Which nerve agent is the most persistent, is the most oily, and will stay active in an area for several days?

Which nerve agent is the most persistent, is the most oily, and will stay active in an area for several days?

• A. VX
• B. Sarin
• C. Soman
• D. Tabun

Answer: (A)

Nerve agent persistence is driven by volatility and lipophilicity. The more oily and less volatile the molecule, the longer it will linger on surfaces and in an environment. VX is extremely lipophilic and has very low vapor pressure, so it forms residues that stay active for days in many conditions. That combination makes VX the most persistent and oily among common nerve agents, capable of remaining in an area for several days. In contrast, sarin is highly volatile and evaporates quickly, soman degrades faster than VX, and tabun sits in between; these properties lead to shorter environmental persistence.

Nerve agent persistence is driven by volatility and lipophilicity. The more oily and less volatile the molecule, the longer it will linger on surfaces and in an environment. VX is extremely lipophilic and has very low vapor pressure, so it forms residues that stay active for days in many conditions. That combination makes VX the most persistent and oily among common nerve agents, capable of remaining in an area for several days. In contrast, sarin is highly volatile and evaporates quickly, soman degrades faster than VX, and tabun sits in between; these properties lead to shorter environmental persistence.