From Big Medical Encyclopedia

CRESOLS (synonym: oksitoluola, methylphenols) — organic compounds of an aromatic series, derivatives of benzene, have toxic properties; are used as desinfectants, and also in production of herbicides, antioxidants, by production of plastic, in the perfumery industry, at production of dyes.

As all direplaced benzene, cresol has orto-, couple - and metaisomers.

To. have subacidic properties and with alkalis form salts (cresylates), well water soluble. To. easily react on hydroxylic group (e.g., reactions of education simple and esters), and also in reaction of electrophilic and nucleophilic substitution on an aromatic ring (e.g., reactions of halogenation, a carboxylation, etc.). By the most effective method of the analysis of mix K. is gas-liquid chromatography (see). To. for the technical purposes receive from oil and coal tar distillation and extraction by alkalis in the form of mix from three isomers, so-called. Tricresolum (see). au-Izomer (the most flying of all) it is possible to allocate in pure form from trikrezolny fraction with method of differential distillation, and division of m and n-isomers make razgonky their derivatives. Pure isomers K. receive in also synthetic way. To. are used in production herbicides (see) and cresol - aldehydic plastic. To. are a part of antioxidant of an ionol (see. Antioxidants ).

To., like phenol, possess the sharp irritating and cauterizing action on skin. Depending on the place and duration of influence To. can cause burning, erubescence, an itch, bulging, eczemas etc. To. cause also irritation of mucous membranes and a conjunctiva. Warty growths on skin of a scrotum at the people working with To are described. At intake of cresylic acid, lysol (see) and other substances containing To., there comes poisoning.

Acute poisoning with cresol has the following clinical symptoms: pains in a gullet and a stomach, vomiting (emetic masses with a characteristic smell of the crude phenol). Dizziness, loss of consciousness, loss of reflexes, spasms. Pallor of integuments.' Pupils are expanded. Breath is slowed down, a fluid lungs. Wet rattles. Pulse is speeded up, weak filling, body temperature goes down, coma quite often develops. Urine has dark and olive color and may contain erythrocytes. Death comes at the phenomena of paralysis of breath.

Hron, poisonings To. are shown by headaches, an eructation, vomiting, increase in the ABP, increase in allocation phenols (see) with urine (to 67,7 mg/l instead of 12,0 mg/l is normal). After improvement a gigabyte. conditions in workrooms all patol, displays of poisoning To. disappear.

Liquid To. are soaked up through skin; in blood, in urine and in bodies are found in a free and connected state with sulfuric and glucuronic to-tami. Allocation To. comes from an organism quickly.

Maximum allowable concentration for Tricresolum — 0,5 mg/m 3 , for Tricresolum supporting 30% of au isomer — 0,1 mg/m 3 .

At hit in reservoirs To., actively being oxidized, worsen the oxygen mode therefore the drain waters containing more than 0,001 mg/l To., shall be cleared.

Measures of the prevention

in the presence of vapors K. in air of workrooms it is necessary to work in the industrial filtering gas mask of brand A, in the presence of aerosols — in the same gas mask with the filter or in a respirator. Protection of eyes and skin (overalls, rubber gloves and aprons), and also disguise before going away from work and frequent cleaning of overalls is obligatory. Mechanization of those tekhnol is necessary. processes at which hit is possible To. on skin.

First aid

At hit To. on clothes its immediate change. Rubdown of the wounded places of 10 — 40% ethanol or vegetable oil. Warm shower. According to indications rest, warming, caffeine, Cordiaminum, intravenously glucose of 40% solution on fiziol, solution, 30% solution of sodium thiosulphate (8 — 10 ml). If necessary calling of vomiting, a gastric lavage warm water with active coal or a suspension of magnesia usta before disappearance of a smell of phenol. Later castor oil, ovalbumin, mucous broths, pieces of pure ice.

Definition To. in air it is based on formation of the painted nitro compound at interaction To. with nitric to - that in the sulfate environment at 80 — 100 °. Test-sensitivity — 4 mkg in the kolorimetriruyemy volume of solution.

Qualitative tests for identification To. in solutions: 2 ml of a chlorine water and 5 — 6 drops of ammonia with au cresol give the yellow-brown coloring passing into greenish; with m cresol — the green coloring passing in dark yellow; with n-cresol — the dark yellow coloring passing in orange or red.

Definition To. in a human body. N-cresol is emitted from urine with wet distillation, nitrated and carry out a polarographic analysis (see. Polyarografiya ).

Cresols in the medicolegal relation

At court. - a medical research of a corpse of the person who died as a result of poisoning To., observe sharp irritation of a mucous membrane of a gullet and stomach, existence on their surfaces of the condensed sites, dot hemorrhages on internals and in a brain, a fluid lungs, fatty regeneration of parenchymatous bodies. The smell of the crude phenol can be felt.

Judicial and chemical definition. From internals of a corpse To. isolate wet distillation in the subacidic environment.

Reactions of detection To. in distillate: formation of a white deposit at action of a bromine water; emergence of blue-violet coloring at interaction of the distillate containing To., with freshly cooked solution of ferric chloride.

During the definition To. in blood after wet distillation in the presence of wine to - you colored compound K. with 2,6-дибромхинон - 4-chlorimidoum extract isoamyl alcohol and fotometrirut.

Table. Physical properties of cresols

Bibliography: Harlampovich G. D. and Churkin Yu. V. Phenols, M., 1974; Sh in and y to about in and M. D. Toxicological chemistry, M., 1975, bibliogr.; W e n g-le B. H e 1 1 s t r o m K. A gas chromatographic technique for the analysis of volatile phenols in serum, Scand. J. clin. Lab. Invest., v. 28, p. 477, 1971, bibliogr.

H. V. Prokazova; A. F. Rubtsov (court. medical).