CHEMICAL AGENTS AND PROTECTION FROM CHEMICAL AGENTS
TYPES OF CHEMICAL AGENTS
A chemical agent is a chemical substance intended for use in military operations
to kill, seriously injure, or incapacitate personnel through its toxicological (poisonous)
effects. Chemical agents may be inhaled as a vapor, ingested when food or water
contaminated by the agent is consumed, or absorbed when the agent comes into
contact with the skin or eyes. The four primary types of chemical agents are nerve
agents, blood agents, blister agents, and choking (lung-damaging) agents.
Incapacitating agents and vomiting agents are also considered to be chemical agents.
All six types of chemical agents are deadly if the casualty is exposed to a sufficient
concentration. A chemical agent may be used by itself or in combination with other
chemical agents. Your protective mask and protective clothing provide good protection
against all chemical agents. Chemical agents may be classified as being persistent or
a. Persistent. Persistent chemical agents continue to present a hazard for a
considerable period of time after delivery. They are usually released as solids or
liquids. Persistent agents remain as a contact hazard or vaporize very slowly to
produce a dangerous vapor.
b. Nonpersistent. Nonpersistent chemical agents present a hazard for only a
short period of time after delivery. They can be aerosols, gases, vapors, liquids, or
solids. Nonpersistent agents dissipate or vaporize rapidly after release and present an
immediate, short duration hazard.
Nerve agents are among the deadliest chemical agents. These agents directly
affect the human nervous system. If the person is exposed to a sufficient amount of
nerve agent (either high concentrations for a short period of time or low concentrations
over a longer period of time), the diaphragm and the intercostal muscles of the chest
become paralyzed. The paralysis of these muscles results in the casualty not being
able to inhale and exhale. Respiratory failure leads to cardiac arrest (heart ceases to
pump blood) and death.
a. Types of Nerve Agents. Nerve agents are divided into two major groups:
the G-agents and the V-agents. Examples of the G-agents are GA (Tabun), GB (Sarin),
and GD (Soman). O-ethyl s-(2 diisopropyl amiono ethyl) methylphosphonothiolate
[nerve agent](VX) is an example of a V-agent.
b. Methods of Dissemination. Nerve agents can be dispersed by artillery
shell, mortar shell, rocket, aircraft bomb or bomblet, missile, spray, or land mine. Nerve
agents can be disseminated as a vapor (spray or aerosol droplets) or liquid.