GB668468A - New or improved compositions for the generation of smokes of vaporisable pest control compounds - Google Patents

Abstract

668,468. Pesticidal fumigants. MARKE, D. J. B., and IMPERIAL CHEMICAL INDUSTRIES, Ltd. Jan. 5, 1950 [Jan. 5, 1949], No. 261/49. Class 81 (i). A fumigating composition comprises a thermally vapourizable pest control compound, substantially stoichiometrically equivalent quantities of a nitrite of an alkali metal of atomic weight not exceeding 40 and an ammonium salt of an inorganic acid, and a stabilizer capable of delaying the reaction occurring on storage between the nitrite and the ammonium salt, the nitrite and the ammonium salt being present in sufficient amounts to render the composition capable of propagating through itself at ordinary atmospheric pressure an exothermic reaction when initiated by local heating. Equivalent quantities of ammonium chloride or sulphate with sodium nitrite may be employed. Specified stabilizers are anhydrous sodium sulphate or carbonate, ammonium carbonate, magnesium oxide, carbonate or basic carbonates, zinc oxide or carbonate, and calcium oxide or carbonate. The pest control compounds may be liquids such as nicotine, ortho-dichlorbenzene, hexa-ethyl tetra-phosphate, diethyl para nitrophenyl thiophosphate, isobornyl thio-cyano-acetate, or dimethyl phthalate preferably adsorbed on a carrier such as china clay or kieselguhr or solid pest control compounds such as naphthalene, azobenzene, pentachlorophenol, gamma - hexachloro - cyclohexane or D.D.T. Preferably the pest control compound is mixed with the previously prepared pulverulent or granular mixture of nitrite, ammonium salt and stabilizer. The composition may be embodied in a cartridge comprising a container normally sealed against the entry of moisture. The container preferably has a restricted gas outlet. Reference has been directed by the Comptroller to Specification, 631,114.