METHYL ALCOHOL

From Big Medical Encyclopedia

METHYL ALCOHOL (synonym: methanol, methyl alcohol, carbinol, oxymethane, wood alcohol) — first member of a homologous series of limit monoatomic alcohol; CH 3 OH; strong poison with the expressed cumulative properties, affects preferential nervous and cardiovascular systems. It is used as a fixing agent at histologic researches of blood smears and other drugs as solvent for many dyes applied in microscopy; in kliniko-biochemical laboratories finds broad application as organic solvent. The m of page serves as mother substance in synthesis of many pharmaceuticals (see). In large numbers it is used for production of formalin, receiving various methylating agents, synthesis of fragrant substances (methyl ethers of the benzoic, anthranilic and salicylic to - t). M of page apply as solvent to preparation of polishes and varnishes, as additive to liquid fuels to increase in their octane value and as antifreeze.

For the first time M. page was described by the English scientist R. Boyle in 1661 as «neutral substance» as a part of the liquid received at dry distillation of wood. In 1834 fr. chemists J. Dumas and Peligo (E. M of Peligot) established a formula M. of page — CH 3 OH.

In M.'s nature of page in a small amount meets in plants of a geraklea (Heracleum), in leaves of chestnuts and lindens, in nek-ry essential oils. According to Uestern (O. of Western), blood of healthy people contains from 25 to 245 mkg of % of M. of the village Nek-roye M.'s number of the village is revealed also in urine.

The m of page represents a colorless liquid with the characteristic smell reminding a smell of spirit of wine (ethanol) and burning, off-flavor. Pier. weight (weight) 32,04. Ud. the weight (weight) at 15 ° 0,79609; t ° kip 64,65 °. The m of page in every respect mixes up with water and the majority of organic solvents. Easily ignites and burns with a pale, bluish flame, with air forms explosive mixtures.

Till 20th 20 century products of dry distillation of a tree were the only source of M. of page. However now M. villages in industrial quantities receive by catalytic recovery of carbon monoxide hydrogen: CO + 2H 2 -> CH 3 OH.

All reactions of primary alcohols are characteristic of M. of page. It reacts with alkali metals, forming the corresponding methylates, e.g. 2CH 3 OH + 2K —> 2CH 3 OK + H 2 . At influence of halides of phosphorus or galoidovodorodny to - the t from M. of page are formed methylhalogenides: CH 3 OH +PCl 5 —> CH 3 Cl + HCl + POCl 3 . With a chamois to - that M. the page forms monomethyl sulfate (ether methyl ether a chamois to - you) or methyl-sulphuric to - that: CH 3 OHSO 2 >OH — CH 3 OSO 2 OH + H 2 O. Dimethyl sulfate is formed at M.'s interaction by the village with the smoking chamois to - that. Methylhalogenides, methyl-sulphuric to - that and especially dimethyl sulfate are widely applied in chemistry to carrying out reaction methylations (see).

M.'s transformation by the village in an organism of mammals is carried out by slow oxidation through formation of formaldehyde and ant to - you to carbonic acid and water. The m of page can be neutralized in a liver as a result of formation of glucuronic ethers.

Professional harm. The m of page is strong poison of preferential nervous and cardiovascular action with the expressed cumulative properties; besides, it has a nek-eye narcotic effect, irritates mucous membranes of upper respiratory tracts and eyes. Defeats of an organ of sight up to a total blindness at M.S.'s arrival in an organism through lungs, skin are typical or went. - kish. path.

The first symptoms of intoxication of M. of page are caused by M.'s action by the village; further serious consequences are caused by the combined action of M. of page and formaldehyde.

Maximum allowable concentration of vapors M. of page is equal in air of a working zone to 5 mg/m 3 (with the danger warning of arrival of M. of page through skin).

Poisonings

Acute and hron, M.'s poisonings with page arise at exceeding of maximum allowable concentration of its vapors in air, and also at M.'s hit by the village on the unprotected skin or at strong pollution of overalls and footwear. M.'s reception by the village inside instead of alcohol is especially dangerous: 5 — 10 ml of M. of page can cause a serious poisoning, and 30 ml — to lead to death.

At hron, M.'s poisoning with page oxidation-reduction processes in a brain are broken, changes of vessels of a brain and especially vessels of an organ of sight, leading to changes and partial death of photoreceptor, ganglionic cells appear retinas (see), to growth of a glia, degenerative changes of neurons in the central part visual analyzer (see). At M.'s poisoning with page dystrophic changes in hepatic cells develop that leads to resistant functional inferiority of a liver, not disappearing after a wedge, recovery.

Hron, poisoning with small concentration of M. of page is characterized by dizziness, a headache, sleeplessness, increased fatigue, went. - kish. frustration, deterioration in sight, first of all color. At hron, influence of vapors M. of page in concentration of 50 mg/m3 and above at working at the factory connected with receiving or M.'s use by the village functional changes of an organ of sight are revealed.

Acute poisoning of M. of page is characterized by a condition of easy intoxication, nausea, vomiting, a severe headache, sharp deterioration in sight up to a blindness, during the weighting of a state cyanosis, the complicated breath, expansion of pupils, spasms and death from an apnoea develop. The diagnosis is confirmed by detection in urine ant to - you, and also the analysis of emetic masses and the drunk not enough liquid.

First aid

At M.'s hit by the village in eyes it is necessary to wash out them a strong water jet, at pollution of skin — quickly to wash away from it M. of page water and to replace clothes.

At M.'s reception by the village inside it is necessary to begin immediately a gastric lavage and to continue it within the first 2 hours, it is also necessary to begin fight against acidosis by introduction in 2 — 4 l and intravenously 1 l of 5% of solution of hydrosodium carbonate (baking soda). Intravenously enter 5% solution of alcohol, to-ry, competing with M. page for oxidizing enzymes, education in an organism of toxic metabolites of M. of page detains. According to indications — zamenny hemotransfusion, hemosorption (see. Hemosorption ), inhalation of medical oxygen, cardiacs.

Similar measures are taken at poisoning with the substitutes of spirit of wine containing impurity M. of page (see. Denatured alcohol ).

Measures of the prevention

M.'s Use by the village is allowed only in those productions where it cannot be replaced with less toxic. In the USSR production of polishes, mastics and nitrovarnishes on M. is forbidden to page. The enterprises are obliged to coordinate M.'s introduction by the village to production with bodies a dignity. supervision. Marking of a container for M. pages, rules of its storage and an expense are especially strictly regulated to exclude accidental reception of M. of page inside. The pages working with M. undergo special instructing, are provided with protective gloves, rubber aprons and gas masks of brand «A». The working clothes are washed by each 10 days.

Methyl alcohol in the medicolegal relation

M.'s Poisonings with page quite often happen group; usually victims are insufficiently informed on M.'s virulence of page or neglect it. A lethal dose at intake of 30 — 100 ml.

Tsatologoanatomichesky changes are characteristic of acute death and demonstrate defeat of vascular system (the expressed plethora from a stazama and small multiple hemorrhages in a brain and other internals, hemorrhages in serous and mucous membranes, dark «tar-like» blood in large vessels and sine of a firm meninx, etc.). The symmetric centers of a softening in a brain, in the field of the internal capsule, a striate body, sometimes a cerebellum are observed. M.'s distribution by the village in internals depends on abundance in them of water therefore for a chemical research take blood, urine, cerebrospinal liquid, a kidney, a liver, a brain and a stomach with contents. The m of page is quickly soaked up and slowly is oxidized, in blood its maximum concentration is created in 4 — 16 hours; is longer than all M. the page remains in cerebrospinal liquid — up to 12 days.

The m of page is partially allocated with a mucous membrane of a stomach therefore in rinsing waters and emetic masses it can be found during 2 days. Ant to - that is a poisonous metabolite of M. of page — contains in blood, urine, a liver, kidneys and a brain. With urine it is allocated within 5 — 6 days.

For court. - chemical detection of M. of page use a method of gas-liquid chromatography (see).



Bibliography: Careful R. V. Forensic medical examination of poisonings with technical liquids, page 26, M., 1977; Harmful substances in the industry, under the editorship of N. V. Lazarev and E. N. Levina, t. 1, page 363, L., 1976; Gadaskina I. D. and Filov V. A. Transformations and definition of industrial organic poisons in an organism, page 232, L., 1971; Egorov Yu. L., etc. A condition of an organ of sight of the synthetic fatty acids and alcohols working in production and questions of hygienic rationing of content of alcohols in air, the Gigabyte. work and the prof. having got sick., No. 11, page 33, 1966; Nesmeyanov A. N. of an inesmeyanovn. Beginnings of organic chemistry, book 1, M., 1974; Roberts J. ikaseriy. Bases of an organic hidiya, the lane with English, t. 1, page 405, M., 1978; Rozenbaumn.D. Occupational health during the work with organic solvents, Sverdlovsk, 1946; M about with-s with h 1 i n S. Klinik und Therapie der Vergiftungen, Lpz., 1964.


V. I. Rozengart; Yu. L. Egorov, P. V. Berezhnaya (court.).

Яндекс.Метрика