theVietnam War.[5] The army denies this; in 1969 it officially banned the compound due to its "wide range of variability of effects, long onset time, and inefficiency of existing munitions."[3] There have also been numerous, unproven allegations of its use in Syria,[6] Bosnia[7] and Russia.[8]
BZ is a white crystalline powder with a bitter taste. It is odorless and nonirritating with delayed symptoms several hours after contact.[2][9] It is stable in most solvents, with ahalf-life of three to four weeks in moist air; even heat-producing munitions can disperse it. It is extremely persistent in soil and water and on most surfaces. BZ is soluble in water, soluble in dilute acids,trichloroethylene,dimethylformamide, and most organic solvents, and insoluble with aqueous alkali.[9][10]
Based on data from more than 500 reported cases of accidentalatropine overdose and deliberate poisoning, the median lethal oral dose is estimated to be approximately 450 mg (with a shallow probit slope of 1.8). Some estimates of lethality with BZ have been grossly erroneous, and ultimately the safety margin for BZ is inconclusive due to lack of human data at higher dosage ranges, though some researchers have estimated it to be 0.5 to 3.0 mg/kg and an LD01 is 0.2 to 1.4 mg/kg (Rosenblatt, Dacre, Shiotsuka, & Rowlett, 1977).[14]
Antidotes for BZ include 7-MEOTA, which can be administered in tablet or injection form. Atropine andtacrine (THA) have also been used as treatments, THA having been shown to reduce the effects of BZ within minutes.[15][16] Some military references suggest the use ofphysostigmine to temporarily increase synaptic acetylcholine concentrations.[2]
BZ was invented by the Swisspharmaceutical companyHoffman-LaRoche in 1951.[17] The company was investigating anti-spasmodic agents, similar totropine, for treatinggastrointestinal ailments when the chemical was discovered.[17] It was then investigated for possible use in ulcer treatment, but was found unsuitable. At this time the United States military investigated it along with a wide range of possible nonlethal, psychoactive andpsychotomimetic incapacitating agents includingpsychedelic drugs such asLSD,dissociative drugs such asketamine andphencyclidine, potentopioids such asfentanyl, as well as several glycolateanticholinergics.[4] By 1959, theUnited States Army showed significant interest in deploying it as a chemical warfare agent.[17] It was originally designated "TK", but when it was standardized by the Army in 1961, it received the NATO code name "BZ", the Chemical Corps initially referred to BZ as CS4030, then later as EA 2277.[14][17] The agent commonly became known as "Buzz" because of this abbreviation and the effects it had on the mental state of the human volunteers intoxicated with it in research studies atEdgewood Arsenal in Maryland.[17] As described in retired Army psychiatristJames Ketchum's autobiographical bookChemical Warfare: Secrets Almost Forgotten (2006), work proceeded in 1964 when a general envisioned a scheme to incapacitate an entiretrawler withaerosolized BZ; this effort was dubbedProject DORK.[18] BZ was ultimately weaponized for delivery in theM44 generator cluster and theM43 cluster bomb, until all such stocks were destroyed in 1989 as part of a general downsizing of the US chemical warfare program.
In 2022 a documentary film, Dr Delirium and The Edgewood Experiments, was broadcast onDiscovery+, featuring an interview with Ketchum not previously shown.[19]
Survivors of the 11-12 July 1995Srebrenica massacre nearTuzla during theBosnian War claimed they were attacked with a chemical agent that caused hallucinations, disorientation and strange behaviour.[20][21][22][23]
In February 1998, the BritishMinistry of Defence accusedIraq of having stockpiled large amounts of aglycolateanticholinergic incapacitating agent known as ‘Agent 15’.[24] Agent 15 is an alleged Iraqi incapacitating agent that is likely to be chemically identical to BZ or closely related to it. Agent 15 was reportedly stockpiled in large quantities prior to and during thePersian Gulf War. However, after the war theCIA concluded that Iraq had not stockpiled or weaponized Agent 15.[a][26]
In January 2013, an unidentified U.S. administration official, referring to an undisclosed U.S. State Department cable, claimed that "Syrian contacts made a compelling case that Agent 15, a hallucinogenic chemical similar to BZ,[28] was used inHoms".[29][6] However, in response to these reports aU.S. National Security Council spokesman stated,
The reporting we have seen from media sources regarding alleged chemical weapons incidents in Syria has not been consistent with what we believe to be true about the Syrian chemical weapons program.[26][6]
^ "We assess that Iraq never went beyond research with Agent 15 – a hallucinogenic chemical similar to BZ – or any other psychochemical. Agent 15 became an issue after a 9 February 1998 British press release claimed that the UK had information, thought to be reliable, that Iraq had large quantities of this chemical agent in the 1980s. UNSCOM and intelligence information indicated that Iraq researched a number of psychochemicals, including Agent 15, BZ, and PCP; however, UNSCOM indicated it saw no evidence of Iraqi importation of large quantities, weaponization, procurement of militarily significant quantities of precursors, or industrial production of these agents."[25]
^abPossible Long-Term Health Effects of Short-Term Exposure To Chemical Agents, Volume 2: Cholinesterase Reactivators,Psychochemicals and Irritants and Vesicants. (1984)
^abGupta, Ramesh C. (21 January 2015).Handbook of toxicology of chemical warfare agents (Second ed.). London: Academic Press. p. 152.ISBN978-0-12-800494-4.OCLC903965588.
^abcLevels, Committee on Acute Exposure Guideline; Toxicology, Committee on; Toxicology, Board on Environmental Studies and; Studies, Division on Earth and Life; Council, National Research (2013-04-26),"Agent BZ (3-Quinuclidinyl Benzilate): Acute Exposure Guideline Levels",Acute Exposure Guideline Levels for Selected Airborne Chemicals: Volume 14, National Academies Press (US), retrieved2025-09-11
^Ramjan KA; Williams AJ; Isbister GK; Elliott EJ (November 2007). "'Red as a beet and blind as a bat' Anticholinergic delirium in adolescents: lessons for the paediatrician".Journal of Paediatrics and Child Health.43 (11):779–780.doi:10.1111/j.1440-1754.2007.01220.x.PMID17924941.S2CID37914161.
^Lee, Martin A.; Shlain, Bruce; Codrescu, Andrei (1992).Acid dreams: the complete social history of LSD: the CIA, the sixties, and beyond (Rev. Evergreen ed.). New York: Grove Press. p. 40.ISBN978-0-8021-3062-4.
^abGoodman, Ephraim (2010).Historical contributions to the human toxicology of atropine : behavioral effects of high doses of atropine and military uses of atropine to produce intoxication. Wentzville, Missouri: Eximdyne. p. 62.ISBN978-0-9677264-3-4.OCLC858939565.
^Gupta, Ramesh C. (21 January 2015).Handbook of toxicology of chemical warfare agents (Second ed.). London: Academic Press. p. 156.ISBN978-0-12-800494-4.OCLC903965588.
^Goodman, Ephraim (2010).Historical contributions to the human toxicology of atropine: behavioral effects of high doses of atropine and military uses of atropine to produce intoxication. Wentzville, Missouri: Eximdyne. p. 72.ISBN978-0-9677264-3-4.OCLC858939565.
This article incorporatespublic domain material from websites or documents of theUnited States Army.
