c. Types of Repellents. Some repellents are more effective for some uses
than are others. There are several formulations in the military supply system.
(1) Personal use or skin application. Repellents for personal use are
applied directly to the skin. Usually, 2.5 ml of the cream rubbed between the hands and
spread evenly over the face, neck, hands, and other exposed skin areas offers
protection for up to 12 hours, depending upon the pest species concerned. Additional
repellent may be spread on the clothing at the shoulders and other areas where the
cloth fits tightly against the body. Be careful to keep the chemical out of the eyes. The
chemical is lost from the skin by abrasion, absorption, and evaporation. The
effectiveness of the material is lost more rapidly (6 hours) in hot, humid climates where
profuse sweating occurs. Repellents that are recommended for application on the skin
may also be applied by hand or by sprayer to the outside of the clothing, if desired.
However, several special items have been developed for impregnation of clothing to
either repel or kill mites, insects, and other pests. The repellent for personal use is
DEET (30% N, N-diethyl-m-toluamide), which provides protection against all types of
mosquitoes, other biting flies, and fleas. It is relatively effective against ticks and
chiggers.
(2) Clothing application. Permethrin formulations are designed so that
clothing, bednets, tents, and tent liners can be dipped or sprayed with a solution of the
repellent chemical. A desired quality of these formulations is that treated materials be
able to withstand laundering or wetting without losing its repellent properties. The
principal requirement for a clothing treatment chemical for military use is the protection
of troops against chiggers, ticks, and leeches in many areas of the world. Detailed
directions for use of these materials vary with the specific item and with the type of
clothing being treated. Instructions issued by the local command surgeon should be
followed.
Section III. RODENTICIDES
1-8.
GENERAL
Poisoning of rodents at military installations is normally undertaken with
anticoagulants or zinc phosphides, both of which are standard rodenticides. Sodium
monofluoroacetate, a restricted use rodenticide that requires approval of the Surgeon
General for procurement and use, is a nonstandard item for emergency use. The
standard rodenticides provide adequate rodent control under a wide range of conditions.
Nonstandard items should be used only when standard items fail or are not available.
1-9.
ANTICOAGULANTS
These rodenticides are chemicals that cause internal bleeding by reducing the
clotting ability of the blood. Since all warm-blooded animals are affected in this manner,
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