EGG-KILLERS (Latin ovum egg + to kill with caedere) — the substances capable to kill eggs of helminths (helminths) and insects in the environment.
Pernicious action concerning eggs of helminths connections, various by the chemical nature, possess: phenol and its derivatives (pentachlorsodium phenylate, carbolic to - that), strong spiria, acids (nitric, sulfuric), alkalis, dry chloric and quicklime, thio-zones, karbation, acetone, iodine, methyl and methyl bromide and ethyl, chloroform, derivatives carbamic and isocyanic to - t, etc.; from gases — ammonia, carbon sulfur, methane, acetone, vapors of formaldehyde.
Mechanism of action The lake, physical relating to various chemical groups and possessing various. - chemical properties, it is studied insufficiently. It is established that considerable resistance of eggs of helminths to influence of chemical factors is explained by existence in their shell of a semipermeable cover of the lipoid nature, edges passes only the substances dissolving lipoida or which are dissolved in them. In this regard O. on the mechanism of action can be subdivided into two groups: The lake, action to-rykh is connected with destruction of all covers of a shell (carbolic to - that, benzylchlorphenol, etc.), and O. destroying outside covers of a shell and dissolving lipoprotein and lipoid components of its internal covers (caustic soda, etc.).
Routes of administration Lakes depend on their aggregate state and character of the processed objects. E.g., gaseous O. (anhydrous ammonia) apply to disinfecting of sewage, rainfall of dead waters, manure only in the closed tanks; powdery (thiozones) and liquid (solutions of phenol, a karbation, a thiozone, etc.) — for drawing on surfaces of firm objects (a floor, walls, the soil) and hashing with the processed substrate (sewage, a deposit of sewage, manure, etc.) in mixing drums.
Degree of ovitsidny effect of chemical substances depends on character and physical. - chemical properties of the processed substrate, in Krom there are eggs, from concentration and a dose of drug, from climatic factors (temperature, humidity, etc.), depths of finding of eggs, exposure and a way of processing. E.g., thiozones, brought in the soil covered with a film in a dose of 200 g/kg (in a hotbed), on exposure of 10 days causes in a surface layer to 2 cm death of 100% of eggs of ascarids of pigs, at a depth of 10 cm — 87,8%, and in the soil which is not covered with a film — 59,7 and 48,2% respectively. Death of all eggs of helminths in firm fraction of liquid manure of cattle this drug causes at introduction it in a dose 10 g/kg, in pork manure — 20 g/kg. At addition in excrements of the ammonium hydroxide containing up to 2,5% of ammonia in a day perishes 32, and in 20 days of 100% of eggs of helminths. Ovitsidny activity of ammonium hydroxide is fullestly shown at t ° 18 — 24 ° and absolutely is absent at t ° 6 — 4 ° below.
During the work with O., especially gaseous (anhydrous ammonia, carbon sulfur, etc.), it is necessary to use individual protection equipment (overalls, respirators, safety spectacles, rubber gloves etc.).
Death of eggs of insects is caused by many drugs. So, acetophos and its analog methylacetophos in the form of water solutions, ointment and shampoo, the water emulsion dikrezit, water and soap suspension of benzyl benzoate and nek-ry ethers acrylic to - you perniciously affect eggs of louses. Eggs of flies, mosquitoes, louses, bugs perish under the influence of karbofos. Toxic action render on eggs of flies and bugs also hlorofos, metilnitrofos, a trikhlor-metaphos-3.
Methyl bromide in gaseous state in a dose of 340 g on 1 m3 on exposure causes 3 hours death of 100% of eggs of louses, bugs, red cockroaches.
V. D. Larionova, N. A. Romanenko.