3-Quinuclidinyl benzilate (QNB)
IUPAC name: 1-azabicyclo[2.2.2]octan-3-yl hydroxy(biphenyl)acetate
US Army code: EA-2277
NATO code: BZ
Soviet code: Substance 78
CAS Number: 6581-06-2
ECHA InfoCard: 100.164.060
PubChem CID: 23056
Chemical formula: C21H23NO3
Molar mass: 337.41 g/mol
Melting point: 164-165 °C
Boiling point: 322 °C
3-Quinuclidinyl benzilate is an odorless military incapacitating agent.
BZ was invented by the Swiss pharmaceutical company Hoffman-LaRoche in 1951. The company was investigating anti-spasmodic agents, similar to tropine, for treating gastrointestinal ailments when the chemical was discovered. 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 incapacitating agents including psychedelic drugs such as LSD and THC, dissociative drugs such as ketamine and phencyclidine, potent opioids such as fentanyl, as well as several glycolate anticholinergics. By 1959 the United States Army showed significant interest in deploying it as a chemical warfare agent.
It was originally designated “TK”, but when it was standardized by the Army in 1961 it received the NATO code name “BZ”. 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 at Edgewood Arsenal in Maryland.
As described in retired Army psychiatrist James Ketchum’s autobiographical book Chemical Warfare: Secrets Almost Forgotten (2006), work proceeded in 1964 when a general envisioned a scheme to incapacitate an entire trawler with aerosolized BZ; this effort was dubbed Project DORK.
BZ was ultimately weaponized for delivery in the M44 generator cluster and the M43 cluster bomb, until all such stocks were destroyed in 1989 as part of a general downsizing of the US chemical warfare program.
In February 1998, the British Ministry of Defence accused Iraq of having stockpiled large amounts of a glycolate anticholinergic incapacitating agent known as Agent 15. Agent 15 is an alleged Iraqi incapacitating agent that is likely to be chemically either identical to BZ or closely related to it. Agent 15 was reportedly stockpiled in large quantities prior to and during the Persian Gulf War. However, after the war the CIA concluded that Iraq had not stockpiled or weaponised Agent 15.
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, was used in Homs”. However, in response to these reports U.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”. The chemical was also allegedly used in the August 2013 Ghouta attacks.
The U.S. Army tested BZ as well as other “psycho-chemical” agents on human subjects at Edgewood Arsenal in Maryland from 1955 to 1975, according to declassified documents.
According to the Russian minister of foreign affairs Sergey Lavrov, a Swiss laboratory analysing the samples detected the presence of BZ and its precursors in the substance used in the Sergei and Yulia Skripal’ poisoning case. There is no independent corroboration of this and the Swiss Spiez Laboratory has referred enquries back to the OPCW and confirmed that Porton Down’s initial detection of an organophosphate nerve agent of the Novichok type was involved in the Salisbury samples.
BZ is odorless. It is stable in most solvents, with a half-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. It is slightly soluble in water; soluble in dilute acids, trichloroethylene, dimethylformamide, most organic solvents, insoluble with aqueous alkali.
Mechanism of action
The characteristic that makes BZ an incapacitating rather than a toxic chemical warfare agent is its high safety margin (ICt50/LCt50) of around 40-fold (range 32 to 384 fold). It has an ID50 of 0.00616 mg per person (i.v.) with a probit slope of 9.2. The respiratory ICt50 (median incapacitating dosage) for BZ is 110 mg·min/m³ (mild activity—15 l/min rate of breathing), whereas the LCt50 is often estimated to be around 3,800–41,300 mg·min/m³.
Detection and protection
BZ is odorless and nonirritating with delayed symptoms several hours after contact.
3-Quinuclidinyl Benzilate is synthesized from the methyl ester of benzilic acid by reaction with sodium metal in toluene followed by reaction with 3-quinuclidinol.
Russia: Swiss lab analysis shows nerve agent designed in West
Associated Press, April 14, 2018
MOSCOW — Russia’s foreign minister says Moscow has received a document from a Swiss lab that analyzed the samples in the nerve agent poisoning of an ex-Russian spy, which points at a Western-designed nerve agent as a likely cause.
Minister Sergey Lavrov said Saturday that Moscow received the confidential information from the laboratory in Spiez, Switzerland, that analyzed samples from the site of the March 4 poisoning of Sergei Skripal and his daughter in the English city of Salisbury.
He said the analysis was done at the request of the Organization for the Prohibition of Chemical Weapons.
The OPCW’s report confirmed British findings that the Skripals were poisoned with a military-grade nerve agent, but didn’t say who was responsible.
Britain has accused Russia of poisoning them with a Soviet-designed agent, an accusation that Moscow denies.
Lavrov said the document indicated that the samples from Salisbury contained BZ nerve agent and its precursor. He said BZ was part of chemical arsenals of the U.S., Britain and other NATO countries, while the Soviet Union and Russia never developed the agent.
Lavrov added that the Swiss lab also pointed at the presence of the nerve agent A234 in the samples, but added that the lab noted that its presence in the samples appeared strange, given the substance’s high volatility and the relatively long period between the poisoning and the sample-taking.
He noted that OPCW’s report didn’t contain any mention of BZ, adding that Russia will ask the chemical weapons watchdog for an explanation.
Britain said that the A234 agent belonged to the family of Soviet-designed nerve agents dubbed Novichok.
Yulia Skripal, 33, was released from the hospital this week. Her father remains hospitalized but British health officials say he is improving.