Introduction and Background
Description of the Chemical Agent and Munitions Stockpile
more than 50 years, the United States has maintained a stockpile of
chemical agents and munitions distributed among eight sites within the
continental United States and at Johnston Atoll in the Pacific Ocean.
Two basic types of chemical agents comprise the stockpile: neurotoxic
(nerve) agents and mustard (blister) agents. Both types are frequently,
and erroneously, referred to as "gases" even though they are liquids at
normal temperature and pressure.
agents include the organic phosphorus compounds designated as VX, GB
(Sarin), and GA (Tabun). These chemicals present a significant toxic
hazard because of their action on the nervous systems of humans and
animals through inhibition of the acetyl-cholinesterase enzyme. They
are both considered extremely toxic. VX is more acutely toxic than GB,
but the latter represents a greater potential hazard because of its
higher volatility (about the same as water) and, thus, the greater
likelihood of its being inhaled. Chronic health effects and cancer from
low-level exposures have not been associated with nerve agents or with
chemically (and toxicologically) similar commercially available organic
phosphorus insecticides (Leffingwell, 1993). Only short-term symptoms
have been documented in individuals who survive exposure to nerve
The mustards (designated H
[nondistilled mustard], HD [distilled mustard], and HT [thickened
mustard]) do not present significant acute lethal hazards. Their
principal effect is severe blistering of the skin and mucous membranes.
They have been implicated as being carcinogenic, however, and may
present a cancer hazard to individuals exposed acutely (Leffingwell,
1993; IOM, 1993). The estimates for induced cancers from accidental
agent exposures only consider mustard agents.
agents, after being fully dispersed, do not tend to persist in the
environment because their relatively simple chemical structures tend to
undergo hydrolysis in humid climates. However, in extremely dry desert
climates, they can remain for a considerable period of time (U.S. Army,
The chemical agents in the U.S.
stockpile are stored in a variety of containment systems, including
bulk (ton) containers, rockets, projectiles, mines, bombs, cartridges,
and spray tanks. Figure 1-1
summarizes the stockpile configuration as of 1996 for the eight
continental U.S. sites by agent, munition, and containment system (OTA,
1992; NRC, 1996a).