Threat of non-traditional agents: a new frontier in chemical weapons concerns?

The development and use of chemical and toxin-based weapons have evolved significantly over time, from early historical applications to modern incidents involving highly potent agents. Despite the establishment of international treaties such as the Chemical Weapons Convention (CWC) and the Biological and Toxin Weapons Convention (BTWC), emerging threats posed by non-traditional agents, particularly central nervous system (CNS)-acting chemicals and biotoxins, present ongoing challenges. These substances, while not individually scheduled, fall within the broader definitions of toxic chemicals and are prohibited if used for purposes inconsistent with the conventions.CNS-acting chemicals, including pharmaceutical-based agents such as fentanyl analogues and alpha-2 adrenergic agonists, raise concerns due to their incapacitating or lethal effects, potential misuse in law enforcement contexts and increasing availability via illicit markets. Biotoxins such as ricin and saxitoxin, although naturally derived, have military relevance and are subject to regulation under both the CWC and BTWC.This analysis synthesises key developments that have shaped the current threat landscape and explores the challenges these agents pose for both verification mechanisms and military medical preparedness. It highlights gaps in toxidrome identification, limitations in available countermeasures and the need for improved diagnostic capabilities, all of which are critical for mitigating the risks associated with exposure to non-traditional agents.