eva p o r a t e s s l ow l y a t n o r m a l t e m p e r a t u r e s ;
Most of the detailed information about agent VX is
classified and cannot be covered in this text. In general,
consequently, it remains effective for a considerable
V agents are colorless and odorless liquids that do not
length of time after application. In fact, in winter
evaporate rapidly or freeze at very low temperatures.
months, HD may produce casualties for several weeks
Because of their low volatility, their vapor effect is
after dissemination. On the other hand, the warm
limited; thus, the duration of their effectiveness is
temperatures of summer, assisted by wind and rain,
increased. In liquid or aerosol form, V agents affect the
may reduce its capability to days. Almost every
body in a manner similar to that of the G agents. The
shipboard surface or material, except bright metal and
V agents usually are disseminated as liquid droplets.
glass, absorbs some mustard and retains it more or less
When inhaled, these agents are inherently about five
persistently. Regardless of weather and wind, no
times as toxic as the older nerve agents (G series).
shipboard surface contaminated with mustard should
When absorbed through the skin, the V series agents
are several hundred times more toxic than the G agents,
be considered completely free of this agent unless a
because there is no breakdown of the V agent (as there
negative test is obtained with a detector kit.
is in GB) as it passes through the fatty layer of the skin.
Because HD can be dissolved by fats, it may be
dissolved in foodstuffs and make them poisonous.
Blister Agents
Mustard can be dissolved easily in such commercial
The blister agents, used for casualty effect, may
solvents as benzene and cleaning fluid, and in motor
restrict the use of ground personnel, slow troop
oils, but it is only slightly soluble in water. On
movements, and hamper the use of material or
prolonged standing, it reacts with water to produce
installations. These agents affect the eyes and lungs
harmless substances. The action of HD on metal is very
and blister the skin, producing long-term
slight.
incapacitation or death. Blister agents are odorless and
The newer blister agents include the nitrogen
vary in duration of effectiveness. Most blister agents
are insidious in action; there is little or no pain at the
mustards HN-1, HN-2, HN-3 and the mixed blister
time of exposure (except to lewisite (L) and phosgene
agent HL. These mixtures do not produce more severe
oxime (CX), which cause immediate pain on contact).
injuries than do other agents alone, but they have a
The development of casualties is somewhat delayed;
lower freezing point than pure HD.
the effects of distilled mustard (HD) may appear in 4 to
6 hours after exposure. The first effect is eye irritation.
Blood Agents
Next, the more sensitive body parts are affected. A
series of symptoms follow, ranging from slight redness
Blood agents enter the body through the
to blistering and the forming of ulcers. Wet skin
respiratory tract. They affect bodily functions through
absorbs more mustard than dry skin. For this reason,
action on the enzyme cytochrome oxidase, thus
lower concentrations of mustard HD are needed in hot,
preventing the normal transfer of oxygen from blood to
humid weather because the body is then moist with
body tissue. Most blood agents act rapidly and are
perspiration. This fact is important in the tropics.
normally nonpersistent. In general, a victim who does
Protection from blister agents is extremely difficult,
not die quickly will recover within a few hours.
because they attack any part of the body that comes in
contact with the liquid or vapor agent.
The most common blood agents are as follows:
Hydrogen cyanide (AC)
The primary blister agents, HD and HN, are most
effective for general use. However, they are far less
Cyanogen chloride (CK)
effective than the nerve agents for casualties that result
in quick death from inhalation are, because a high
Although AC is one of the most deadly poisons
dosage of mustard vapor is required to produce death.
known, it is one of the least effective chemical agents
Mustard is effective by absorption of both vapor and
liquid through the skin. The physiological action is
because it evaporates rapidly. The vapors are less dense
localized to the area of the skin that is contaminated,
than air. They do not provide a blanket of the agent, and
but it does not produce a systemic effect.
the poisoning effects do not accumulate as exposure
continues. CK deteriorates the chemical canisters in
In the pure state, mustard is a yellowish, oily
protective masks within a short period of time.
liquid. Because of its high boiling point, liquid mustard
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