NTI: Nuclear Threat Initiative BZ
Technical Description: BZ
Based on research into atropine and other compounds in the early 1950s, it was discovered that 3-quinuclidinyl benzilate—code named “BZ,” or “agent buzz”—caused intense hallucinations when introduced in very small amounts (measured in the millionths of a gram). From its use during human experimentation with BZ, it was found that this belladonna drug causes delirious episodes. Test subjects exhibited various hallucinatory behavior, such as plucking at their own clothing (“wool gathering”), or illusionary states of consciousness during which affected individuals would play off the other’s delusions (“carphologia,” or “folie a deux”). Ditran, a related compound, has also been described as having potent hallucinatory effects, even more so than mescaline or LSD. A crystalline solid, BZ can be delivered in the form of a thermal vapor or dissolved in a solvent. The United States military prepared BZ in weaponized form at the Pine Bluff Arsenal in Arkansas. However, its unpredictability as a weapon caused it to fall out of favor, and most if not all stores of BZ were destroyed in the 1980s. As a controlled substance, BZ is a Schedule 2 toxic chemical in the Chemical Weapons Convention (CWC).

Pharmacological activity of BZ is similar to related compounds such as atropine and scopolamine, but because of its increased fat solubility, BZ has heightened effects in the central nervous system. However, BZ is only three times as potent as scopolamine, but has had a reputation for being in its own class in terms of its actual toxicity. The median incapacitating dose (ICD50) is estimated at 6.2 micrograms per kilogram, or about half a milligram for most individuals. Intoxication occurs after some delay, and the residual effects can linger for up to three days. In addition to the psychological impairment already described, vision can be seriously affected due to the anticholinergic effect of BZ and related drugs. Because these compounds can shut down sweat gland activity, affected individuals also have an increased chance of death due to heat-stroke.