chemical substances having antimicrobial effect. Depending on the concentration, duration of exposure, microbial sensitivity to the drug, and so forth, any antiseptic may in some circumstances cause the destruction of microbes, which is known as a bactericidal effect, and in other circumstances inhibit their growth—that is, have a bacteriostatic effect. The bactericidal activity of antiseptics depends on their chemical structure, temperature, and pH factor and the presence of protein substances which serve as a nutrient medium for bacteria. The bactericidal activity of most antiseptics drops sharply if proteins are present.

The effect of an antiseptic on microorganisms depends essentially upon interaction of the antiseptic with proteins, with the enzyme system, and with other systems of the cell of the microbe, all of which brings about its eventual destruction. Antiseptics began to be used long before the role of microorganisms in the development of infection was understood. Thus, as far back as the 1830’s the Russian pharmacologist A. P. Neliubin recommended chloride of lime (bleaching powder) for disinfecting various objects; and in the 1840’s the Hungarian physician I. P. Semmelweis proposed that it be used to disinfect the hands of personnel before examination of parturient women. In the 1860’s the English physician J. Lister initiated antisepsis when he introduced phenol (carbolic acid) as an antiseptic in surgical practice. Later, L. Pasteur, E. Metchnikoff, R. Koch, and others established the role of microorganisms in pathology and scientifically substantiated the use of antiseptics.

In medicine, antiseptics are used for disinfection of rooms (carbolic acid, cresol, Lysol, thymol, Formalin, propiolac-tone, mercuric chloride, calcium hypochlorite, chloramines, and others) and for the treatment of the surgeon’s hands prior to surgery (green soap, “diocidum,” ammonia water, and alcohol solution of iodine). In treating infectious or infesta-tious diseases, the method of applying a given antiseptic depends on the type of disease, the kind of operation, the localization of the pathologic process, the possibility of draining the wound, and the type of microbes. Antiseptic ointments may be applied to the skin and mucous membranes, wounds may be washed with antiseptic solutions, tampons and moisture-drying dressings may be impregnated with antiseptics, wounds and cavities may be irrigated with antiseptics, wounds may be sprinkled with antiseptics in powder form, and so forth. Some antiseptics are used internally; they are introduced intramuscularly, intravenously, or intra-arterially. Methylene blue, hexamethylenetetramine, and other antiseptics are used in infestations and in various kinds of dermatosis. Aqueous and alcohol solutions of resorcin, pyrogallol, brilliant green, mercury bichloride, and Ichthyol are among those used in skin diseases. Furacilin, ethacridine, “flavocridine,” hydrochloride, boric acid, hydrogen peroxide, Protargol, Collargol, silver nitrate, and pantocid are used for washing suppurative cavities and as rinses for treating suppurative wounds. Propiolactone is used to sterilize many biological fluids and preparations (blood, vaccines, enzymes, nutrient media, and transplants). Soda, furacilin, and potassium permanganate are among those used for irrigation, inhalation, and so forth.

In the food industry antiseptics are used to preserve food products. The simplest antiseptic for this purpose is acetic acid; sometimes benzoic and salicylic acids are also used.

Antiseptics are widely used to protect various nonmetallic materials (wood and wood products, textile products, leather, plastics, etc.) from destruction by microorganisms. The antiseptics used for this purpose must be stable, must not absorb moisture, and must not wash out with water. They must also be relatively safe for humans and animals, must not generate poisonous substances or unpleasant odors when used, and also must not hamper subsequent processing or coloring of the material. Antiseptic treatment of building materials and products is done by soakingin tubs, by applying pressure, and by other methods. The following are used to protect lumber, fiberboard, splint board, peat and reed board, laminated wood plastic, and other products from destruction by microorganisms: water soluble antiseptics (sodium fluoride, sodium fluosilicate, blue copperas, sodium dinitrophenolate, and others); non-water soluble, or oily, antiseptics (creosote and anthracene oils, railroad tie-impregnating shale oil, and others); and antiseptic pastes (bituminous and others). Sometimes compounds of arsenic, copper, and chrome, such as arsenates or arsenites of copper or zinc, are also used as antiseptics.

Chlorine derivatives of dioxydiphenylmethane, zinc salicylanilide, salicylanilide and the products of its chlorina-tion, 8-hydroxyquinoline and copper-8-quinolinolate, chlorine derivatives of phenol, hydroxydiphenyl, and others are used to protect textiles, plastics, and other materials. Organic compounds of mercury (ethylmercuric phosphate, phenylmercuric acetate, phenylmercuric oleate, and others), bromofluorodinitrobenzol, and other compounds are used as antiseptics.

Antiseptics used in the war against harmful microorganisms in agriculture include fumigants and fungicides.