From Big Medical Encyclopedia

EFYRY — the general name of two types of organic oxychemicals — simple and esters. Many biologically important connections and substances finding various practical application including in medicine belong to ethers. Nek-ry simple and difficult E. on the productions connected with their receiving and use can represent, themselves professional harm. Both types of ethers are eurysynusic in a plant and animal life.

The general formula of ethers R — About — R, where R — the hydrocarbon or replaced radical. AA. with identical hydrocarbon radicals call symmetric, and AA. with different hydrocarbon radicals — mixed. Names simple E. make from names of hydrocarbon radicals (in alphabetical order) with addition of the word «ether» or from the name of the RO group used as a prefix, and the name of RH hydrocarbon; also trivial, traditionally developed names are applied. So, C2H5OC2H5 is called diethyl ether, or ethoxyethane, CH3OC3H7 — methyl-propyl ether, or metoksi-propane, SBN5OSN3 — metilfe-nilovy ether, or metoksiben-zoly (anisole). Exist also cyclic simple E. (ethylene oxide, tetrahydrofuran, dioxane, etc.). From simple E. the diethyl ether used for an anesthesia and also for external use, preparation

of tinctures and extracts is most known (see. Ethyl ether). Derivatives simple E. many alkaloids (see), essential oils (see), a lignin and other substances, and also nek-ry pharmaceuticals, napr, acetphenetidiene are (see). Reaction of education simple and difficult E. widely apply to protection of hydroxylic and carboxyl groups in chemistry of multifunctional connections (peptides, carbohydrates, nucleotides, etc.). In industrial organic synthesis ethylene oxide is of great importance, technically important polyethyleneglycols are also ethers. Nek-ry cyclic E. (crown-ethers) found application as reagents in organic chemistry (see).

Acyclic simple E. — these are liquids with a characteristic («radio») smell, temperature of boiling to-rykh much lower than temperature of boiling isomeric to them alcohols (see). Alkilarilovye E. are the high-boiling liquids or solid matters. Simple E., except for CH3OCH3 dimethyl ether, badly rastvorima in water and it is easy in organic solvents (see). Diethyl ether, ethylene glycol ethers, tetrahydrofuran and dioxane are widely used as solvents.

The lowest symmetric E. receive dehydration of alcohols under the influence of sulfuric to - you or other

catalysts: 2R —>

OH^^ R — About — R + H20. By the general method of receiving mixed E. alkylation of alcoholates or phenolates is: CH3ONa + C0H5I -»

— CH3OC2H5 + Nal; CeH5ONa + + (CH30)2S02 C6H5OCH3 +

- j-CH30S03Na; nek-ry mixed E. receive accession of alcohols to alkenes: CH3OH + CH2 =

=> C(CH3)2-CH30C(CH3)3. Bro -

mistovodorodny or monohydroiodide to - that dialkyl and alkilarilovy E. are split on alkyl halide and alcohol (phenol). This reaction is used for quantitative definition of alkoxy-groups (Tseyzel's method).

Simple E. (except purely aromatic) are mild bases thanks to existence of nepode-lenny couple of electrons at oxygen atom, and their chemical properties are defined by hl. obr. reactions with to-tami and similar reagents. So, simple E. are dissolved in strong to-takh with formation of salts of oxonium: R — About — R+HC1 ^ [R — IT is R] + C1" and form similar complexes with so-called Lewis acids, e.g. (C2H5)20*BF3. In usual conditions simple E. are steady against action of the bases and alkaline threw -

fishing (sodium is applied to drying simple E.). Oxygen of air simple E., especially isopropyl ether and tetrahydrofuran, gradually are oxidized to explosive peroxides (peroxides). Before use simple E. it is necessary to check surely for availability of peroxides and if necessary to delete them, napr, with processing by salts of bivalent iron.

Difficult E. represent derivatives of organic or inorganic oxygen acids, in to-rykh hydrogen of acid group it is replaced on an organic hydrocarbon radical (alkyl, aryl, etc.). In difficult E. carboxylic to - t with the general formula K — With — OR', where I!


R and R' — hydrocarbon radicals, the rest carboxylic to - you are R — With —



(acyl) it is connected with the rest of alcohol or phenol — OR' therefore difficult E. consider also as acylic derivatives of alcohols or phenols. Polybasic to - you can give products of incomplete substitution — acid E. Names difficult E. form of names of anion of acid and the hydrocarbon radical of alcohol or phenol, e.g. CH3COOC2H5 — ethyl acetate (ethyl ether acetic to - you), C6H5COO — CH3 — methyl benzoate (methyl ether of the benzoic to - you), C2H50803H — ethylhydrosulphate (ether ethyl ether a chamois to - you).

Difficult E. many vegetable products — components of essential oils, pitches, wax (see), alkaloids, etc. are. Ethers of glycerin (see) and fatty acids (see) make a basis of fats (see), the major physiologically active agents are nek-ry ethers acetic to - you, napr, acetylcholine (see). Ethers of phosphoric acids (see) are a part of nucleic acids (see), lipids (see) and other biologically active compounds. Row difficult E. carboxylic to - t (tg-aminobenzoic, salicylic, etc.) and mineral to - the t (nitrogenous, nitric, phosphoric) is pharmaceuticals. Difficult E. apply as solvents, semi-products of organic synthesis, fragrant substances, in production of polymers, in the food industry and in other industries.

AA. the lower and average homologues acyclic and aromatic carboxylic to - t and the lower alcohol represent liquids often with a pleasant (fruit) smell, almost water soluble and well dissolved in organic solvents. Ethers of the highest to - t are solid matters. AA. mineral to - t and the lower alcohol — the liquids, thermally less steady, than ethers of carboxylic acids; nitric acid ethers are explosive.

By the main methods of receiving difficult E. serve reversible interaction carboxylic and nek-ry mineral to - t with alcohols — etherification (see) — usually in the presence of acid catalysts (a chamois to - you, etc.), and also acylation of alcohols and phenols anhydrides or acid chlorides to - t in the presence of the bases (alkalis, pi-


of Ruthin, etc.): RCOOH +

ROH^± RC00R' + H20; RCOCl + R'OH — ^ RCOOR' + C5H5N.HC1. Both of these reactions often apply to identification &arbonovsh1: to - t, spir

t and phenols. For difficult E. reactions of splitting, first of all hydrolysis or saponification (see) — reaction are characteristic, the return etherifications, edges is catalyzed to-tami either the bases or enzymes by esterases (see). Difficult E. interact with such nucleophilic reagents as ammonia, amines, a hydrazine, hydroxylamine. Reactions of receiving various derivative carboxylic acids, including pharmaceuticals belong to such reactions: RCOOR' + + NH2X-^RCONHX + R'OH where X can be hydrogen, alkyl, an amino group or hydroxylic group. For the synthetic purposes various condensations difficult E are used. and others specific for such E. reactions. Ethers a chamois to - you and aromatic sulfonic acids are the good alkylating means.

For qualitative and quantitative test simple and difficult E. use also Ishchinfrakras-nuyu) - spectroscopy and nuclear magnetic resonance (nuclear magnetic resonance) - spectroscopy (see Spectroscopy), mass spektro-metriyu (see) and various chemical methods.

Ethers as professional harm. AA. can be allocated in air of workrooms in the course of receiving these chemical connections and at their use as anesthetics, pesticides, solvents, plasticizers, heat carriers, explosive substances and DR-

Under production conditions E. can come to a human body through airways and skin. Majority E. it is substantially allocated from an organism in not changed view with expired air, partially with urine. AA. possess preferential narcotic action, many of them irritate mucous membranes of eyes and upper airways, skin, nek-ry of E., generally simple, possess hepatotoxic and nephrotoxic action.

The most characteristic representative simple E., possessing narcotic action, diethyl ether (ethyl ether) used as anesthetic or a component of narcotic mixes is. At hron. intoxications diethyl ether note * loss of appetite, nausea, occasionally vomiting, persistent locks, apathy, pallor of integuments, headaches, dizziness, intolerance of alcohol. At the anesthesiologists who are constantly working with diethyl ether often reveal vegetative lability, increase in tendon jerks, cardiovascular frustration, changes in blood.

At acute poisoning with diethyl ether it is characteristic following wedge, a picture: in the beginning excitement, gaiety or pugnacity, then drowsiness, confusion and loss of consciousness. At slight intoxication diethyl ether note a headache, nausea, lack of appetite, a back pain, the general weakness. Bronchitis, pneumonia, a toxic nephropathy, a hepatopathy, encephalopathy can be complications of acute poisoning with diethyl ether.

Maximum allowable concentration of diethyl ether is equal in air of a working zone to 300 mg/m3.

Fluorinated and bromsoderzhashchy simple E. also chlorine-containing ethers — hl possess preferential narcotic action, and. obr. the irritating and all-toxic action. On ability to cause dystrophic changes in parenchymatous bodies these E. remind galogenoproizvodny hydrocarbons (see. The brominated hydrocarbons, Chlorinated


Couples chlordimethyl and dichlorine - methyl ethers at short-term inhalation cause sharp irritation of a mucous membrane of respiratory tracts, sometimes from the death. On force of irritant action these E. equate to chemical warfare agents (see). Result of slight poisonings with couples such E. there can be a development of bronchitis, emphysema of lungs, bronchial asthma, an abnormal liver function, damage of skin (dermatitis), changes of blood (a thrombocytosis, basophilic stippling of erythrocytes). There are data on cancerogenic effect of chlordimethyl and dichlordimethyl ethers.

1,1 Difluorine - 2,2-dy loretilmet lo-vy ether (Inhalanum) possess the narcotic action surpassing narcotic effect of diethyl ether by 6 times. Irritant action this E. does not possess. Inhalanum constitutes potential danger to personnel of operating rooms especially as it is well absorbed by clothes, skin, the surface of operational devices. Steam inhalation of Inhalanum especially often leads to damage of a liver and kidneys. Fatal cases after repeated use of it E are described. for an anesthesia.

Maximum allowable concentration of 1,1-difluorine-2,2-dichloroethyl-methyl ether is equal in air of a working zone to 200 mg/m3.

Simple E. diatomic and triatomic alcohol possess narcotic and irritant action, in high concentration they can cause injury of kidneys, disturbances of functions of a nervous system. These E. are dangerous at receipt through skin. The most toxic connection among them is methyl ether of ethylene glycol (methyl cellosolve).

Simple E. phenols (guaiacol, di Nile, etc.) can cause irritation of mucous membranes of eyes, upper airways, skin, and also a headache, dizziness, a memory impairment. At the termination of contact with them note bystry recovery of health.

Nature of toxic action «false E. on a human body and animals depends not only on the chemical nature of these connections, but also on the chemical nature of their metabolites which are formed in an organism, especially from acid — a product of hydrolytic decomposition difficult E.

Slozhnye E. halogenated to - t (chlorant, chlorocarbonic, galogenuksusny to - t) irritate mucous membranes of respiratory tracts. Nek-rye from these E. possess strong all-toxic action due to formation of highly toxic metabolites; e.g., a metabolite of a trikhlormetilkhlorformiat is phosgene. Slight poisoning trikhlormetilkhlorformiaty is shown only by irritation of a conjunctiva and a mucous membrane of upper respiratory tracts. At moderately severe poisoning lungs up to development of a tracheobronchitis and pneumonia are involved in process. At a serious poisoning after the period of imaginary wellbeing lasting from 1 to 24 hours after contact with trikhlormetilkhlorformiaty against the background of irritation of mucous membranes of eyes and upper respiratory tracts there is sharp asthma, cyanosis, cough with plentiful department of a phlegm, the fluid lungs develops. Body temperature raises sharply, noted a pachemia, the oliguria, emergence of protein in urine, a frequent complication is bronchial pneumonia. A critical period of intoxication trikhlormetilkhlorformiaty are the first two days after hit of poison in an organism.


Difficult E. fat to - t with nonlimiting alcohols possess the strong irritant action surpassing action E. fat to - t with limit alcohols. So, vinyl acetate shows stronger irritant action, than ethyl acetate. At hron. poisoning such E. complaints to a headache, dizziness, increased fatigue, irritability, a sleep disorder are characteristic. At over 10 years working with these substances at length of service with professional harm note the expressed changes from a nervous system, development of an astenovegetativny syndrome (see. Asthenic syndrome), polyneurites (see the Polyneuritis). Acute poisoning E. fat to - the t with nonlimiting alcohols is shown by sharp irritation of a conjunctiva and a mucous membrane of upper respiratory tracts.

Maximum allowable concentration of vinyl acetate in air of a working zone makes 10 mg! m3, and ethyl acetate — 200 mg/m3.

Possess stronger irritant action difficult E. galogenozameshchenny alcohols (methyl-bromatsetat, etilbromatsetat, ethyl-iodacetate, etc.), capable at acute poisoning to cause a fluid lungs, multiple hemorrhages in them, damages of skin.

Difficult E. nonlimiting to - t possess preferential narcotic and all-toxic action (e.g., methylmethacrylate); nek-ry E. such to - the t (methyl acrylate and ethyl acrylate) show also irritant action.

Hron. poisoning with methylmethacrylate (the most characteristic representative E. nonlimiting to - t) it is shown by a symptom complex of defeat of a nervous system. Functional vegetovascular frustration are characteristic of an early stage of poisoning; in more hard cases disturbances of painful sensitivity in distal departments of extremities, decrease in excitability of a vestibular mechanism, reduction of activity of bark of adrenal glands, disturbance of vodnoelektrolitny exchange, change of holinesterazny activity and morfol are possible. composition of blood. At women frustration of a menstrual cycle and genital function are possible.

Acute poisoning with methylmethacrylate is shown by weakness, nausea, vomiting, a headache, dizziness, feeling of constraint in a breast, the loss of consciousness with short-term spasms of epileptiform character is possible. Resistant effects of acute poisoning with methylmethacrylate are noted.

Maximum allowable concentration of methylmethacrylate is equal in air of a working zone to 10 mg/m3.

Difficult E. phthalic to - you (dibutyl phthalate, dioctyl phthalate, etc.) possess preferential neurotoxic action and are capable to cause not only functional, but also organic changes in the central and peripheral nervous system. They can have the hepatotoxic and weak sensibilizing effect. These E. have moderately expressed irritating properties. At nek-ry workers note allergic rhinitises, dermatitis. AA. phthalic to - you acute poisonings are not caused, but are dangerous at hron. impact on an organism.

In development hron. intoxications E. phthalic to - you conditionally allocate three stages: subclinical (pre-pathological), initial clinical and a stage of the expressed disturbances. Characteristic manifestation of the first stage is decrease in skin sensitivity (especially painful), is preferential in distal departments of extremities. The initial clinical stage is characterized by emergence of pain, feeling of numbnessI and weaknesses in hands and legs, dysfunction of analyzers, a tone of vessels. In process of progressing of process in the expressed cases of intoxication there can be a weakness, spasms and a number of the signs characterizing a syndrome of a toxic vegetative polyneuritis. The expressed disturbances at intoxication E. phthalic to - you are characterized a wedge, signs of a polyradiculoneuritis with proteinaceous and cellular dissociation in cerebrospinal liquid and involvement in process of c. N of page. The frequent headache, attacks of the general weakness, unsteadiness of gait, faints, vegetovascular paroxysms with trunk and vestibular disturbances and falling of the ABP are possible. Progressing of a disease can be promoted a peptic ulcer of a stomach and duodenum and others patol. states.

Maximum allowable concentration of dibutyl phthalate is equal in air of a working zone to 0,5 mg/m3.

The dimethyl terephthalate (dimethyl ether terephthalic to - you) used in production of synfil of lavsan at continuous impact on an organism can cause at working the asthenic reactions proceeding against the background of vegeto-vascular dystonia (see Dystonia vascular), disturbances from outside went. - kish. path, heartache, skin itch. In blood note moderate anemia, a reticulocytosis, an unsharp leukopenia with a neutropenia, a lymphocytosis, change of a ratio of protein fractions.

Maximum allowable concentration of dimethyl terephthalate is equal in air of a working zone to 0,1 mg/m3.

Difficult E. hydroxyacids (e.g., butyl-2,4-dikh lorfenoksilatsetat), applied generally as herbicides and growth-promoting factors of plants (in small doses), are characterized by moderate toxicity. These connections have cumulative properties. At acute and repeated poisonings note toxic defeat central and the autonomic nervous system as an asthenic syndrome, a hypotensive syndrome, Qatar of upper respiratory tracts, allergic disorders, disturbances of sense of smell and flavoring sensitivity. The moderate hepatomegalia, a functional gastric disturbance, dermatitis are possible.

Maximum allowable concentration butyl-2,4-dikhlorfeno ksiatse-

the Tat is equal in air of a working zone to 0,5 mg/m3.

The most toxic are ethers of phosphoric, thiophosphoric, tsianfosforny, dithiophosphoric, pyrophosphoric acids (see. Organophosphorous connections), ethers nitrogenous and nitric to - t are less toxic. Organophosphorous connections (FOS) are toxic for the person in different degree. One of them are strong toxic agents (methylmercaptophos, a metaphos, phosphamide, phthalophos, etc.), others (avenine, demufos, bromophos, a gardona, etc.) malotoksichna. Under production conditions poisoning of FOS is possible as a result of inhalation of their vapors, hit of toxic compounds on skin or clothes, swallowings FOS with water and food.

The mechanism of toxic action of the majority of poisonous FOS is based on inhibition of a number of enzymes, in particular cholinesterases (see), to-rye lose ability to react with acetylcholine (see). As a result of suppression of activity of cholinesterase in blood and fabrics not turned acetylcholine collects.

Symptoms of poisoning of FOS divide as follows: 1) muskarino-like (see Muscarine) — nausea, vomiting, spasms in a stomach, hypersalivation, a diarrhea, tenesmus, feeling of constraint in breasts, strengthening of bronchial secretion, a bronchospasm, bradycardia, a miosis, the strengthened sweating; 2) nicotinosimilar (see Nicotine) — twitchings of eye muscles, language, and then and other face muscles and a neck, a nystagmus, fibrillar twitchings of muscles of all body and 3) central (atropinorezistentny) — disturbance of mental Activity, change of the speech, an ataxy, a disorientation in space, a tremor, clonic and tonic spasms, oppression and paralysis of the centers of a myelencephalon.

Klien, a picture of poisoning with various FOS is generally similar. Distinctions consist preferential in expressiveness of symptoms of excitement of the central or peripheral cholinereactive systems, in dominance of muskarinopodobny or nicotinosimilar symptoms and in the speed of development of toxic process.

At hron. poisoning of FOS note a headache, dizziness, heavy feeling in the head, a memory impairment, fatigue, a sleep disorder, reduction of appetite, a disorientation in space. The nystagmus, decrease in lid reflexes (a spasm of accommodation), a tremor of fingers of hands, a smoothness of a nasolabial fold are objectively characteristic. Also changes in blood, selective and permanent defeats of a nervous system in the form of paresis and sluggish paralyzes of preferential lower extremities are possible. Toxic action of a number of FOS is established at hron. poisoning with these connections on cardiovascular system and secretory bodies, and also their bronkhospastichesky action.

The picture of acute poisoning of FOS substantially depends on ways of their receipt to an organism and on amount of the poison which got to an organism. The first symptoms of inhalation poisoning are the miosis, visual disturbances, difficulty of breath, and also symptoms of defeat of the central and peripheral nervous system. At hit of poisons on skin development of muscular fibrillations in the place of penetration of toxic can be the first symptom of poisoning; in this case manifestation of symptoms of intoxication is dragged more out in time, symptoms of excitement of the central holinoreaktivny systems sometimes are more weakly expressed. At receipt of FOS through went. - kish. a path at first usually there are nausea, vomiting, enterospasms, a diarrhea, tenesmus, and other symptoms of resorptive action of organophosphorous connections appear then.

In more detail about poisoning of FOS — see articles Neuroparalytic toxic agents, Pesticides, Organophosphorous connections, Phosphorus, Chemical weapon.

Ethers nitrogenous (ethyl nitrite, bu-tilnitrit, etc.) and nitric to - t (nitroglycerine, dinitroglycol, etc.) preferential cause relaxation of smooth muscles, especially unstriated muscles of small blood vessels (see Nitrogen, Nitrites).

At hron. poisoning with these E. note the pulsing headache, heartbeat, a hyperemia of the person, hypotonia; the ulceration of integuments, dermatitis (see), eczema are possible (see).

At acute poisoning with ethers nitrogenous and nitric to - t are possible a headache, a hyperemia of the person, dizziness; with increase in severity of acute poisoning there come faints, nausea, vomiting, gripes, a photophobia, a sonitus, an asthma, delay of pulse, a cold snap of extremities develop.

First aid and emergency treatment at poisoning with ethers. At acute inhalation poisoning E. it is necessary to remove immediately the toxic connection which was injured from an area of coverage, to quickly take off the clothes and footwear, heat which became wet in toxic to cover and take out the victim on fresh air or to well aired room. Inhalation of the moistened oxygen, alkaline oil inhalations are shown, at persistent cough — dionine (ethyl morphine a hydrochloride), codeine; intravenously enter 20 — 30 ml of 40% of solution of glucose from 5 ml of 5% of solution ascorbic to - you; subcutaneously — cardiacs: Kam

odds (20% solution), caffeine-sodium benzoate (10% solution), Cordiaminum on 1 — 2 ml. If necessary it is possible to give sedatives, strong tea. For prevention of pneumonia enter antibiotics. At respiratory depression inhalation of Carbogenum several times 5 — 10 min. is recommended; according to indications — an artificial respiration, a cut it is necessary to carry out carefully taking into account a possible toxic fluid lungs (see).

At hit toxic E. on skin it is necessary to wash out it water with soap, to neutralize toxic agent of 4% solution of hydrosodium carbonate or to process the surface of skin of 5 — 10% solution of ammonia, 2 — 5% solution of chloroamine B. At acute dermatitis apply indifferent pastes or ointments, at burns — Unguentum Furacilini, a sintomitsi-new emulsion.

At hit toxic E., especially FOS, in eyes it is necessary to wash out immediately eyes a pure stream with the subsequent instillation of 30% of solution of Sulfacylum-natrium and 1% of solution of novocaine. At accidental intake of poison in went. - kish. a path it is necessary to cause as soon as possible vomiting, to make a gastric lavage via the probe of 2% solution of hydrosodium carbonate (to 10 l) and to allow to drink

small pounded active coal (2 — 3 table, l.), to cause repeated vomiting, and in 5 — 10 min. to give salt laxative; intravenously plentiful introduction (to 2 l kapelno) 5% of solution of glucose from 500 mg ascorbic to - you and isotonic solution of sodium of chloride (to 2 l a day), subcutaneously 5 — 10 PIECES of insulin; diuretics.

At the first symptoms of poisoning it is necessary to apply cholinolytics (atropine) at once. At slight intoxication hypodermic or intramuscular introduction of 1 ml of 0,1% of solution of atropine is shown, at poisonings of average or heavy degree enter 3 — 5 ml of 0,1% of solution of atropine intramusculary or intravenously. Good effect note at hypodermic introduction 1 ml of 15% of solution of a dipiroksim (in hard cases to 3 — 4 ml). At a serious poisoning intravenous administration of 5% of solution of ephedrine (0,5 ml), dopamine (4 mg), an early hemodialysis, peritoneal dialysis, hemosorption is shown. At excitement of c. N page and spasms apply hexenal intravenously (5 ml of 10% of solution), Chlorali hydras in an enema (2 g), inside aminazine (0,025 g), intravenously or intramusculary magnesium sulfate (8 — 10 ml of 25% of solution). At disturbances of breath — lobeline or Cytitonum, inhalation of oxygen, if necessary an artificial respiration.

In cases of a serious poisoning E. immediate hospitalization is necessary; it is necessary to transport the victim in a prone position, without stopping supply of oxygen. Treatment acute and hron. poisonings E. etiological, taking into account toxic properties of specific substance, and also pathogenetic and symptomatic.

Examination of working capacity. At slight poisoning E. appoint treatment with release from work or temporary transfer to other work out of contact with profvrednost. At moderately severe poisonings and emergence of permanent disturbances of health or allergic frustration the diseased is discharged of work with harmful substance with the subsequent rational employment (see Examination).

Prevention of poisonings with ethers shall provide use of the progressive production technology (a closed circuit, automation, complex mechanization, distance steering, a continuity and tightness of processes of manufacture, the automatic control of processes and operations and so forth), standardization of the used raw materials, the use of less volatile compounds and other measures for the purpose of reduction of receipt in the environment of toxic gases, exceptions of contact of the person with harmful factors of the production environment and labor process. Special value has use of individual protection equipment of a respiratory organs (see Gas masks, Respirators), an eye (see Points, protective) and skin (see Clothes special, Pastes protective). For protection against vapors and aerosols E. the filtering industrial gas masks of brand A, respirators with antigas cartridges of brand A are applied. Periodic washing and change of overalls are obligatory, its storage in production or premises is forbidden. The rational design of industrial platforms, buildings and rooms, improvement of ventilation (see), control of the content of harmful substances in air of a working zone (see Maximum allowable concentrations), medical examination of the persons having contact with harmful production factors are important (see. Medical examination), observance of measures of personal hygiene, safety regulationss and production sanitation (see). Persons under 18, pregnant women (from the date of establishment of pregnancy) and women during breastfeeding of the child are not allowed to work with ethers.

See also Poisonings, Poisons industrial.

Bibliography: Harmful substances in the industry, under the editorship of N. V. Lazarev and E. N. Levina, t. 1, L., 1976; And d and - a skin I. D. and Filov V. A. Transformations and definition of industrial organic poisons in an organism, JI., 1971; Luzhniki E. A. Clinical toxicology, M., 1982; T e r-

N e y A. L. Modern organic chemistry, the lane with English, t. 1 — 2, M., 1981., See also bibliogr. to St „Poisonings, Poisons industrial.

A. I. Tochilkin (biochemical), E. V. Turbin