Aldehydes

Aldehydes - organic compounds with the General formula RC(O)H, where R is a hydrocarbon moiety, CH - carbonyl function group determines their main reactions.
Aldehydes fatty number of gases or volatile liquid, soluble in water, aromatic aldehydes - little volatile and poorly soluble in water. Aldehydes play an important role in biological processes. In particular, aminesformed during the decarboxylation of amino acidsinto aldehydes with subsequent oxidation of fatty acids.
In medical practice are applied directly aldehydes (formaldehyde, paraldehyde is recommended and others)and their derivatives [hexamethylenetetramine (methenamine), chloral hydrate , and others].
The toxic aldehydes. Couples have their sharp irritating effect on the mucous membranes of the eyes and upper respiratory tract, while aldehydes may be narcotic. Of greatest Toxicological significance formaldehyde and acrolein.
Formaldehyde (formic aldehyde) used in the manufacture of synthetic resins, plastics, aniline-dye industry. Under normal conditions - irritating gas with a sharp smell. 40% aqueous solution of formaldehyde - formalin - releases formaldehyde at room temperature. In high concentrations of formaldehyde irritates the mucous membranes of eyes and respiratory tract (acute conjunctivitis, rhinitis, bronchitis), causes Central nervous system (drowsiness, headache, weakness), retina, disrupts the function of the gastrointestinal tract, liver, kidneys. Chronic poisoning observed: diseases of the nervous system (manifested in anxiety, disorders of skin sensitivity, paresis and paralysis), visual disturbances (described cases of vision loss, the development of dermatitis, urticaria, eczema, sometimes bronchial asthma.
Acrolein (acrylic aldehyde, caldigit) - a colourless liquid with a smell of rancid fat. Soluble in organic solvents. Meets anywhere glycerin or fats are heated. Is used in production of plastics, in organic synthesis. Effect on the body is the same as formaldehyde. May develop hypersensitivity. Symptoms of acute poisoning acrolein - pain in the eyes, slezotechenie, swelling of the eyelids, digging in my throat, cough, dizziness, headache, tides blood to the head, nausea, vomiting, blueness of the skin, cardiovascular disorders.
First aid for poisoning aldehydes. Acute poisoning aldehydes, including formaldehyde and acrolein, the victim must bring in the fresh air, to flush mucous membranes 2% alkaline solution. With symptoms of asphyxia - inhalation of oxygen, according to testimony heart funds.
Prevention of occupational poisoning - sealing and mechanization of processes related to the release of aldehydes, effective ventilation. For individual protection from formaldehyde vapor - filter mask brand AK MAC in the air of industrial premises formaldehyde - 0.5 mg/m3, acrolein - 0.7 mg/m3.

Aldehydes (abbreviated from lat. Alkohol dehidrogenatus) - organic compounds containing aldehyde group. According to the Geneva item names aldehydes produce attach the end of the "al" to the name of a hydrocarbon that forms the skeleton of the molecule, for example SNO - methanal, CH3SNO - ethanol. In paraffin series titles aldehydes often associated with the name of the corresponding acids; thus, CH3SNO - acetic A., CH3CH2SNO - propionic. Benzoic aldehyde is part of glycoside amygdalin contained in the bitter almonds, and other Natural essential oils are composed primarily of unsaturated cyclic A. (aniseed and cinnamaldehyde, vanillin). The most frequently A. is produced by oxidation of alcohols.
Lowest aldehydes are easily dissolved in water, the higher is bad. Some A. have a pleasant smell and used in perfumery industry. Aldehydes are highly reactive compounds are easily oxidized (oxide silver. hydroxide copper) in acid that is used to open a For A. the typical reactions seals, polymerization. Under the action of A. bases, oxidation of one molecule at the expense of others with the formation of acid and alcohol.
This phenomenon, called dismutation, is in the process of fermentation that occurs under the influence of various enzymes. A. many are initial or intermediate products of organic synthesis. Formaldehyde, for example,a raw material for the synthesis urotropine, acetic aldehyde - for synthesis of chloral hydrate. Some A. (formaldehyde, paraldehyde is recommended, citral) are used in medical practice. A. play a big role in biological processes and is an intermediate products of oxidation amines (formed by the decarboxylation of amino acids) to fatty acids (see Amines).
Aldehydes as industrial poisons. Aldehydes are related to drugs, having a General effect on the body and causing reflex changes of the nervous system in Addition, A. have a strong irritating effect on the mucous membranes of eyes and respiratory tract infections (conjunctivitis, laryngitis, bronchitis and other). With the increasing number of carbon atoms drug action A. vapor increases, irritant - weakens. The lower members of a series, better soluble in water, are mainly in the upper respiratory tract; the higher, the less soluble, affect mainly the deep divisions respiratory tract. Unsaturated aldehydes fatty number (for example, acrolein) have a more pronounced irritating properties than the limit. Getting on the skin, liquid A. cause slight burning and a faint blush. The specified action saturated A. fatty number diminishes with the increasing number of carbon atoms. Formaldehyde causes necrosis of the skin and provides General toxic effect. Unsaturated A. fatty series are similar to the saturated. Acrolein leads to a stronger inflammatory changes than its homologues. Aldehydes are from the body very slowly. Cm. also Poisoning.