DECONTAMINATION

From Big Medical Encyclopedia

DECONTAMINATION — neutralization or removal of toxic agents from a surface or the volume of the infected objects for the purpose of prevention of defeat of people. Is a component special processing (see). Of the toxic agents (TA) on integuments of the person (animals) is called sanitary (veterinary) processing.

The term «decontamination» appeared during World War I (1914 — 1918) after use of toxic agent of yperite. Neutralization of the objects infected with «poison gas» also made contents of the term «decontamination».

The areas infected with O B, structures and defensive works, air, water, food stuffs, arms, vehicles, the military and production equipment, clothes, medical property, etc. can be objects D.

Methods of decontamination are subdivided on chemical, physical and mechanical. Chemical methods at which destruction or transformation of OV into non-toxic products owing to chemical reaction with the decontaminating substances is reached are most effective. At physical. the OV methods evaporations or sorptions (active coal) are removed from the infected objects by washing off by their special washing solutions (OP-7, OP-10) or solvents (gasoline, kerosene, a dichloroethane, etc.). At the same time ABOUT, passing into solution, steam or a sorbed state, partially or completely keep the toxic properties. Mechanical methods D. consist O B from an object dry tampons, cutting of the infected layer or in isolation of the infected surface by the device of floorings and other coverings (sand, sawdust) at a distance.

The choice of a method D. depends generally on a type of OV, its aggregate state, and also on purpose of the infected object and on material, from to-rogo it consists. At infection of objects from nonporous materials resistant OV in aerosol and drop liquid state (V-gases, yperite, a lewisite) to D. apply hl. obr. chemical methods.

In practice also natural D. («self-decontamination») occurring owing to decomposition of OV and removal them under the influence of factors of the surrounding environment evaporation, hydrolytic decomposition, oxidation by oxygen of air etc. can be used. Duration of infection of objects of OV depends on the OV type, on density and exposure of infection, from meteorol, conditions and penetration depth of O B in various materials, and also from properties of these materials and can fluctuate in considerable limits. So, OV on arms, the equipment and on the area can remain within several days, in the winter in the summer — within weeks and even months from the moment of infection.

It is accepted to call the chemical compounds capable to react with OV as a result of which low-toxic or non-toxic products are formed the decontaminating substances. Usually they are applied in the form of the decontaminating compoundings (decontaminators) representing solutions of the decontaminating substances with various additives for increase in shelf stability, improvement of wettability, decrease in temperature of freezing and improvement of other qualities. As the decontaminating substances for OV of dermatovesical action and V-gases preferential use the chemical connections containing active chlorine and being strong oxidizers. Of organophosphorous OV (herd, GD, sarin) it is more preferable to apply alkalis, alcoholates and amines which cause hydrolytic disintegration of OV to non-toxic or low-toxic products to D.

The most known chlorine-containing decontaminating substances applied to D. of various objects infected with iprita, a lewisite and V-gases is the following.

Lime chloride. Contains from 32 to 36% of active chlorine. Apply in a dry form, in the form of gruel (mixes with water 1: 2 on weight) or in the form of chlorine-lime milk (in cultivation 1: 9 on weight) for D. of the area, buildings and defensive works, wooden objects, some types of military equipment.

Dvetretiosnovny salt of calcium hypochlorite. Contains 55 — 60% of active chlorine; in water it is sparingly soluble. Apply in the form of an aqueous slurry in cultivation 1:5 — 1:10 to D. areas, constructions, wooden products.

Monochloramine. Contains apprx. 32% of active chlorine. Water and aqueous-alcoholic solutions apply 10% to D. of various objects, 2 — 5% of water or 5 — 15% spirit solution for D. of skin of the person, 0,2 — 0,5% water solution for processing of mucous membranes of eyes.

Dichloramine T. Contains apprx. 60% of active chlorine; in water we will not dissolve. Apply 10% solution in a dichloroethane to D. of various objects.

Geksakhlormelamin. Contains apprx. 120% of active chlorine; in water it is not dissolved, well dissolved in a dichloroethane. Apply 5% solution in a dichloroethane to D. of various objects.

Among alkaline decontaminators of the objects infected with sarin OV the following is most known.

Caustic soda. Water solutions apply 5 — 10%.

Ammonia. Water solutions apply 10 — 12%.

Sodium sulfide. Water or aqueous-alcoholic solutions apply 5 — 10% to D. of metal, glass and porcelain products, and in the firm (crushed) look — to D. of the soil.

As decontaminators of V-gases, a lewisite, sarin also some peroxides, e.g. by 1 — 3% solutions of hydrogen peroxide, 2 — 3% solutions of potassium permanganate can be applied.

For full D.'s providing various compoundings of polyvalent decontaminators are offered O B. To it, in particular, belong the decontaminating solution No. 1 (5% solution of hexachlormelamine in a dichloroethane) which is used for D. of the weapon, the equipment, transport and other objects infected with iprita, a lewisite, V-gases and the decontaminating ammoniac and alkaline solution No. 2-ashch (the water solution containing 2% of caustic soda, 5% monoethanol of amine and 20% of ammonia) which intends for D. at infection with organophosphorous OV like sarin.

Technical means of decontamination

of the objects infected with OV use various technical means accepted on equipment of troops and chemical divisions To D.

First-aid antigas kit (see) it is applied to D. of the toxic agents which got on skin of the person.

First-aid Vent Kit (FAVK). Represents a metal case, in Krom there are two glass ampoules: one, filled with the decontaminating solution No. the 1, second — solution No. 2-ashch; in a cover of a case there are several tissues. Use for D. of an individual weapon. Delete with a pure tissue from weapon visible drops of OV then wipe weapon with the napkins moistened in solution No. 1, and then in solution No. 2-ashch.

Artillery vent set (A-recreation center). Consists of a metal case, in Krom banks with solvent for the decontaminating solution No. 1 and two cases with the corresponding amount of hexachlormelamine (solution is prepared just before processing), two banks with the decontaminating solution No. 2-ashch, two brushes, two scrapers for removal of dirt and rags are placed two. It is intended for D. of arms and technicians. Just before processing of weapon or the equipment it is necessary to prepare solution No. 1 (in one of cans with solvent dissolve contents of a case). Rags remove from a surface of a drop of OV and wipe the infected places with the brushes moistened at first in solution No. 1, and then in solution No. 2-ashch.

Rantsevy decontamination apparatus of RDP-4V. It is intended for D. of weapon, the equipment and other objects. Before work the tank (volume of 8,5 l) is filled with one of the decontaminating solutions, and then through a hose with a fire engine and a brush given on the decontaminated object pressure of the air forced in a tank by the manual pump.

Automobile set of special processing (DK-4). Consists of the gas-liquid device connected to an exhaust pipe of the car. By means of a set D. of machines and the equipment by a hot stream of solution through a hose and a fire engine with a brush is made.

Mobile refueling station (ARS). Apply to D. of the equipment, weapon, transport and the area. For processing of the infected objects the ARS tank (capacity of 2,5 m 3 ) fill with the decontaminating solution which under the pressure of 2 atm moves on the decontaminated objects through hoses and fire engines with brushes. It is at the same time possible to process up to 5 objects.

Autovent car (ADM). Has two capacities established in a body of the truck, and system of hoses with fire engines and brushes through which the decontaminating solutions No. 1 and No. 2-ashch can move on the processed objects. Use for D. of weapon, military equipment and other objects.

Suspended decontamination apparatus (PDP-53). It is intended for D. to the area by dry decontaminators. The device is installed by truck. The bunker it is filled with a decontaminator which by means of the sowing mechanism is sprayed on the infected site of the area. For D. the area can use also water-jetting vehicles, graders, bulldozers, snowplows.

Autovent station (AGV-ZM). It is intended for D. of regimentals, footwear, individual means of protection with use of a steam-air and ammoniac method. AGV-ZM consists of the power machine, two vent cars, on each of which three vent cameras with the generator of ammonia (ammonia is received from bicarbonate ammonium or ammonium hydroxide), and the subsidiary car are mounted. The power machine is equipped with installation for providing vent cameras with a hot air and steam. As a result of moistening and heating of the objects placed in the vent cells there is hydrolytic decomposition of OV which are available on them. Ammonia is intended to hl. obr. for neutralization formed at the same time to - the t able to destroy fabric. The clothes after such D. are subject a gigabyte. to washing. The clothes from sukonnobumazhny fabrics are decontaminated at t ° 100 °, leather and sheepskin products — at t ° 60 °. D.'s duration depends on temperature in the camera and the OV type.

Buchilny installation (BU-4M). It is used for D. of clothes from cottons, individual means of protection, soft stock. BU-4M two metal buchilnik, a press for an extraction of clothes after boiling turn on, the manual pump for filling of a buchilnik water. Of clothes make boiling.

Actions for D. will organize depending on character, appointment and accessory of the infected objects.

Depending on conditions, existence of time and D.'s equipment of weapon, the equipment, transport and other objects can be partial or full.

Partial D. is carried out during performance of a fighting task and consists in neutralization of those parts and units, the contact with to-rymi cannot be stopped under the terms of a situation.

Full D. is carried out, as a rule, in regions of an arrangement of parts (divisions), and also on points of special processing (PUSO) developed by chemical service.

Of weapon, military equipment, transport, fighting positions, defensive works commanders of parts together with divisions of chemical troops will organize. Of objects in settlements and the cities will be organized by the respective headquarters and chemical service of bodies of civil protection with involvement of the population.

Of water and water sources the engineering service, and food stuffs — food service carries out. The medical service exercises control of D.'s completeness of water and food, draws the conclusion about suitability them to the use; controls observance of safety measures by production of vent works: will organize and makes D. of medical property, carries out sanitary cleaning struck and the patients who arrived on stages of medical evacuation.

Of water is carried out only when it is impossible to extract the water suitable for drink. For reliable neutralization water is chlorinated in the beginning, coagulated, and then passed via special filters. For D. of a small deposit of moisture use the universal filter (UNF-30) with a productivity of 30 l/hour or the tkanevougolny filter (TUF-200) with a productivity of 200 l/hour. On points of water supply developed by engineering service D. of water is carried out by the mechanized autofiltration plant (MAFS-7500) with a productivity of 3600 l/hour. Liberation of water from all OV can be reached filtering it via the filters containing karboferrogel. Of water can be applied by boiling only in cases of insignificant infectiousness and when it is precisely known that hydrolysates of O B are not toxic. The water infected with a lewisite cannot be decontaminated by boiling since the products which are formed at its hydrolysis contain arsenic and are toxic.

The food stuffs which are in a container, hermetic, not permeable for OV, can be used after D. of a container (cans, etc.). Small stocks of the infected products which are not protected from O B by a container destroy. Of large numbers of food make mechanical removal of the infected layers, airing for D., apply culinary processing, technological processing. Of the firm and loose food stuffs infected with drop and liquid OV begin with mechanical removal of a layer on penetration depth of drops of OV, then products air. The final stage is culinary (technological) processing. The food infected with couples of OV is decontaminated by airing with the subsequent culinary processing.

Water and food after D. can be used for designated purpose only in the presence of the decision about suitability to the use received from medical service of troops, and in GO — bodies state a dignity. supervision.

The medical objects and medicines which are in packaging, hermetic, not permeable for OV, can be used for designated purpose after D. of a container. Different metal objects can be decontaminated by regular decontaminators (solutions No. 1 and No. 2-ashch) or by numerous washing by pure solvents with the subsequent boiling in soda solution. The medical rubber goods (catheters, drainage tubes), bandage infected with drop and liquid OV, and also not packaged D.'s medicines are not exposed, and are destroyed. The sanitary property, a stretcher, tents and transport can be decontaminated by general means. The regimentals struck, as a rule, for D. go to vent points.

The persons involved for carrying out vent works shall be in individual means of protection and observe the established safety measures, and upon termination of work to undergo full sanitary cleaning.

The chemical service provides with D.'s means (decontaminators, technical means D.) of army (formation of GO).

See also Individual means of protection , Toxic agents .


Bibliography: Alexandrov V. N. Toxic agents, M., 1969, bibliogr.; Gradoselsky V. V. Nuclear, chemical and bacteriological weapon and protection against it, M., 1970; To and r and to the h and-e in N. I. Toksikologiya O B and protection against weapons of mass destruction, Tashkent, 1973; To about r about l of e in R. V. Sanitarno-himi-cheskaya examination of water and foodstuff, M., 1971, bibliogr.; Sanitary hi-micheskaya protection, Pathology, clinic and therapy of gas poisonings, under the editorship of Yu. V. Drugov, M., 1959; Erased l and R.'s N of H., E m of e of l I am a N about in V. I. and Zimin V. I. Chemical weapon and protection against it, M., 1971, bibliogr.

H. N. Savchenko.

Яндекс.Метрика