MIL-HDBK-783(EA)
CHAPTER 2
CONTAMINANTS
Chemical and biological (CB) warfare agents represent a very significant threat to the effective performance
of military operations. CB agents can kill or incapacitate the soldier or seriously degrade his performance.
Unprotected or inadequately protected personnel who are exposed to CB agents can suffer a range effects
including skin irritation, sickness, disorientation, and death. Chemical agents can also contaminate and affect
the performance of equipment that the soldier must rely on to function effectively. The agents and effects are
described in pars. 2-2 and 2-3. A threat overview, given in par. 2-4, discusses agent delivery and dissemination
systems and techniques. The chemical and biological hazards associated with agent delivery are also described.
2-1 INTRODUCTION
criteria used to select suitable agents are
CB agents have a range of effects on unprotected
1. Toxicity in extremely small concentrations
personnel. Some agents cause mild irritation, sickness,
2. Toxicity through various routes of entry into the
and physical and mental degradation that diminish a
body
soldier's willingness to fight or impair his fighting skills.
3. Time required for onset of symptoms and duration
Other, more lethal, agents can have rapid and devastating
of effect
effects. The severity of the effect of a CB agent on exposed
4. Long-term storage stability
personnel depends upon the entry route into the body as
5. Ease of dissemination in practical munitions
well as the dosage and type of agent. CB agents can enter
6. Low cost (Ref. 1).
the body through a number of routes: the respirator
Chemical agents may be classified according to their
tract, the eyes, lesions on the skin, ingestion, and direct
chemical structure, physical and chemical properties, and
absorption through the skin.
mode of action. They also may be classified as persistent
CB agents can be dispersed by bombs, artillery rounds.
rockets. grenades, land mines, and missiles. Additionally,
or nonpersistent depending on the length of time they
remain on surfaces. Generally. the effects of chemical
CB agents can be sprayed from land vehicles, fixed-wing
agents are acute, that is, the poisoning symptoms appear
aircraft, and helicopters. The agents are disseminated in
vapor, aerosol, or liquid droplet form. Vapor and aerosol
within minutes to hours.
There are two categories of biological agents: micro-
forms can be readily and rapidly dispersed. They can
organisms and toxins. Microorganisms include bacteria,
easily penetrate buildings and vehicles through crevices,
rickettsias, viruses, and fungi. Because of the incubation
cracks, and small openings. Because of this insidious
penetration. protection of personnel becomes a formidable
period required for the particular disease to spread
throughout the body and for the onset of symptoms,
task. Even if the personnel are fully protected by wearing
protective gear, many gaseous, i.e.. vapor and aerosol,
microorganisms are considered delayed incapacitating or
lethal agents. However, the delay period will be shortened
agents can saturate the filters of respiratory devices and
render them useless. Liquid agents can gradually penetrate
and the symptoms can be much more severe than those of
through protective gear to reach the skin and cause a
normal infection by the same species of microorganism if
contact hazard. Furthermore, continuous wearing of the
a very large dose of agent has entered the body. A mixture
of two or more microorganisms can produce complex
protective overgarment and other protective gear will
pathological effects. Furthermore, if agents that cause
degrade mission performance due to the cumbersome
contagious diseases are employed, a disease can spread to
nature of the gear and the thermal burden it imposes on
the body. The use of CB agents before launching an attack
cause an epidemic.
with traditional weapons can be a decisive factor in the
Toxins, the secretions or metabolic products of living
organisms, i.e., animals, plants, and microorganisms, can
battle because defensive forces are likely to be so weakened
that that are unable to defend their positions or to
be isolated and stored in munitions. Similar to chemical
counterattack.
agents, toxins can produce immediate and acute toxic
Chemical agents are synthesized chemicals. Although
effects. The extent of the effects depends on the dosage
thousands of chemical agent candidates have been
and type of toxin. Some toxins have a cumulative effect,
designed and tested for military use, only a few have been
i.e., prolonged low-level exposure can result in the same
toxic effect as short exposure at a higher level.
found to be of practical military value. Some of the
2-1
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