Diazinon granule

The pure chemical (100% diazinon) is a colorless and practically odorless oil. Preparations used in agriculture and by exterminators contain 85-90% diazinon and appear as a pale to dark-brown liquid. This form of diazinon is diluted with other chemicals before use. The diazinon available for home and garden use contains 1-5% diazinon in a liquid or as solid granules. These preparations have a slight chemical odor but cannot be identified by smell. Most of the diazinon used is in liquid form, but it is possible to be exposed to the chemical in a solid form. Diazinon does not bum easily and does not dissolve easily in water. It will dissolve in alcohol or other organic solvents such as petroleum products. Its basic physical and chemical properties are summarized in Chapter 3 for more information on its production and use, see Chapter 4. 

It is important to know the concentration of insecticide on the label. For dry formulations such as WPs, dusts, and granules, the insecticide concentration is expressed in percentage of active ingredient (AI) in the formulation. For example, Diazinon 50W means that 50% of diazinon is in the WP formulation. On the other hand, for liquid formulations such as solutions and emulsifiable concentrates, the concentration of insecticide is expressed in pounds of Al/gal of the formulation. For example, Diazinon 4E means that 4 lb of diazinon is in each gallon of the formulation. 

The most well-known heterocyclic derivative is diazinon which has widespread application as a contact insecticide and acaricide (see below). It is used against flies and a wide range of sucking and leaf-eating insects. Soil half-life is about 3-6 months, whereas that of malathion is about 1-2 weeks. It is utilised both as a foliage spray and in soil granule formulations. Diazinon can be used for seed treatment. 

A coated granule containing a solid (carbofuran) and a liquid (diazinon) insecticide is to be prepared. The solid inseeticide is ground to a fine powder the liquid inseeticide is sprayed onto an absorbent silica. A combination of two adhesives is used. Granular (0.4-0.8 mm) quartz is first sprayed with a liquid polyurethane while tumbling the quartz in a shell blender. Once the mass is wetted the inseetieide powders are added. After tumbling the mass to adhere the powders, an aqueous solution of polyvinyl alcohol is sprayed onto the surface. In order to set the adhesive the mass is transferred to a drier and heated to about 60°C. 

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