INSECTICIDAL VARNISHES (Latin insectum + to kill an insect with caedere) — the materials containing crystal insecticides and having long insecticidal properties; are intended for extermination of the creeping insects. — red and black cockroaches, bed bugs, red house ants, etc. in inhabited and service premises; use of this form of insecticides on vehicles is especially rational.
Varnishes (see) use as depot for dissolved insecticides (see). After drawing on a surface And. l. rather quickly dry, turning into a solid, clear film. A part of an insecticide comes to a surface and forms a plaque of crystals which are easily fixed on pads of insects.
At mechanical impact on surfaces (wiping, washing, cleaning) crystals are removed, but through a nek-swarm are allocated time from a film again. Sometimes in And. l. enter not one, but two various insecticides. One — more flying and quickly coming to a surface (for destruction of the existing insects), the second — less flying and rather slowly allocated for a surface (for the subsequent action).
K I. l. impose the following requirements: insecticidal varnish coatings shall keep well on any surfaces (the tile, plywood, iron, surfaces painted by an oil paint, etc.), without changing their outward; applied on surfaces And. l. thermo - and water proofness shall harden and possess quickly after that, and also to maintain mechanical influence; the structure of varnishes shall provide small crystallization of insecticides (the size of crystals of 5 — 10 microns) and their bystry regeneration on a surface of a lacquer film; And. l. shall possess long residual action; they shall not be toxic for the person and domestic animals, and volatile components shall disappear from rooms quickly.
As actively active ingredients in And. l. most often use GHTsG gamma isomer, etc. in number from 2 to 10%. Apply the alkyd to film formation, amide, phenolic, epoxies, diizotsionatny polyethers, etc. As solvents serve acetone, butyl acetic ether, a xylol, toluene, ethyl acetate, etc. Duration of action And. l. depends on physical. - chemical properties of an insecticide, its concentration in a varnish, film thicknesses, temperatures of the room where it is applied And. l., etc.
During the processing of rooms And. l. put with strips 3 — 10 cm wide on the ways of possible movement and places of accumulation of insects: along plinths, about heating devices, around drain sinks, at an entrance of pipes to walls, on perimeter of door boxes, along cracks in walls and furniture and other places.
Bibliography: Vashkov V. I., etc. Insecticides and their use in medical practice, M., 1965, bibliogr.; Tsetlin In, M. and In and l to about in and the p B. A. Physical and chemical factors of disinfection, M., 1969, bibliogr.
V. A. Vilkovich.