a.    Physiological Action.
(1)    Nerve agents (anticholinesterase) (such as Tabun (GA), Sarin (GB), Soman (GD), GF, and V-agent (VX)) inhibit the cholinesterase enzymes. The cholinesterase enzymes are responsible for the hydrolysis of acetylcholine, a chemical neurotransmitter. This inhibition creates an accumulation of acetylcholine at a cholinergic synapse that disrupts the normal transmission of nerve impulses. Cholinergic synapses are located

• In the central nervous system (CNS).
• In the neuromuscular endplates of the peripheral voluntary nervous system.
• At the parasympathetic endings and sympathetic presynaptic ganglia of the autonomic nervous system.

(2)   Blister agents (vesicants) include sulfur mustard (H/HD) and nitrogen mustard (HN), arsenicals (lewisite (L)), and phosgene oxime (CX). Blister agents produce pain and injury to the eyes, reddening and blistering of the skin, and when inhaled, damage to the mucous membranes and respiratory tract. Mustard may produce major destruction of the epidermal layer of the skin.

(3)   Lung-damaging agents (choking agents) include phosgene (CG), diphosgene (DP), chlorine, and chloropicrin (PS). These agents produce injury to the lungs and irritation of the eyes and the respiratory tract. They may also cause intractable pulmonary edema and predispose to secondary pneumonia.   

(4) (4) Blood agents (cyanogens) include hydrogen cyanide (AC) and cyanogen chloride (CK). These agents are transported by the blood to all body tissues where the agent blocks the oxidative processes, preventing tissue cells from utilizing oxygen. The CNS is especially affected and leads to cessation of respiration followed by cardiovascular collapse.   

b.    Military Use.

(1) (1) Toxic chemical agents produce serious injury or death. They include nerve agents, blister agents, lung-damaging agents (choking agents), and blood agents.

(2) Incapacitating agents produce temporary physical or mental effects, or both.