Which of the following is the most toxic nerve agent?

VX is recognized as the most toxic nerve agent among the listed options. It is a synthetic compound originally developed for use as a pesticide and has since been utilized as a chemical weapon due to its extreme potency. VX can be lethal in very small doses, affecting the body’s ability to regulate essential functions, leading to respiratory failure and eventually death.

The toxicity of VX arises from its mechanism of action; it inhibits the enzyme acetylcholinesterase, resulting in an accumulation of acetylcholine, which causes continuous stimulation of muscles, glands, and the central nervous system. This can lead to convulsions and paralysis. In terms of its lethal dose, VX is significantly more potent than other nerve agents such as Sarin and Tabun, which, while also deadly, require a higher exposure level to reach toxic effects.

Understanding the differences in toxicity among these agents is crucial for emergency responders like firefighters, particularly those operating in HAZMAT scenarios, as it informs their response strategies and safety measures in the presence of such chemical threats.