Despite the fact that we literally bathe in them, chemicals are not famous for a good reputation. Some of them can be useful, but almost everything will be poison under certain conditions.

Chemicals and reagents that you find on the list below will be dangerous even in ideal conditions. Extremely dangerous.

Bromistic ethidium

Modern biologist should know the principles of working with DNA. The problem is that DNA is completely invisible in concentrations that most people use. If you want to isolate DNA fragments, they need to paint. Bromistic ethidium is perfect as a DNA dye. It is beautifully fluorescents and closely cling to DNA. What else is needed for happiness? Maybe this connection does not cause cancer?

Bromichy ethidy color DNA, sinking between pairs of bases. This leads to a disruption of the integrity of DNA, since the presence of the ethidium bromide causes the stress in the structure. Places of breaks are becoming sites for mutations.

But mutations, as you know, are most often undesirable. Moreover, you need to use ultraviolet light, another carcinogenic agent to visualize the dye, which clearly will not make the component safer. Many DNA scientists prefer to use more secure compounds for deoxyribonucleic acid.

Dimetalkadmium

Lead, mercury and all their friends cause various health problems, falling into the human body. In some forms, these heavy metals can pass through the body without absorbing. In others, they are easily captured. Once inside, they begin to cause problems.

Dimethyldamium causes serious skin burns and eye damage. It is also a poison that accumulates in tissues. In addition, if physiological effects are not enough, this chemical is fuel in liquid and gaseous forms. Interaction with air is enough to set fire to it, and water only aggravates the burning process.

In the process of burning dimetalkadmi produces cadmium oxide - another substance with unpleasant properties. Cadmium oxide causes cancer and flu-like illness called "Foundry Fever".

Vx.

VX, as the VENOMOUS Agent X is called ("X"), this is a chemical substance that has not found applications outside of chemical weapons. Developed by the English research military station in the portion, this substance is odorless, without taste is mortally even in the amount of 10 milligrams. The British government traded information about VX with American in exchange for the process of creating thermonuclear weapons.

VX easily absorbed into the skin. In addition, it does not immediately disintegrate in the environment, therefore, the attack with the use of VX will lead to long-term consequences. Clothes that was worn during the influence of a substance will be enough to poison anyone who has entered into contact with it. The impact of VX instantly kills, causing cramps and paralysis. Death occurs in the process of failure of the respiratory system.

Sulfur trioxide

Sulfur trioxide is a sulfuric acid precursor, which is also necessary for some sulfication reactions. If the sulfur trioxide was not useful, not a single sensible scientist would hold it with him. Sulfur trioxide is extremely caustic when comes into contact with organic matter.

Interacting with water (which is most of our body), it creates sulfuric acid with heat release. Even if he did not get directly on your flesh, even nearby be very dangerous. Sulfuric acid pairs do bad with light. Sulfur trioxide spilling on organic material like paper or wood generates toxic fire.

Batrahotoxin

Batrahotoxin is a complex molecule that is so fatal that one 136 millionth gram of this substance will be fatal for a 68-kilogram person. So that you understand it is about two salt granules. Batrahotoxin is among the most dangerous and toxic chemicals.

Batrahotoxin binds to sodium channels in nerve cells. The role of these channels is vital in muscle and nerve functions. Holding these channels open, the chemical is eliminating any muscle control from the body.

Batrahotoxin found on the skin of tiny frogs whose pois was used for poisoned arrows. Some of the Tribes of the Indians looked down the tips of the arms into the poison released by frogs. Darts and arrows paralyzed prey and allowed the hunters calmly take it.

Dioxidefluoride

Dioxidefluoride is a terrible chemical having a charming name FOOF, since two oxygen atoms are attached to two fluoride atoms. In 1962, Chemik A. G. Schrang published work entitled "Chemical properties of dioxidafluoride". And although this name does not seem to be frightening, the experiments of Streng were definitely those.

FOOF is made at very low temperatures, since it breaks down at a boiling point of about -57 degrees Celsius. During his experiments, Schret found that FOOF explodes, engaging with organic compounds, even at temperatures -183 degrees Celsius. Interacting with chlorine, FOOF is strongly exploded, and contact with platinum leads to the same effect.

In short, in the section of the results in the work of Streng, there were many words "outbreak", "spark", "explosion", "strongly" and "fire" in different combinations. Do not forget that all this happened at temperatures at which most chemicals are essentially inert.

Calassium cyanide

Cyanide is a simple molecule, just a carbon atom, linked three times with a nitrogen atom. Being a small, cyanide molecule can leak into proteins and make it very bad. Especially cyanide likes to bind to iron atoms in the center of hematoproteins.

One of the hemoproteins is extremely useful for us: hemoglobin, protein carrying oxygen in our blood. Cyanide eliminates hemoglobin on the ability to carry oxygen.

When potassium cyanide comes into contact with water, it is divided into hydrogen cyanide, which is easily absorbed by the body. This gas smells like bitter almonds, although not everyone can teach it.

Because of the rapid response, potassium cyanide was often used as a means for [Roskomnadzor] by many people. British agents of the Second World War Wearing Cyanide Tablets in case of capture, and many high-ranking Nazis also used potassium cyanide capsules to avoid justice.

Dimethelrtut

Two drops of dimethylrituti - and that's it.

In 1996, Karen Wetterthaan examined the effects of heavy metals on the organisms. Heavy metals in their metal form are quite poorly interacting with alive organisms. Although it is not recommended, it is quite possible to lower your hand into liquid mercury and successfully remove it.

Therefore, to introduce mercury into DNA, Wettehan used dimethylitut, mercury atom with two attached organic groups. In the course of the work, Wettekhan dropped a drop, maybe two, on their latex glove. After six months, she died.

Wettechan was an experienced professor and accepted all the recommended precautions. But dimmingly leaked through gloves in less than five seconds, and through the skin - less than fifteen. The chemical did not leave any explicit traces and Woverthaan noticed side effects only a few months later, when it was too late to be treated.

Trifluoride chlorine

Chlorine and fluorine separately unpleasant elements. But if they are combined into chlorine trifluoride, everything becomes even worse.

Chlorine trifluoride is such a corrosive substance that it will not be able to store it even in glass. This is such a strong oxidant that he can set fire to things that do not even burn in oxygen.

Even the ashes of things burned in an oxygen in the atmosphere will light up under the action of chlorine trifluoride. He does not even need a source of ignition. When 900 kilograms of chlorine trifluoride spilled as a result of an industrial accident, this chemical was dissolved 0.3 meters of concrete and a meter of gravel.

The only (relatively) safe way to store this substance is a metal container, which has already been treated with fluorine. Thus, the fluorine barrier is created, with which the chlorine trifluoride does not react. Meeting with water, chlorine trifluoride instantly explodes with heat excretion and plastic acid.

Hydrofluoric acid

Anyone who worked in the field of chemistry, heard the bikes about fluoride hydrochloric acid. In the technical sense, this is a weak acid that is not easy to part with its hydrogen ion. Therefore, the quick chemical burn will get quite difficult from it. And this is the secret of her cunning. Being relatively neutral, gliding acid can pass through the skin without notifying you, and get into the body. And being in place, the plastic acid is starting to work.

When the acid gives his proton, the fluorine remains, which reacts with other substances. These reactions increase as a snowball, and fluorine sows terrible chaos. One of the favorite fluorine purposes is calcium. Therefore, the plastic acid leads to the death of bone tissue. If you leave the victim without treatment, death will come long and hurt.

The rapid development of the chemical industry and the chemicalization of the entire national economy led to a significant expansion of production and application in the industry of various chemicals; The range of these substances was also significantly expanded: many new chemical compounds were obtained, such as monomers and polymers, dyes and solvents, fertilizers and pesticides, combustible substances, etc. Many of these substances are not indifferent to the body and, getting into the air of work space, directly On working or inside their organism, they may adversely affect the health or normal life of the body. Such chemicals are called harmful. Depending on the nature of their action, depending on the nature of their action are divided into irritating substances, toxic (or poisons), sensitizing (or allergens), carcinogenic, etc. Many of them have simultaneously by several harmful properties, and above all to one extent toxic, so the concept " Harmful substances are often identified with "toxic substances", "poisons", regardless of the presence of other properties in them.

Poisoning and diseases arising from the effects of harmful substances in the process of performing work in production are called professional poisoning and diseases.

Causes and sources of excretion of harmful substances.Harmful substances in industry can be part of raw materials, ultimate, side or intermediate products of a particular production. They can be three species: solid, liquid and gaseous. The formation of dust of these substances, vapors and gases is possible.

Toxic dust is formed as a result of the same reasons as conventional dust described in the previous section (grinding, combustion, evaporation, followed by condensation), and are released into air through open opening, poorness of dusting equipment, or when crossing them in an open way.

Liquid harmful substances are most often seeping through looseness in the equipment, communications, are sprayed when they are discovered from a single container to another. At the same time, they can get directly on the skin of working and have an appropriate adverse effect, and in addition, to pollute the surrounding exterior surfaces of the equipment and fences that become open sources of their evaporation. With such contamination, large surfaces of evaporation of harmful substances are created, which leads to a rapid saturation of air in pairs and the formation of high concentrations. The most frequent causes of leakage of liquids from equipment and communications are the separation of gaskets in flange compounds, loosely fitted taps and valves, not enough compacted seals, metal corrosion, etc.

If liquid substances are in open containers, from their surface also evaporates and the establishment of the formed vapors in the air of work premises; The greater the open surface of the fluid, the more it evaporates.

In the event that the liquid partially fills the closed container, the formed pairs are saturated to the limit of the unfilled space of this container, creating very high concentrations. In the presence of strokes in this container, the concentrated pairs can penetrate the atmosphere of the workshop and pollute it. The output of vapors increases if the container is under pressure. Massive vapor sections also occur at the time of filling with the container with a liquid, when the fastened liquid displaces the accumulated concentrated pairs from the container, which through the open part or the looseness go to the workshop (if the closed container is not equipped with a special air output beyond the workshop). The selection of vapors from closed containers with harmful liquids occurs when opening covers or hatches to monitor the process of process, mixing or loading additional materials, sampling, etc.

If gaseous harmful substances are used as raw materials or are obtained as ready or intermediate products, they, as a rule, stand out in the air of work space only through random loosening in communications and equipment (since if they have them in the devices, the latter cannot even open in short time ).

As a result of the adsorption of gases can settle on the surface of the dust and together with them for certain distances. In such cases, the places of dusting can be simultaneously and places of gas division.

The source of excretion of harmful substances of all three species (aerosol, vapor and gas) is often different heating devices: dried, heating, roasting and melting furnaces, etc. Harmful substances are formed in them due to combustion and thermal decomposition of some products. The selection of them in the air occurs through the working openings of these furnaces and dried, loosening their masonry (progress) and from the heated material removed from them (molten slag or metal, dried products or burnt material, etc.).

The frequent cause of massive distinguishing distinguishes is the repair or cleaning of equipment and communications containing toxic substances with their opening and even more dismantling.

Some vapor and gaseous substances, standing out into the air and polluting it, are sorbed (absorbed) by separate building materials, such as wood, plaster, brick, etc. over time, such building materials are saturated with these substances and under certain conditions (temperature changes and others. ) themselves become sources of their separation in the air - desorption; Therefore, sometimes even with the full elimination of all other sources of distinguishing, elevated concentrations of them in the air can remain for a long time.

Ways of receipt and distribution of harmful substances in the body.The main routes of receipt of harmful substances in the body are respiratory tract, digestive tract and skin.

There is the greatest importance to enter them through the respiratory organs. The toxic dust, couples and gases entered the air are inhaled and penetrated into the lungs. Through the branched surface of bronchiole and alveoli, they are absorbed into the blood. Inhaled poisons have an adverse effect on almost all over the time of operation in a polluted atmosphere, and sometimes even at the end of work, since their suction is still continuing. The poisons received through the respiration organs through the organs throughout the body, as a result of which their toxic action can affect the most varied organs and tissues.

Harmful substances come to the digestion organs during the swallowing of toxic dust, located on the mucous membranes of the oral cavity, or by bringing them there with contaminated hands.

The poisons entered into the digestive tract throughout the path are absorbed through the mucous membranes into the blood. Basically, suction occurs in the stomach and intestines. The blood entered through the digestive bodies of the poison is directed to the liver, where some of them are delayed and partially neutralize, because the liver is a barrier for applicants through the digestive tract of substances. Just passing through this barrier, the poisons go into common bloodstream and they are spread throughout the body.

Toxic substances with the ability to dissolve or dissolve in fats and lipoids can penetrate the skin when contaminated by these substances, and sometimes in the presence of them in the air (to a lesser extent). Penetrated through the skin of the poisons immediately enter the overall bloodstream and they are dealt with the body.

We entered the body in one way or another, the poisons can be relatively uniformly distributed over all organs and tissues, having a toxic effect on them. Some of them accumulate mainly in some alone tissues and organs: in the liver, bones, etc. Such places of the predominant accumulation of toxic substances are called the poison depot in the body. For many substances, certain types of tissues and organs are characterized, where they are deposited. Delayed poisons in the depot can be both short-term and longer - up to several days and weeks. Gradually, leaving the depot to the overall bloodstream, they can also have a definite, as a rule, a weak toxic effect. Some unusual phenomena (alcohol intake, specific food, disease, injury, etc.) can cause a faster elimination of poisons from the depot, as a result of which their toxic effect is manifested more pronounced.

The selection of poisons from the body is mainly through the kidneys and intestines; The most volatile substances are also released through the lungs with exhaled air.

Physico-chemical properties of harmful substances.The physico-chemical properties of harmful substances in the form of dust are the same as conventional dust.

If solid, but soluble harmful substances are used in production in the form of solutions, their physicochemical properties will largely be similar to the properties of liquid substances.

When, harmful substances enter the skin and mucous membranes, the superficial tension of the fluid or solution, the consistency of the substance, chemical affinity with fats and lipoids covering the skin, and the ability to dissolve fats and lipoids, has the greatest hygienic value from physicochemical properties.

Substances of liquid consistency and liquid with a small surface tension when entering the skin or mucous membranes well wet them and contaminate the larger area, and, on the contrary, liquids with a large surface tension, thick consistency (oily) and solids, hitting the skin, more often It remains on it in the form of droplets (if they are not rubbed) or dust (solids), contacting the skin on a limited area. Thus, substances with small surface tension and liquid consistency are more dangerous or thick consistency and with a large surface tension.

Substances close to their chemical composition to fat and lipoids, when entering the skin relatively quickly dissolve in fats and lipoids of the skin and together with them pass through the skin inside the organism (through its pores, swing and sweat glands). Many liquids have the ability to dissolve fats and lipoids themselves and due to this relatively quickly penetrate the skin. Consequently, substances possessing these properties are of greater danger than others with opposite physicochemical properties (with equal other conditions).

With respect to contamination with harmful pairs or gas gases, the volatility of substances, the elasticity of its vapor, boiling point, share, chemical composition have a volatility.

The volatility of substances call the ability to evaporate a certain amount of time per unit of time at a given temperature. The volatility of all substances is compared with the vulgarity of the ether under the same conditions adopted per unit. The substances with a small volatility are slower than the air than substances with high volatility, which can relatively quickly evaporate, creating high concentrations of them in the air. Consequently, substances with increased volatility represent a greater danger than with small. With increasing temperature of the substance, its volatility increases.

An important hygienic value is elasticity or a pair of toxic fluid pressure, i.e. The limit of air saturation at a certain temperature. This indicator is expressed, as well as air pressure, in millimeters of a mercury pillar. For each liquid, the elasticity of steam for certain temperatures is the value constant. The degree of possible saturation of the air in pairs depends on this value. The higher the elasticity of the steam, the greater the saturation and the higher the concentrations can be created when evaporating this liquid. With increasing temperature, the elasticity of steam increases. This property is especially important to consider with long-term evaporation of toxic substances, when the selection of vapors occurs until the air is completely saturated, which is often observed in closed, poorly ventilated rooms.

The boiling point that is permanent for each substance also determines the relative risk of this substance, since evaporation of it depends on the usual temperature conditions of the workshop. It is known that the most intense vaporization, i.e. Evaporation, occurs when boiling when the fluid temperature rises to this permanent value. However, a gradual increase in liquid evaporation occurs as its temperature approaches the boiling point. Consequently, the lower the boiling point of the substance, the smaller the difference between the last and normal temperature of the workshop, the closer the temperature of this substance (if it is additionally cooled or not heated) to its boiling temperature, so above and its evaporation. Thus, the substances with low boiling point are of greater danger than high-boiling.

The density of the substance is one of the factors determining the distribution of the vapor of this substance in the air. Pairs of substances with a density less than air density under the same temperature conditions rise into the upper zone, therefore, passing through a relatively thick layer of air (when highlighting vapors in the lower zone), they quickly mix with it, polluting significant spaces and creating the highest concentrations in the upper zone (If there is no mechanical or natural hood from there). With density of substances, more air density The distinguished pairs accumulates mainly in the lower zone, creating the highest concentrations there. However, it should be noted that this last pattern is often disturbed when the heat generation occurs or the pairs themselves are highlighted in heated form. In these cases, despite the greater density, convection flows of heated air pairs are fond of the upper zone and also contaminate air. All these patterns need to be considered when placing jobs at different levels of the workshop and with exhaust ventilation equipment.

Some of the above physical properties of substances has a significant impact of the state of the external environment, and above all meteorological conditions. For example, an increase in air mobility enhances the evaporation of liquids, an increase in temperature increases the elasticity of vapors and enhances the evaporation, the latter contributes to the latter.

The most significant hygienic value is the chemical composition of harmful substances. The chemical composition of the substance determines its main toxic properties: various substances in their chemical composition have different toxic effects on the body both in character and strength. A strictly defined and consistent dependence between the chemical composition of the substance and its toxic properties is not established, but some connection between them can be installed. Thus, in particular, the substances of one chemical group, as a rule, are largely similar to the nature of their toxicity (benzene and its homologs, a group of chlorinated hydrocarbons, etc.). This sometimes makes it possible to approximately judge the nature of the toxic effect of some new substance in the similarity of the chemical composition. Inside the individual groups similar to the chemical composition of substances, some regularity in changing the degree of their toxicity, and sometimes in the change in the nature of the toxic effects are also revealed.

For example, in the same group of chlorinated or other halogen-substituted hydrocarbons as the number of hydrogen atoms substituted with halogens increases, the degree of toxicity of substances increases. Tetrachloroethane is toxic than dichloroethane, and the last is toxic than chloride ethyl. The addition of nitro or amino groups to aromatic hydrocarbons (benzene, toluene, xylene) instead of the hydrogen atom give them completely different toxic properties.

The identified certain relationships between the chemical composition of substances and their toxic properties were allowed to approach the approximate estimate of the degree of toxicity of new substances on the basis of their chemical composition.

The effect of harmful substances on the body.Harmful substances can have local and overall effect on the body. The local action is most often manifested in the form of irritation or chemical burns of the place of immediate contact with poison; Typically, there is a skin cover or mucous membranes of the eyes, upper respiratory tract and oral cavity. It is a consequence of the chemical effects of an irritant or toxic substance on the living cells of the skin and mucous membranes. In a light form, it is manifested in the form of redness of the skin or mucous membranes, sometimes in their swelling, sensation of itch or burning; In more severe cases, painful phenomena are more pronounced, and changing the skin or mucous membranes can be up to their ulceration.

The general effect of the poison occurs when it penetrates into blood and distribution throughout the body. Some poisons have specific, i.e. The electoral action on certain organs and systems (blood, liver, nervous fabric, etc.). In these cases, penetrating into the body in any way, the poison affects only a certain organ or system. Most poisons have a general-toxic effect or action simultaneously into several organs or systems.

Toxic effects of poisons can manifest itself in the form of acute or chronic poisoning - intoxication.

Acute poisoning arises due to the short-term effects of a significant amount of harmful substance (high concentrations) and is characterized, as a rule, the rapid development of painful phenomena - symptoms of intoxication.

Prevention of professional poisoning and diseases.Activities for the prevention of professional poisoning and diseases should be directed, first of all, to maximize the elimination of harmful substances from production by replacing them with non-toxic or, at least less toxic products. It is also necessary to eliminate or maximize the toxic impurities in chemical products, for which in the approved standards for these products it is advisable to indicate the limits of possible impurities, i.e. Conduct their hygienic standardization.

In the presence of several types of raw materials or technological processes to obtain the same product, it is necessary to give preference to those materials containing less toxic substances or the available substances have the lowest toxicity, as well as the processes in which toxic substances or the latter are not distinguished toxicity.

Special attention should be paid to the use in the production of new chemicals, the toxic properties of which have not yet been studied. Among such substances may also be highly toxic, so the possibility of professional poisoning is not excluded. In order to avoid this, all newly developed technological processes and newly obtained chemicals should simultaneously study with hygienic positions: to assess the risk of excretion of the harm and toxicity of new substances. All innovations and envisaged preventive measures must be coordinated with local sanitary supervision authorities.

Technological processes using or the possibility of formation of toxic substances should be able to be continuous to eliminate or reduce to a minimum excretion of harm at intermediate stages of the technological process. For the same purpose, it is necessary to use the most sealed technological equipment and communications in which toxic substances may be. Special attention should be paid to maintaining tightness in flange compounds (apply stripping resistant to this substance), in closing hatches and other working openings, gland seals, samplers. If leakage or knocking out of vapors and gases from the equipment is found, urgent measures must be taken to eliminate the existing stuff in equipment or communications. To load raw materials, as well as unloading finished products or by-products containing toxic substances, you should use sealed feeders or closed pipelines so that these operations are made without opening equipment or communications.

Air supplied during the loading of tanks with toxic substances should be discharged by special pipelines (air) beyond the workshop (as a rule, to the upper zone), and in some cases, when extruded out, especially toxic substances are subjected to pre-purification from harmful substances or neutralization, disposal, and so Further.

The technological mode of operation of equipment with the content of toxic substances in it is expedient - to maintain it so that it does not contribute to the enhancement of the excretion of the harm. The greatest effect in this respect provides maintenance of some discharge in the devices and communications, in which even in case of tightness impairment, air from the workshop will be absorbed into these devices and communications and prevent toxic from them. It is especially important to maintain the discharge in the equipment and devices that have permanently open or lean closed working openings (ovens, dried, etc.). At the same time, the practice shows that in cases where, under the terms of the technology, maintaining inside the devices and in communications a particularly high pressure, knocking out of such devices and communications is either not observed completely or it is quite negligible. This is explained by the fact that with significant leaks and knocking, high pressure drops sharply and disrupts the technological process, i.e. Without due tightness it is impossible to work.

Technological processes related to the possibility of harmful discharge should be maximized and automated, with remote control. This will eliminate the danger of direct contact of workers with toxic substances (contamination of the skin, overalls) and remove jobs from the most dangerous zone of the main technological equipment.

Significant hygienic importance are timely planning and preventive repair and cleaning of equipment and communications.

The cleaning of technological equipment containing toxic substances should be performed mainly without its opening and dismantling or, at least, with minimal volume and opening time (purge, flushing, cleaning through the glands, and the like.). Repair of such equipment is appropriate to carry out on special, isolated from the overall room stands equipped with reinforced exhaust ventilation. Before dismantling the equipment, both for the delivery of it on the repair stand, and for repairing on the spot, it is necessary to free it completely from the content, then blow it well or washed to completely remove toxic residues.

If it is impossible to complete the separation of harmful substances into the air, measures of sanitary equipment must be used and, in particular, ventilation. The most appropriate and greater hygienic effect is the local exhaust ventilation, removing harmful substances directly from the source of their selection and not allowing them to spread around the room. In order to increase the efficiency of local exhaust ventilation, it is necessary to maximize the sources of distinguishing of the harm and exhaust from these shelters.

Experience shows that to prevent knocked out of harmful substances, it is necessary that the exhaust to provide air seats through open opening or looseness in this shelter at least 0.2 m / s; With extremely and especially dangerous and volatile substances for a greater guarantee, the minimum suction rate increases to 1 m / s, and sometimes more.

Community ventilation is applied in cases where there are scattered sources of harmful discharges, which are practically difficult to fully equip local suction, or when local exhaust ventilation for any reason does not provide full capturing and removing the distinguished harmfulness. It is usually equipped in the form of suns from the maximum accumulation of harm with the compensation of the air removed by the influx of the outer air supplied, as a rule, into the working area. This type of ventilation is calculated to dilute the workmen that stand out in the air to safe concentrations.

To combat toxic dust, in addition to the outlined general technological and sanitary and technical measures, are also used as described inquiry measures.

The planning of industrial buildings in which harmful allocations are possible, their architectural and construction design and placement of technological and sanitary equipment should provide, first of all, the preferential entry of both natural and artificial means of fresh air on the main jobs in the service area. To do this, it is advisable to place similar production in miniature buildings with opening window openings for the natural entry into the workshop of the outer air and with the location of the areas of service and stationary workplaces mainly in the outer walls. In cases of possible allocation of particular toxic substances, jobs are placed in closed consoles or isolated control corridors, and sometimes the most dangerous equipment for gas supplies equipment is isolated. To exclude the danger of combined action on working multiple toxic substances, it is necessary to make the production sections with different intimidations from each other from each other, as well as areas where there are no harmful sections. At the same time, the distribution of inflows and extracts of the ventilation air should include a steady subpoint in pure or less contaminated by harmful discharges and discharge in more ridden.

For the inner cladding of floors, walls and other surfaces of work premises, such construction materials and coatings should be selected that would not sorbitize toxic pairs or gases in the air and would not be permeable for liquid toxic substances. With respect to many toxic substances, oil and perchlorvinyl paints, glazed and metala tiles, linoleum and plastic coatings, reinforced concrete and other are equipped with such properties.

Above the general principles of recovery of working conditions when working with harmful substances; Depending on the hazard class, the latest use of them in each specific case may be different, and some of them also recommended a number of additional or special events.

So, for example, sanitary standards for the design of industrial enterprises when working with harmful substances 1 and 2 hazard classes, it is required to place technological equipment that can distinguish these substances in insulated cabins with remote control from remotes or operator zones. With the presence of 4 grade hazards, air seats are allowed into adjacent premises and even partial recycling it if the concentration of these substances does not exceed 30% of the MPC; With the presence of substances 1 and 2 hazard classes, air recirculation is not allowed even during non-working time and the blocking of local exhaust ventilation with the operation of technological equipment is envisaged.

All of the above measures are mainly aimed at preventing the air pollution of the working premises of toxic substances. The criterion for the effectiveness of these activities is to reduce the concentrations of toxic substances in the air of the work premises to their extremely permissible values \u200b\u200b(MPC) and below. For each substance, these values \u200b\u200bare different and depend on their toxic and physicochemical properties. The basis of their establishment is the principle that the toxic substance at the level of its maximum permissible concentration should not have any adverse effects on working, detected by modern methods of diagnosis, with an unlimited period of contact with it. In this case, a certain reserve coefficient is usually envisaged for more toxic substances.

To control the state of the air, the organization of measures to eliminate the detected hygienic disadvantages and, if necessary, the provision of first aid for poisoning on large chemical, metallurgical and other enterprises has created special gas carriers.

For a number of harmful substances, especially 1 and 2 hazard classes, automatic gas analyzers are used, which can be signed with a recording instrument that register concentrations throughout the change, day, etc., as well as with sound and light signal that notifies the exceedment of the MPC, With the inclusion of emergency ventilation.

In cases of the need for any work at the concentrations of toxic substances exceeding their maximum permissible values, somehow: the elimination of accidents, repair and dismantling equipment, etc., it is necessary to use individual protective equipment.

To protect the skin, hands usually use rubber or polyethylene gloves. From the same materials, breakers and aprons are made to prevent the wetting of overalls toxic fluids. In some cases, skin cover of hands can be protected from toxic fluids with special protective ointments and pasta, which hands are lubricated before work, as well as so-called biological gloves. The latter are a thin layer of the film that is formed during the drying of the volatile deficient special compositions of the collodia type. Eyes are protected from splashes and dust of irritating and toxic substances using special glasses with a tightly adjacent soft rim.

If you get potent substances to the skin or mucous membranes of the eye, the oral cavities must be immediately riveted with water, and sometimes (with alkali eating eating or strong acids) and neutralizing the neutralizing solution (for example, acid - weak base, and alkali is weak acid).

With contamination of the skin, difficult or coloring substances cannot be washed off with different solvents used in industry, since most of them in their composition have toxic substances, therefore they themselves can irritate the skin or even penetrate it by causing a general toxic effect. For this purpose, use special detergents. At the end of the shift, workers must take a warm shower and change clothes into clean home clothing; In the presence of highly toxic and impregnating clothes of substances, it is necessary to warm up to complete linen.

In those production, where, after conducting and clearly compliance with all preventive measures, there is still a certain risk of possible exposure to toxic substances that are working in privileges and compensation, which are provided for by the norms depending on the nature of production.

When entering the work on which there is a danger of contact with toxic substances, workers undergo a preliminary medical examination, and during operation with chronic action substances - a periodic medical examination.

Currently, about 7 million chemicals and compounds are known (hereinafter referred to as a substance), of which 60 thousand are used in human activity. In the international market, 500 ... 1000 new chemical compounds and mixtures annually appear.

The substance is harmful, which, when contacting the human body, can cause injuries, diseases or deviations in a state of health, detected by modern methods, both in the process of contact with it and in the long-term deadlines of the present and subsequent generations.

Chemicals (organic, inorganic, element- organic), depending on their practical use are classified on:

Industrial poisons used in production: for example, organic solvents (dichloroethane), fuel (propane, butane), dyes (aniline);

Yadochimikats used in agriculture: pesticides (hexahloran), insecticides (carboofos), etc.;

Medicines;

Household chemicals used in the form of food additives (acetic acid), sanitation, personal hygiene, cosmetics, etc.;

Biological vegetable and animals of the poisons, which are contained in plants and mushrooms (aconite, cicut), in animals and insects (snakes, bees, scorpions);

Poisoning substances (s): Zarin, Iprit, phosgene, etc.

Poison properties can show all substances, even such as a cooking salt in large doses or oxygen at elevated pressure. However, it is customary to belong to poisons that their harmful effects exhibit under normal conditions and in relatively small quantities.

The industrial poisons include a large group of chemicals and compounds, which in the form of raw materials, intermediate or finished products are found in production.

In the body, industrial chemicals can penetrate through respiratory organs, gastrointestinal tract and intact skin. However, the main way is the lungs. In addition to sharp and chronic professional intoxication, industrial poisons may cause a decrease in the body's stability and an increased overall incidence.

Household poisonings most often occur when poison in the gastrointestinal tract (keriformicates, household chemicals, medicinal substances). Acute poisoning and diseases are possible when entering the poison directly into the blood, for example, in the bite of snakes, insects, with injections of medicinal substances.

The toxic effect of harmful substances is characterized by indices of toxicometry, in accordance with which substances are classified on extremely toxic, highly toxic, moderately toxic and small-toxic. The effect of the toxic effect of various substances depends on the amount of substance that has fallen into the body, its physical properties, the duration of the receipt, the chemical of interaction with biological media (blood, enzymes). In addition, the effect depends on gender, age, individual sensitivity, ways to enter and eliminate, distribution in the body, as well as meteorological conditions and other concomitant environmental factors.

The poisons along with the general possess electoral toxicity, i.e. they represent the greatest danger to a certain organ or system of the body. In electoral toxicity, poisons are distinguished:

Cardiac with predominant cardiotoxic effect; This group includes many drugs, vegetable poisons, metals salts (barium, potassium, cobalt, cadmium);

Nervous, causing violation of predominantly mental activity (carbon monoxide, phosphorodorganic compounds, alcohol and its surrogates, drugs, hypnotic drugs, etc.);

Hepatic, among which chlorinated hydrocarbons, poisonous mushrooms, phenols and aldehydes should be highlighted;

Renal - compounds of heavy metals ethylene glycol, oxalic acid;

Blood - aniline and its derivatives, nitrites, arsenic hydrogen;

Pulmonary - nitrogen oxides, ozone, phosgene, etc.

The danger of a substance is the likelihood of adverse effects of effects in real conditions for the production or application of chemical compounds.

Poisoning proceeds in acute and chronic forms. Acute poisonings are more often group and occur as a result of accidents, breakdowns of equipment and gross violations of labor safety requirements; They are characterized by a short-term effect of toxic substances, no more than within one shift; admission to the body of a harmful substance in relatively large quantities - at high concentrations in the air; erroneous intake inside; Strong contamination of the skin. For example, extremely fast poisoning may occur when exposed to gasoline vapor, high concentrations, hydrogen sulfide and end the death of the respiratory center, if the victim immediately does not take place on fresh air. Nitrogen oxides due to general oxygen action in severe cases can cause coma development, convulsions, a sharp drop in blood pressure.

Chronic poisoning occurs gradually, with long-term admission of poison in the body in relatively small quantities.

Poisoning develops due to the accumulation of the mass of harmful substance in the body (material cumulation) or violations caused by them in the body (functional cumulation). Chronic respiratory poisoning may be a consequence of a one-time or several repeated acute intoxication. To poisons causing chronic poisoning as a result of only functional cumulation include chlorinated hydrocarbons, benzene, gasoline, etc.

When re-influenced by the same poison on a suboxy dose, the course of poisoning can change and except the phenomenon of the cumulation to develop sensitization and addictive.

Sensitization is the condition of the body, in which the repeated effect of the substance causes a greater effect than the previous one. The sensitization effect is associated with the formation of in the blood and other internal environments modified and become alien for the body of protein molecules inducing the formation of antibodies. Substances causing sensitization include beryllium and its compounds, nickel carbonyls, iron, cobalt, vanadium compounds, etc.

With a repeated effects of harmful substances on the body, you can observe the effects of the effects due to addiction. For the development of addiction to chronic effects, it is necessary that its concentration (dose) is sufficient for the formation of a response adaptive reaction and non-sufficient, leading to rapid and serious damage to the body. When evaluating the development of addiction to toxic effects, it is necessary to take into account the possible development of increased resistance to one substances after the impact of others. This phenomenon is called tolerance.

Exist adaptogens (Vitamins, Ginseng, Eleutherococcus) that can reduce the reaction of harmful substances and increase the body's stability to many environmental factors, including chemical. However, it should be borne in mind that addiction is only a phase of the adaptive process, and to catch the face between the physiological norm and the voltage of regulatory mechanisms is not always possible. The overvoltage of the regulation systems leads to the breakdown of adaptation and the development of pathological processes.

Chemical dangerous and harmful production factors are very diverse and divided into various features and criteria.

In sanitary and hygienic practice it is customary to share chemical harmful and dangerous honest factors on chemicals and industrial dust.

The degree and nature of the violations of the normal operation of the human body depends on the path of entering the human body, dose, time of exposure, the concentration of the substance and its solubility, the state of perceive tissue and the body as a whole, atmospheric pressure, temperature and other environmental characteristics.

Consequence actions of harmful substances on organthe bottom may be anatomical damage, permanent or temporary disorders and combined consequences. Many strongly active harmful substances cause physiological disorder in the body without noticeable anatomical damage, impacts on the work of nervous and cardiovascular systems, for general metabolism, etc.

Allocation of harmful substances The air environment is possible when carrying out technological processes and the production of work related to the use, storage, transportation of chemicals and materials, their extraction and manufacture.

Chemicals in the nature of the impact The human body is divided into:

toxic;

annoying;

sensitizing;

carcinogenic;

mutagenic;

• affecting reproductive function.

Most of the productions of harmful substances have generally toxic (widecatter) action. These include aromatic hydrocarbons and their derivatives, tetraethylswin, phosphorran substances, chlorinated hydrocarbons and many others. Her organic compounds have large toxicity.

Annoying action They have acids, alkalis, as well as chloro, fluoro, sermo-, and nitrogen-containing compounds, etc. All these substances combine that when contacting biological tissues, they cause an inflammatory response, and the respiratory and mucous membranes suffer primarily. Eye shell.

TO sensitilizing Substances that, after a relatively short effect on the body, cause increased sensitivity to this substance. With subsequently, even short-term contact with this substance in humans there are rapid reactions, most often leading to skin changes, asthmatic phenomena, blood diseases. Such properties have mercury, platinum, aldehydes, etc. compounds.

Carcinogenic substancesWhen the human body, cause the development of malignant tumors. The products of the oil refining and petrochemical industry, asbestos dust, many hydrocarbons and others have carcinogenic activity.

Mutagenic substances affect the genetic apparatus of embryonic cells of the body. Mutation leads to cell death or to their functional changes. These substances can also cause a decrease in the overall resistance of the body, early aging, as well as other severe diseases. Ethyleneamine, uretan, organic peroxide, and tyrant, formaldehyde, etc. have these properties.

TO substances affecting reproductive functionThese include benzene and its derivatives, servo-carbon, lead, antimony, manganese, kerothymicates, nicotine, mercury compounds, etc.

In separate literary sources toxic substances By physiological influence, divided into:

annoyingwhich act on the surface of the tissues of the respiratory tract, mucous membranes, skin, eyes (acids, alkalis, ammonia, chlorine, sulfur compounds, etc.);

suffocating - physically inert gases, diluting the oxygen content in the air and, thereby disturbing the process of absorption of oxygen with tissues (carbon dioxide, nitrogen, methane, etc.);

somatic poisonswhich cause violation of the activity of the whole organism or its individual systems;

presenting a narcotic action.

There are other classifications harmful substances According to the relevant criteria, for example, according to the predominant action on certain organs and systems of the human body, the largest dose, etc.

On the path of penetration In the human body, they are divided into penetrating through:

respiratory system;

gastrointestinal tract;

skin cover and mucous membranes.

The most dangerous is considered penetration of harmful chemicals through respiratory organsSince the absorption is very intense, and they are across the lungs in a large circle of blood circulation, bypassing the liver.

In the gastrointestinal tract harmful substances Can fall when inhalation of dust and vapor, while eating, if the requirements of personal hygiene are complied with, and during smoking. In this case, the harmful effect of chemicals is partially neutralized by the liver and an acidic stomach medium. However, some of them are still absorbed into the blood through the walls of the intestine and the stomach.

Some chemicals are well soluble in fats can penetrate the body through the skin. By doing this way, they also minimize the liver. The speed of their penetration depends on the state of the skin and meteorological conditions, especially temperature. At the same time, the condition of the organism itself is important, its resistance. People weakened faster exposed to harmful substances, and the consequences of this impact are the most difficult for them.

By degree of impact On the human body, all harmful substances are divided according to GOST 12.1.007 "System of labor safety standards. Harmful substances Classification and general security requirements" Four grades:

• extremely dangerous;
• high-hazard;
• moderately dangerous;
• low hazard.

It should be borne in mind that substances belonging to low hazard, with long-term exposure and high concentrations can cause severe poisoning.

Couples, gases, liquids, aerosols, chemical compounds, mixtures (further substances) when contacting a person's body can cause changes in a state of health or illness.

The effects of harmful substances per person may be accompanied by poisoning and injuries.

Currently, more than 7 million chemicals and compounds are known, of which about 60 thousand are used in human activity.

Classification and types of harmful substances

By chemical structure Harmful substances can be divided into the following groups:

• organic compounds (aldehydes, alcohols, ketones);
• element and organic compounds (phosphorodorganic, chloroorganic);
• inorganic (lead, mercury).

By aggregative state Harmful substances are divided into gases, pairs, aerosols and mixtures thereof.

According to the human body Harmful substances are divided into the following groups:

1. Toxic - The interaction with the human body, causing various deviations in the health state of the working. Depending on the physiological impact on a person, toxic substances can be conditionally divided into four groups:

• annoying acting on the respiratory tract and mucous membrane of the eye: sulfur gas, chlorine, ammonia, fluoride and chloride hydrogen, formatdehyde, nitrogen oxides;
• suffocating - violating the process of absorption of oxygen with tissues: carbon oxide, chlorine, hydrogen sulfide, etc.;
• narcotic - nitrogen under pressure, trichloroethylene, benzyl, dichloetancitylene, acetone, phenol, carbon tetrachloride;
• somatic - Causeing violation of the activities of the body or its individual systems: lead, mercury, benzene, arsenic and its compounds, methyl alcohol;

2. Sensitizing - causing neuroendocrine disorders accompanied by nest baldness, skin depigmentation;

3. Carcinogenic - causing cancer cells;

4. Generative - gonadotropic (acting on the sexual sphere), Embryotropic (acting on embryos), Mutagenic(acting on heredity).

5. Allergens - Causeing various allergic reactions. By the degree of danger to the human body, all harmful substances are divided into 4 hazard classes (GOST 12.1.007-76): 1st class - extremely dangerous; 2nd class - highly hazardous; 3rd grade - moderately dangerous; The 4th grade is low hazard.

Chemical substances depending on their practical use Classified on:

• industrial poisons - organic solvents used in production (for example, dichloroethane), fuel (for example, propane, butane), dyes (for example, aniline), etc.;
• yadochimikats - used in the agriculture of pesticides and others;
• medicines;
• household chemicals are used in the form of food additives (for example, vinegar), sanitation, personal hygiene, cosmetics, etc.;
• biological vegetable and animals of the poisons, which are contained in plants, mushrooms, in animals and insects;
• poisoning substances (s) - Zarin, Hyprit, phosgene, etc.

Types of harmful substances by the nature of the impact on a person:

• generaloxic - Causes to poisoning the entire body or affecting individual systems: a central nervous system, hematopoietic organs, liver, kidneys (hydrocarbons, alcohols, aniline, hydrogen sulfide, blue acid and its salts, mercury salts, chlorinated hydrocarbons, carbon monoxide, etc.);
• annoying causing irritation of mucous membranes, respiratory tract, eyes, lungs, leather (organic nitrogenants, dimethylaminobenzene and other antibiotics, etc.);
• sensitizing - acting as allergens (formaldehyde, solvents, varnishes, etc.);
• mutagenic - leading to a violation of genetic code, change in hereditary information (lead, manganese, radioactive isotopes, etc.);
• carcinogenic - causing malignant tumors (chromium, nickel, asbestos, benz (a) IYEV, aromatic amines, etc.);
• affecting reproductive (core) function - Causeing congenital defects, deviations from the normal development of children affecting the normal development of the fetus (mercury, lead, styrene, radioactive isotopes, boric acid, etc.).

Hazard classes of harmful substances

In the human body, harmful chemicals can penetrate through the respiratory organs, the gastrointestinal tract, the skin. The main way of penetrating harmful substances into the body is respiratory organs.

The distribution of harmful substances in the body is subject to certain patterns. First, the distribution of the substance in the body is occurring, then the absorption capacity of the tissues begins to play the main role.

The harmful effect of chemicals on the human body is studied special science - toxicology.

Toxicology - This is a medical science that studies the properties of poisonous substances, the mechanism of their action on the living organism, the essence of the pathological process (poisoning) caused by them, methods of its treatment and warnings. The region of toxicology that studies the effect of chemicals per person in the conditions of production is called industrial toxicology.

Toxicity - This is the ability of substances to have a harmful effect on living organisms.

The main criterion (indicator) of the toxicity of the substance is the PDC (unit of measurement of the concentration is mg / m 3). The substance toxicity indicator determines its danger. By the degree of danger, harmful substances are divided into four classes (Table 1).

Table 1. Classes of danger of substances on the MPC in the air of the working area (according to GOST 12.1.007-76)

In addition to the indicator of the PDC, which defines the hazard class on the concentration of the substance in the air, other indicators are used.

Average deadly concentration in air LC 50 (mg / m 3) - the concentration of the substance that causes the death of 50% of animals with two or four-hour inhalation.

Average deadly dose when applied to leather LD 50 (mg / kg - milligram harmful to kg of animal mass) dose of a substance that causes the death of 50% of animals in one-time application to the skin.

Middle deadly dose for 50 (mg / kg) - dose of a substance that causes the death of 50% of animals in one-time introduction into the stomach.

In determining the specified average fatal concentrations and doses of testing, they are carried out on mice and rats.

At the specified indicators, the hazard class of the substance is determined by the following quantitative values \u200b\u200b(Table 2).