Since its adoption in 1993, the Chemical Weapons Convention has banned the development, possession, and use of weaponized toxic chemicals. However, whether this prohibition also applied to law enforcement use of certain agents that act on the central nervous system (CNS) remained the subject of debate. In December 2021, Chemical Weapons Convention adopted a landmark Decision to effectively outlaw the aerosolized use of CNS-acting chemical agents for law enforcement purposes.
Although 85 countries supported the Decision, including Australia, Switzerland, and the United States, the vote was opposed by 10 countries, which may not feel constrained by its prohibitions. Notable among the opponents was Russia, whose security forces used aerosolized fentanyl derivatives to end the 2002 Moscow theater siege, causing the deaths of more than 120 hostages from poisoning and asphyxiation. Subsequent dual-use research into CNS-acting chemicals has been reported by Russian scientists as well as scientists from China and Iran, who also opposed this Decision.
Furthermore, the Decision is limited in scope. It explicitly prohibits only aerosolized CNS weapons, excluding other delivery mechanisms such as law enforcement dart guns…
Excerpt from MICHAEL CROWLEY AND MALCOLM DANDO, Central nervous system weapons dealt a blow, Science, Jan. 14, 2022