. Vomiting agents, which induce vomiting,
but which also are of very short duration.
Chemical agents may also be classified as
lethal or nonlethal. Lethal agents are those that
result in a 10 percent or greater death rate among
casualties. They may further be classified as per-
sistent or nonpersistent, depending on the length
of time they retain their effectiveness after
Physically, nerve agents are odorless, almost
colorless liquids varying greatly in viscosity and
volatility. They are moderately soluble in water
and fairly stable unless strong alkali or
chlorinating compounds are added. They are very
effective solvents readily penetrating cloth either
as a liquid or vapor. Other materials, including
leather and wood, are fairly well penetrated. Butyl
rubber and synthetics, such as polyesters, are
much more resistant.
the nerve agents are
cholinesterase inhibitors. Their reaction with
cholinesterases is irreversible; consequently, the
effects of inhibition are prolonged until the body
synthesizes new cholinesterases.
Signs and Symptoms of Exposure
Nerve agent intoxication can be readily iden-
tified by its characteristic signs and symptoms. If
a vapor exposure has occurred, the pupils will con-
strict, usually to a pinpoint; if the exposure has
been through the skin, characteristic local
muscular twitching will occur.
Other symptoms will include rhinorrhea,
dyspnea, diarrhea and vomiting, convulsions,
hypersalivation, drowsiness, coma, and
Specific therapy for nerve agent casualties is
atropine, an acetylcholine blocker. For immediate
self-aid or first aid, each individual is issued three
automatic injectors containing 2 mg of atropine
sulfate for intramuscular injection or two autoin-
jectors containing the Nerve Agent Antidote.
These injectors are designed to be used by in-
dividuals on themselves when symptoms appear.
After the first injection, if the symptoms have not
disappeared within 10 to 15 minutes, another in-
jection should be given. If the symptoms still
persist after an additional 15 minutes, a third in-
jection may be given by nonmedical personnel.
For medical personnel, the required therapy
is to continue to administer atropine at 15-minute
intervals until a mild atropinization occurs. This
can be noted by tachycardia and a dry mouth.
Atropine alone will not relieve any respiratory
muscle failure. Prolonged artificial respiration
may be necessary to sustain life.
Oxime therapy, using pralidoxime chloride, or
2-PAM Cl, may also be used for regeneration of
the blocked cholinesterase. For individuals treated
initially with the new autoinjector, additional ox-
ime therapy is generally not medically indicated;
it is already included in the autoinjector.
Blister agents or vesicants exert their primary
action on the skin, producing large and painful
blisters that are incapacitating. Although vesicants
are classed as nonlethal, high doses can cause
Common blister agents include mustard (HD),
nitrogen mustard (HN), and Lewisite (L).
Although each is chemically different and will
cause significant specific symptoms, they are all
sufficiently similar in their physical characteristics
and toxicology to be considered as a group.
Mustards are particularly insidious because they
do not manifest their symptoms for several hours
after exposure. They attack the eyes and respir-
atory tract as well as the skin. Further, there is
no effective therapy for mustard once its effects
become visible. Treatment is largely supportive,
to relieve itching and pain and to prevent
Mustard (HD) and Nitrogen Mustard
HD and HN are oily, colorless or pale yellow
liquids, sparingly soluble in water. HN is less
volatile and more persistent than HD and has the
same blistering qualities.
SYMPTOMS. The part of the body most
vulnerable to mustard gas is the eyes. Contamina-
tion insufficient to cause injury elsewhere may
produce eye inflammation. Vapor or liquid may
burn any area of the skin, but the burns will be
most severe in the warm, sweaty areas of the body;
that is, the armpits, groin, and on the face and
neck. Blistering begins in about 12 hours but may
be delayed for up to 48 hours. Inhalation of the gas