Section I. PESTICIDE FORMULATIONS
TECHNICAL GRADE PESTICIDES
A technical grade pesticide is the basic toxic ingredient in its purest commercially
available form. This material is rarely chemically pure. Technical grade diazinon, for
example, contains only about 94 to 97 percent of the active chemical. However,
technical grade pesticides are, in general, much too toxic for safe handling in the field.
Standard military pesticides are generally technical grade pesticides that have been
diluted with appropriate carriers or diluents.
REASONS FOR PESTICIDE MIXING
The concentrated forms of pesticides (restricted use) included on the military
stock list, while generally less toxic than technical grade materials, are nevertheless
highly concentrated in many cases. Examples are carbaryl, 80% powder; naled, 85%
solution concentrate; and malathion, 95% solution concentrate. Some of these
chemicals must be diluted before application, for obvious reasons. Such strong
formulations would pose a severe hazard, not only to man, but also to nontarget
organisms such as fish and other wildlife, domestic animals, beneficial insects
(honeybees, predators, etc.), agricultural crops, ornamental plants, and other desirable
forms of life. If safety were the only consideration, it would be desirable to issue every
pesticide in a ready-mixed, ready-to-use formulation. For those pesticides that are
considered general use items, this is the case. These items are prepared for individual
and small-unit use and are in formulations of very low concentrations, very small
quantities, or both. However, there are valid reasons for issuing pesticides in
concentrated form for further dilution in the field.
a. Economy in Shipping. Requirements for shipping and storing pesticides
are more stringent than are those for storing and shipping the diluents that are used to
dilute them to a strength that is safe for application. Moreover, the diluent is often
available from local sources and need not be shipped. For example, a 55-gallon drum
of 95% malathion solution concentrate, when mixed with No. 2 fuel oil, will provide
enough active material for approximately 870 gallons of 6% malathion spray for outdoor
space treatment against mosquitoes. If this amount of spray were mixed prior to
shipping, it would require 16 times as much shipping space and weight.
b. Flexibility in Application. Using concentrated pesticides to prepare
diluted mixtures enables the pest control operator to vary the strength according to the
target pest, the type of equipment used, and the rate of application.
A dust is a dry mixture that usually consists of an active pesticide mixed with talc,
clay, or some other inert powder used as a diluent, or carrier. Dusts are usually the