NITRILES (cyanides) — organic derivatives of cyanic acid. N treat highly toxic and dangerous connections. The lowest members of a number of nitriles — liquids, the highest — crystal substances. Temperature of boiling of nitriles increases in a homologous series from 81,5 ° (CH 3 CN) to 224 ° (C8H17CN). Other members of a row boil only with the lowered atmospheric pressure. N badly of a rastvorima in water, are saponified by alkalis and to-tami with formation of ammonia and carboxylic to - t, dissolved in benzene and other organic solvents. Receive N. at interaction of potassium cyanide with alkyl halides.
N are widely applied in production of insecticides (galoido-nitriles), chemical fibers, plastic, polyfoams, spongy sealants, etc.
According to one researchers, N.'s toxicity is caused by release of an ion of cyan in an organism, and according to others, N.'s toxicity is connected with action of the whole molecule since in urine H. find in not changed look. N.'s action on an organism is similar to effect of inorganic cyanides.
Get to N.'s organism through respiratory organs and skin. For air of working zone maximum allowable concentration of acrylonitrile — 0,5 mg/mg, acetone cyanohydrin — 0,9 mg/m 3 , an acetonitrile — 10 mg/m 3 .
At acute poisoning of N. the victim has a feeling of bitter, unpleasant, metal taste, burning sensation in oral cavities, pain and constraint in a breast. Breath is speeded up. At influence of big concentration of N. almost instantly there comes the loss of consciousness, there is sharp short wind, expansion of pupils, an exophthalmos, spasms. In these cases there can come death owing to paralysis of a respiratory center.
The clinical symptomatology hron, N.'s poisonings is quite changeable and various. Patients complain of severe headaches, sleeplessness, nausea, pressure sense to breasts and in a stomach, burning at an urination. A hyperexcitability, irritation of conjunctivas, a coated tongue, increase in a liver and easy icteric coloring of scleras are noted.
First aid and treatment at N.'s poisoning: the victim needs to be taken out on fresh air, to quickly take off from it clothes, to allow to inhale amyle nitrite (see). Intravenously enter an antidote according to the accepted scheme. During the falling of cordial activity enter adrenaline, caffeine, ephedrine. It is necessary to alternate inhalation of Carbogenum each 15 — 20 min. to inhalation of oxygen. After the victim recovers consciousness also its breath will be recovered, he is urgently hospitalized.
All works with N. shall be carried out in the tight equipment, whenever possible separately from other processes, using distance steering, local and all-exchange ventilation (see). It is necessary to exclude N.'s hit on skin, to provide after work washing in soul, to carry out careful cleaning of overalls. Apply the filtering gas mask of brands M, A, B to protection of a respiratory organs, at high concentration — hose or isolating gas mask (see).
Bibliography: Harmful substances in the industry, under the editorship of N. V. Lazarev and E. N. Levina, t. 2, page 91, L., 1976; Industrial hygiene and toxicology, ed. by F. A. Patty, v. 2, p. 1992, N. Y. — L., 1965.
E. H. Marchenko.