The greatest danger is posed by fire-explosive objects of the categories. Explosive objects

Parameter name	Meaning
Article topic:
Rubric (thematic category)	Occupational Safety and Health

Transport accidents and their consequences.

Fire and explosive objects, fire extinguishing.

Topic No. 2. Forecasting and assessing the situation in emergency situations.

Section 3. Protection of the population and territories in emergency situations.

Questions:

Main literature:

1. Belov S.V. and etc.
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Life safety. - M.: Higher School, 1999, 447 p. – p.375-394

2. Rusak O.N., Malayan K.R., Zanko N.G. Life safety.-St. Petersburg: Publishing house Lan, 2002.-447 pp., pp. 393-397.

3. Grinin A.S., Novikov V.N. Environmental Safety. – M.: FAIR-PRESS, 2002, 336 pp. - pp. 58-161.

4.Kirillov G.N. Safety and protection of the population in emergency situations. – M.: Publishing house NC ENAS, 2001, 259 p. - With. 83-147.

Additional:

1. Arustamov E.A. Life safety/textbook.-M.: Publishing house. House ʼʼDashkov and Kʼʼ, 2001.-678с, pp.377-423.

2. Khvalyuskin S.I. Civil defense of water transport facilities. – M.: Transport, 1990, 123s, pp.122-147.

They call it a fire uncontrolled combustion causing material damage, harm to the life and health of people, and the interests of society and the state.

The essence of combustion was discovered in 1756. Russian scientist M.V. Lomonosov. He proved that combustion is a chemical reaction of combining a flammable substance with oxygen in the air.

Based on this, for combustion it is extremely important to have:

1. Flammable substance.

2. Oxidizing agent.

3. Ignition source.

Consequently, a fire can be stopped if at least one of the listed components is excluded from the combustion zone.

Fire and Explosion Hazardous Objects (PHOO)– enterprises that produce, store, transport explosive products or products that, under certain conditions, acquire the ability to ignite or explode.

These primarily include industries that use explosive and highly flammable substances, as well as railway and pipeline transport, which bears the main load when delivering liquid, gaseous, fire and explosive goods.

The fire and explosion hazard of objects is determined fire hazard parameters and the amount of materials used in technological processes, design features and operating modes of equipment, the presence of ignition sources and conditions for the rapid spread of fire.

Fire spread and their transformation into continuous fires depends on the density of buildings, destruction and other factors.

According to explosion, explosion and fire hazard, all air defenses are divided into five categories: A, B, C, D, D. Objects belonging to categories A, B, C are especially dangerous.

The occurrence of fires primarily depends on degree of fire resistance buildings and structures, which is divided into five basic groups:

Fire resistance levels 1 and 2 – the main structures of such structures are made of fireproof materials.

3 degrees of fire resistance – buildings with stone walls and wooden plastered floors.

4 degrees of fire resistance – wooden plastered houses.

Fire resistance level 5 – wooden buildings.

Wherein the degree of fire resistance of buildings and structures is determined minimum fire resistance limits of building structures and the flammability of the materials from which they are composed, and the fire resistance time.

The fire resistance limit of a structure is determined by the time in hours during which no through cracks appear, the structure itself does not lose its load-bearing capacity, does not collapse and does not heat up to a temperature above 200° on the side opposite to the fire.

All building materials, and therefore structures made from them, are divided into three groups:

1. Fireproof- ϶ᴛᴏ such materials that, under the influence of fire or high temperature, do not ignite, do not smolder or char (stone, reinforced concrete, metal).

2. Difficult to burn– which, when exposed to fire or high temperature, are difficult to ignite, smolder or char and continue to burn and smolder in the presence of a fire source (Clay-straw mixtures, asphalt concrete).

3. Combustible- ϶ᴛᴏ such materials that, under the influence of fire or high temperature, ignite or smolder and continue to burn and smolder after the source of fire is removed (wood, cardboard).

For example, wood begins to smolder at a temperature of 300°, and spontaneously ignites at T = 400°. Explosive destruction of concrete occurs at T=700-900°. Steel structures at T=650° lose their load-bearing capacity, and at T=1400-1500° they melt.

Accidents at air defense facilities associated with severe explosions and fires can lead to severe social and economic consequences. They are mainly caused by explosions of containers and pipelines with flammable and explosive liquids and gases, short circuits in electrical wiring, explosions and fires of certain substances and materials.

Fires during industrial accidents cause the destruction of structures due to combustion or deformation of their elements from high temperatures.

The most dangerous fires in administrative buildings. As a rule, interior walls are lined with panels made of combustible material. The ceiling tiles are also made from combustible wood boards. In many cases, fires are caused by the poor fire resistance of wood and other building materials, especially plastics.

Example- a terrible fire on February 10, 1999 at 6 pm in Samara in the police department building a few minutes before the end of the working day (on the 2nd floor of a five-story building). In an old building with wooden floors and numerous voids, 2 floors were engulfed in fire within 20 minutes. An hour later the entire building was on fire.

All fire departments of the city - 45 vehicles - were brought to the scene of the fire. The police officers left the building as best they could, many jumped out of the windows and most fell to their death.

The scale of the tragedy is shocking - 189 were injured, 57 died.

Foam rubber used in the manufacture of furniture is extremely dangerous in terms of fire; when burned, it emits toxic smoke containing cyanide compounds.

In conditions of cramped production, substances considered non-flammable become dangerous. Thus, wood, coal, peat, aluminum, flour, grain and sugar dust, as well as dust from cotton, flax, hemp, and jute, explode and burn. Common chemicals such as turpentine, camphor, barium, pyramidon and many others spontaneously combust.

Accidents at oil and gas production facilities always bring great disasters.

Fires caused by fuel combustion during transportation are not uncommon. During fires on railway transport, as a rule, wires break, which paralyzes all traffic.

Fire and explosion hazards are characterized by the following factors:

1. An air shock wave that occurs during various types of explosions of gas-air mixtures, tanks with superheated liquid and pressure tanks.

2. Thermal radiation from fires and flying fragments.

3. The action of toxic substances that were used in the technological process or formed during a fire or other emergency situations.

People in the burning zone suffer the most:

From open fire and sparks;

Increased ambient temperature;

Toxic combustion products;

Reduced oxygen concentration;

Falling parts of building structures, units and installations.

It must be remembered that accidents at air defense facilities go through five characteristic phases in their development:

1. Accumulation of deviations from the normal process.

2. Initiation of an accident.

3. Development of an accident, during which there is an impact on people, the natural environment and objects of the national economy.

4. Carrying out rescue and other emergency operations, localizing the accident.

5. Restoration of life after liquidation of the consequences of the accident.

Causes of fires:

1. In residential and public buildings:

Malfunction of the electrical network and electrical appliances;

Gas leaks;

Fires of electrical appliances left energized unattended;

Careless handling and pranks of children with fire;

Use of faulty or homemade heating devices;

Doors of furnaces and furnaces left open;

Release of burning ash near buildings;

Carelessness and negligence in handling fire.

2. At enterprises:

Violations committed during the design and construction of buildings and structures;

Failure to comply with basic fire safety measures by personnel and careless handling of fire;

Violation of fire safety rules of a technological nature during the operation of the enterprise (for example, during welding work), as well as during the operation of electrical equipment and electrical installations;

Use of faulty equipment in the production process.

The fire situation and the dynamics of its development depend on:

1. Ignition pulse.

2. Fire hazard of the facility.

3. Fire resistance of the structure and its elements.

4. Building density in the fire area.

5. Weather conditions, especially wind strength and direction.

The relative indicators of the number of fires in Russia to the number of the population are 3.5 times higher than similar indicators in developed countries, and our death rates as a result of fires are 4-9 times higher.

It must be remembered that the maximum temperature of inhaled air at which a person is still able to breathe for several minutes without special protective equipment is 116°.

The main parameter characterizing the damaging effect light radiation is a light pulse. It is measured in J/m² or kcal/cm² and determines the amount of light energy falling during the entire time of fiery glow on 1 m² of the illuminated surface . Taking into account the dependence on the magnitude of the light pulse, burns are distinguished:

1. 1st degree burns are caused by a light pulse equal to 2-4 kcal/cm² (84-168 J/m²). Redness of the skin is observed. Treatment is usually not required.

2. 2nd degree burns are caused by a light pulse equal to 5-8 kcal/cm² (210-336 J/m²). Blisters filled with a clear white liquid form on the skin.

3. 3rd degree burns are caused by a light pulse equal to 9-15 kcal/cm² (368-630 J/m²). Skin necrosis occurs with damage to the germ layer and the formation of ulcers. Long treatment is required.

4. 4th degree burns caused by a light pulse over 15 kcal/cm² (630 J/m²). Necrosis of the deeper layers of tissue (subcutaneous tissue, muscles, tendons, bones) occurs.

The main fire extinguishing agent is water. It is cheap, cools the combustion area, and the steam generated by the evaporation of water dilutes the burning medium.

In this case, it is not advisable to extinguish with water flammable liquids, which can significantly increase the area of ​​the fire and cause contamination of water bodies. At the same time, it is dangerous to use water when extinguishing live equipment.

To extinguish fires, water fire extinguishing installations, fire trucks or water nozzles, as well as individual fire extinguishing equipment are used.

Personal fire extinguishing equipment:

1. Accessories (sand, water, blanket, blanket, etc.).

2. Service documents (fire extinguisher, axe, hook, bucket).

Fire extinguisher is a technical device designed to extinguish fires at the initial stage of their occurrence.

There are:

Foam fire extinguishers intended for extinguishing fires with fire extinguishing foams: chemical(OHP fire extinguishers) or air-mechanical(ORP fire extinguishers).

They are not used when extinguishing various substances and materials that burn without air access, and electrical installations under voltage.

To activate the OHP-10 fire extinguisher, it is extremely important:

1. Bring a fire extinguisher to the fire.

2. Raise the handle up and throw it all the way.

3. Turn the fire extinguisher upside down and shake.

The disadvantages of these fire extinguishers include a narrow temperature range of use (from +5° to +45°), high corrosiveness of the charge, the possibility of damage to the extinguishing object, and the extreme importance of annual recharging.

Carbon dioxide fire extinguishers (CO) are intended for extinguishing fires of various substances, the combustion of which cannot occur without access to air, fires on electrified railway and city transport, electrical installations under voltage of no more than 10,000 V. The fire extinguishing agent in them is liquefied carbon dioxide (carbon dioxide). Temperature conditions for storage and use from -40° to +50°.

Fire extinguishers are divided into manual (OU-2, OU-3, OU-5, OU-6, OU-8), mobile (OU-24, OU-80, OU-400) and stationary (OSU-5, OSU-511 ). The shutter of manual op-amps must be pistol or valve type.

For operating the op-amp it is extremely important:

1. Break the seal.

2. Pull the pin.

4. Press the lever.

Must be remembered, that you cannot hold the op-amp in a horizontal position or turn it head down, or touch the bell with bare parts of your body, because the temperature on its surface drops to minus 60-70°. At the same time, when extinguishing electrical installations that are under voltage, it is prohibited to bring the bell closer to them and the flame closer than 1 meter.

Powder fire extinguishers (OP) designed to eliminate fires of all classes (solid, liquid and gaseous substances, electrical installations under voltage up to 1000 V).

Powder fire extinguishers are used in cars, garages, warehouses, agricultural machinery, offices and banks, industrial facilities, clinics, schools, and private homes.

It is extremely important to activate a manual OP:

1. Pull the pin.

2. Press the button (lever).

4. Press the gun lever.

5. Extinguish the flame from a distance of no more than 5 meters.

When extinguishing the fire, shake it and hold it vertically in the working position, without turning it over.

Explosion - This is an event that occurs suddenly (rapidly, instantly) in which a short-term process of transformation of a substance occurs with the release of a large amount of energy in a limited volume.

The extent of the consequences of explosions depends on their power and the environment in which they occur. There are three explosion zones:

1. Action of a detonation wave. It is worth saying that it is characterized by an intense crushing effect, as a result of which structures are destroyed into separate fragments, scattering at high speeds from the center of the explosion.

2. Effect of explosion products. It involves complete destruction of buildings and structures under the influence of expanding explosion products. At the outer boundary of the zone, the resulting shock wave breaks away from the explosion products and moves independently. Having exhausted their energy, the products of the explosion, having expanded to a density corresponding to atmospheric pressure, no longer produce a destructive effect.

3. Action of air shock wave. Includes three subzones: severe destruction, moderate destruction and weak destruction. At the outer boundary of the zone, the shock wave degenerates into a sound wave, audible over considerable distances.

Causes of explosions:

At explosive enterprises– destruction and damage to production tanks, equipment and pipelines; deviation from the established technological regime (for example, excess pressure and temperature inside the equipment); lack of constant monitoring of the serviceability of equipment and equipment and the timely implementation of scheduled repairs.

In residential and public buildings– unreasonable behavior of people and especially children; gas explosion; Act of terrorism.

Large buildings, structures, and equipment with light load-bearing structures that rise significantly above the ground surface are subject to the greatest destruction by explosion products and shock waves.

Degree of destruction:

1. Complete– floors collapsed and all the main supporting structures were destroyed. Restoration is not possible. Mass death of all living things. Occupies 13% of the entire area of ​​the lesion. Continuous rubble forms on the streets. Continuous fires do not occur due to severe destruction, the flame breaking off by a shock wave, the scattering of ignited debris and their filling with soil.

2. Strong– there are significant deformations of supporting structures. Most of the ceilings and walls were destroyed. Occupies an area of ​​up to 10% of the lesion. The buildings were heavily damaged. There are local rubble and areas of continuous fires.

3. Average– it was not mainly load-bearing structures that were destroyed, but secondary structures (light walls, partitions, roofs, windows, doors). Possible cracks in external walls. The ceilings in the basement are not destroyed. In utility and energy networks, there is significant damage and deformation of elements that require elimination. Occupies up to 15% of the lesion. The buildings suffer moderate damage. There may be local rubble, areas of continuous fires.

4. Weak– part of the internal partitions and filling of door and window openings were destroyed. The equipment has significant deformations. In utility and energy networks, destruction and breakdown of structural elements are insignificant. Occupies up to 62% of the affected area. There may be isolated rubble and fires.

The products of the explosion and the resulting air shock wave are capable of cause various injuries to a person, incl. and fatal. In zones 1 and 2 There is a complete defeat of people associated with the rupture of the body into parts, its charring under the influence of expanding explosion products that have a high temperature. In zone 3 damage is caused by both direct and indirect effects of the shock wave.

When directly exposed to a shock wave leading cause of injury in humans is an instant increase in air pressure, which is perceived by a person as a sharp blow.
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In this case, damage to internal organs, rupture of blood vessels, eardrums, concussion, and various fractures are possible. At the same time, high-speed air pressure can throw a person over considerable distances.

Lesions that occur under the influence of a shock wave are divided into:

1. Lungs– mild contusion, temporary hearing loss, bruises and dislocations of the limbs.

2. Average– brain injuries with loss of consciousness, hearing damage, bleeding from the nose and ears, severe fractures and dislocations of the limbs.

3. Heavy– severe contusion of the entire body, damage to internal organs and the brain, severe fractures of the limbs, death is possible.

4. Extremely heavy– injuries usually resulting in death.

Explosives- ϶ᴛᴏ chemical compounds or mixtures capable of rapid chemical transformation with the formation of highly heated gases, which, due to expansion and enormous pressure, are capable of producing mechanical work.

Explosives can be divided into groups:

1. Initiating - have enormous sensitivity to external influences (impact, puncture, heating) and are used to detonate the main explosive charge.

2. Blasting - less sensitive to external influences and have increased power. Exploded as a result of detonation.

3. Propellant - ϶ᴛᴏ gunpowder, the main form of chemical transformation of which is combustion. Can be used for blasting operations.

Explosions are often caused by formation of fuel, steam or dust-air mixtures. Such explosions occur as a result of the destruction of gas containers, communications, units, pipelines or technological lines. The explosion of such a mixture occurs at a certain concentration of the substance in the air. For example, if 1 m³ of air contains 21 liters of propane, then an explosion is possible, if 95 liters - a fire.

A large number of accidents are associated with discharges of static electricity. One of the reasons for this is the electrification of liquids and solids during their transportation through pipelines, when the electric field strength can reach 30 kV/cm.

Strong explosions of a dust-air mixture are usually preceded by local bangs inside the equipment, during which the dust becomes suspended to form an explosive concentration.

Up to 90% of accidents are associated with the explosion of steam-gas mixtures, while up to 60% of such explosions occur in closed equipment and pipelines.

Under certain conditions, acetylene is capable of explosive decomposition in the absence of oxidizing agents. The energy released in this case is sufficient to heat the reaction products to T = 2800°.

High-pressure acetylene devices and pipelines are the most dangerous in operation, because in case of accidental overheating, an explosion may occur, which turns into detonation if the pipeline is long.

A mixture of acetylene with chlorine and other oxidizing agents may explode when exposed to a light source.

Often, when manually opening iron drums with calcium carbide, sparking occurs, which leads to explosions.

Fire and explosive objects, fire extinguishing. - concept and types. Classification and features of the category "Fire and explosive objects, fire extinguishing." 2017, 2018.

MAN-MADE EMERGENCIES

LECTURE 2 (4 hours) FIRES AND EXPLOSIONS.

Fire - This is an uncontrolled combustion process in a limited area, which can lead to the destruction or destruction of material assets, and creates a danger to the life and health of people.

Combustion - a chemical reaction of oxidation of flammable substances, proceeding relatively slowly (compared to an explosion), but with a large release of thermal energy.

Flammable These are substances and materials that continue to burn after the ignition source is removed.

Oxidizing agent most often it is air oxygen, but its role can be played by chlorine, fluorine, bromine, iodine, nitrogen oxides, etc. The combustion of most substances stops when the oxygen concentration in the air decreases from 21 to 14-18%.

Sources ignition can serve random sparks, heated bodies, open fire, arson.

Signs of a starting fire:

1- smell of smoke;

2- minor fire, flame;

3- presence of a characteristic smell of burning rubber or plastic;

4- decrease in voltage in the electrical network - signs of burning electrical wiring.

CAUSES OF FIRES:

· careless handling of fire;

· accidental or intentional arson;

· spontaneous combustion;

· loss of tightness of containers and equipment with flammable liquids (fuel, finished products, semi-finished products);

· faulty electrical wires;

· violation of the rules of work during welding production, non-compliance with operating rules;

· industrial explosion.

The extent of the fire depends on the heat impulse ( fi) J/m 2 min(the amount of heat generated per 1 square meter per minute).

1 - combustion zone

2 - constant burning zone (everything that can burn burns)

3 - zone of attenuation (burnout), when the flammable material burns and the fire dies out on its own without extinguishing.

Simmer effectively in 1 zone. The fire must be detected as early as possible:
1 minute - a glass of water; 2 minutes - a bucket of water;
3 minutes - 50 cc. fire pool.

In case of fires, people can get 3 degrees of burns from exposure to high temperatures:

· burn (redness, does not require special treatment, you can get it on the beach from the sun);

· burn - moderate severity, deeper damage to the skin, blisters form, very painful, hospitalization.

· burn - damage to the deeper layers of the skin, down to the bones, hospitalization.

The area of ​​the burn affects the condition of people; more than 30% is life-threatening.

The area of ​​the burn can be determined by comparing it with the area of ​​the palm; it is about 1% of the surface area of ​​the human body. Burns from burning clothing, which are difficult to extinguish and throw off, are very dangerous;

Fire Hazards:

1. Flame and sparks - lead to burns and damage to the respiratory tract. At a temperature of about 200C, human life lasts no more than 5 minutes.

2. Combustion gases . Excessive concentration CO in the air reduces the supply of oxygen and the consequence of this is rapid breathing. When the oxygen concentration is below 10%, loss of consciousness occurs. Carbon monoxide CO content of more than 1% leads to death within 3 - 5 minutes.

3. Toxic combustion products of polymer materials - styrene, formaldehyde, hydrogen cyanide, phenol lead to acute poisoning with a fatal outcome.

4. Smoke impairs visibility, causes irritation to the eyes and lungs.

5. Collapse of structures - leads to mechanical injuries.

Fires are divided into: domestic, industrial, natural

NATURE OF FIRES BY AREA OF SPREAD:

· individual fires (part of a building or one building is on fire);

· massive fires (2 or more buildings burn in a certain area up to 50%);

· continuous fires, such as when 50% of buildings and structures in a given area are on fire);

· fire storm (it is useless to extinguish, 100% of the territory burns out from the periphery to the center, for example, a nuclear explosion);

· landscape fires (the area is burning, a grain field is burning, crown forest fires, the spread speed is very high 100 m/h, peat fires - without flame - are difficult to extinguish).

Structural (passive) fire protection:

Fire prevention and fire protection measures are developed at the design stage of industrial activities. Issues of fire prevention, organizational and organizational-technical decisions, provision and maintenance of fire equipment are under the jurisdiction of fire-technical commissions of enterprises, fire protection services and departmental ones and are controlled by fire supervision authorities.

1. When designing a building, it is necessary to provide for ease of approach and penetration into the premises of fire departments, reducing the risk of fire spreading between floors, using fire walls, partitions, and ceilings in the building design; minimum fire resistance limits are established for each of these structures.

Fire resistance limit is the time during which a structure resists the effects of fire while maintaining operational functions.

2. Creating conditions for the safe evacuation of people - this is the equipment of emergency exits and fire escapes. Clear information about the location of emergency exits must be posted in buildings and an evacuation plan must be presented. Obstruction of passages and emergency exits is not allowed.

Active fire protection:

consists of creating a fire alarm (can be electric and automatic), installing automatic fire extinguishing systems, and supplying premises with primary fire extinguishing means.

The main fire extinguishing agents are water, chemical and air-mechanical foam.

Water – the most common means of extinguishing fires. Once in the combustion zone, it heats up and evaporates, absorbing a large amount of heat. During evaporation, a large amount of steam is formed (1 liter of water produces over 1700 liters of steam during evaporation), which prevents the access of oxygen to the burning substance.

You cannot use a jet of water to extinguish flammable and combustible liquids with a density less than one (gasoline, kerosene, acetone), because These substances are lighter than water, they float to its surface, continue to burn and, spreading, increase the combustion area.

foam (chemical and air-mechanical) is used to extinguish solids and flammable liquids with a density less than 1.

Chemical foam formed as a result of the reaction between an alkali and an acid in the presence of a foaming agent.

Air-mechanical foam – consists of gas bubbles surrounded by films of liquid. It is obtained by mixing water and a foaming agent while simultaneously mixing in air.

Hand-held fire extinguishers are an effective means of extinguishing small fires.

Chemical foam fire extinguishers (OCF) used when extinguishing flammable materials, with the exception of live electrical installations. Used at temperatures from +5 to +50C.

Carbon dioxide fire extinguishers (CO) are used to extinguish fires of various substances and materials at ambient temperatures from -25 to +50C, as well as live electrical equipment.

Powder fire extinguishers (OP used to extinguish fires of gasoline, diesel fuel, varnishes, paints and other flammable liquids at ambient temperatures from -25 to +50C, as well as electrical installations under voltage up to 1000V.

Devices - detectors There are manual and automatic. Manual in the form of buttons they are installed in corridors and on staircases. Automatic Fire detectors, depending on the response pulse, are divided into smoke, heat and light.

Smoke detector reacts to the appearance of smoke, thermal - to increase the air temperature in the room, and light - to radiation from an open flame.

The size of the fire depends :

1. on the degree of fire resistance of buildings and structures, there are 5 degrees of fire resistance (1 - non-combustible; 5 - flammable).

Fire resistance- this is the time in hours during which this structure does not lose its load-bearing capacity, does not crack, and does not heat up on the other side above 200C. Fire resistance ranges from several minutes to several hours. The fire resistance limit depends on the thickness, physical and chemical properties of the materials.

Fire resistance degree depends on the materials from which the building or structure is made. The following types of materials are distinguished:

· fireproof materials that do not burn, do not char and retain mechanical strength even in the presence of fire (reinforced concrete);

· difficult-to-burn materials that burn only in the presence of fire (sand-lime brick);

· easily - combustible materials that burn even when the heat source is removed (wooden structures).

Characteristics of accidents at fire and explosion hazardous objects Processes of combustion, detonation, explosion. Basics of fire prevention.

Accidents at fire and explosive objects

Fire and Explosion Hazardous Facilities (FHE) are enterprises where explosive products or products that acquire the ability to ignite or explode under certain conditions are produced, stored, and transported.

According to explosion, explosion and fire hazard, all air defense facilities are divided into 6 categories: A, B, C, D, D, E. Objects belonging to categories A, B, C are especially dangerous.

Fires at large industrial enterprises and in populated areas are divided into individual and massive:

q individual - fires in a building or structure;

q massive - this is a collection of individual fires, covering more than 25% of buildings. Fires and explosions most often occur in fire- and explosive-hazardous objects. These are enterprises that use explosives and flammable substances in the production process, as well as railway and pipeline transport used for transporting (pumping) fire and explosive substances.

Fire and explosion hazardous facilities include enterprises of the chemical, gas, oil refining, pulp and paper, food, paint and varnish industries, enterprises using gas and oil products as raw materials or energy carriers, all types of transport transporting explosive and fire hazardous substances, fuel filling stations, gas and product pipelines. Wood, coal, peat, aluminum, flour and sugar dust, for example, explode and burn. That is why fire and explosion hazardous facilities also include workshops for the preparation of coal dust, wood flour, powdered sugar, flour mills, sawmills and woodworking industries.

People in the fire zone are most affected by open flames, sparks, high temperatures, toxic combustion products, smoke, reduced oxygen concentrations and falling parts and structures.

Explosions not only lead to destruction and damage to buildings, structures, technological equipment, tanks, pipelines and vehicles, but also, as a result of the direct and indirect action of the shock wave, can cause various injuries to people, including fatal ones.

The fire safety rules of the Russian Federation oblige every citizen to immediately notify the fire department by telephone if they detect a fire or signs of burning (smoke, burning smell, increased temperature, etc.), and also take, if possible, measures to evacuate people and extinguish fire and safety of material assets. After notifying the fire department, you should try to extinguish the fire using available means (fire extinguishers, internal fire hydrants, blankets, sand, water, etc.).

If it is impossible to extinguish the fire, you must evacuate immediately. To do this, first of all use staircases. If they smoke, tightly close the doors leading to stairwells, corridors, halls, burning rooms, and go out onto the balcony. From there, evacuate via a fire escape or through another apartment, breaking the easily destructible partition of the loggia, or get out yourself through windows and balconies, using available means (ropes, sheets, luggage straps, etc.).

When rescuing victims from burning buildings, you should cover your head with a wet blanket before entering a burning room; open the door to a smoky room carefully to avoid a flash of flame from a rapid influx of fresh air; crawl or crouch in a heavily smoky room; to protect against carbon monoxide, use an insulating gas mask or, as a last resort, breathe through a moistened cloth; if the victim’s clothes caught fire, you need to throw some kind of blanket (coat, raincoat, etc.) over him and press tightly to stop the flow of air to the fire; Apply bandages to the burn areas and send the victim to the nearest medical center. It is dangerous to enter a smoke zone when visibility is less than 10m.

If there is a threat of explosion, you should first of all leave the dangerous place, warning others about the danger. Report the possibility of an explosion to the police. If an explosion is inevitable and escape is impossible, you need to lie down and cover your head with your hands.

Grieftion- a complex physical and chemical process of converting the components of a combustible mixture into combustion products with the release of thermal radiation, light and radiant energy. The nature of combustion can be roughly described as rapidly occurring oxidation. Subsonic combustion (deflagration), unlike explosion and detonation, occurs at low speeds and is not associated with the formation of a shock wave. Subsonic combustion includes normal laminar and turbulent flame propagation, while supersonic combustion includes detonation. Combustion is divided into thermal and chain. Thermal combustion is based on a chemical reaction that can proceed with progressive self-acceleration due to the accumulation of released heat. Chain combustion occurs in some gas-phase reactions at low pressures.

Detonation(normal) - a supersonic complex consisting of a shock wave and an exothermic chemical reaction behind it. Detonation (French detoner - to explode, from Latin detono - to thunder), a process of chemical transformation of an explosive substance, accompanied by the release of energy and propagating through the substance in the form of a wave from one layer to another at supersonic speed. The chemical reaction is introduced by an intense shock wave, forming the leading edge of the detonation wave. Due to the sharp increase in temperature and pressure behind the shock wave front, the chemical transformation proceeds extremely quickly in a very thin layer immediately adjacent to the wave front. The mechanism of energy conversion at the front of a detonation wave is significantly different from the mechanism of deflagration - a slow combustion wave accompanied by subsonic flows. Most often in everyday life, detonation occurs in car engines.

EXPLOSION- the process of extremely rapid release of a large amount of energy in a limited volume, which can lead to casualties, destruction, disasters, man-made accidents and other emergency situations.

The explosion generates blast waves in the environment. The processes responsible for the rapid release of energy are very diverse: Explosive detonation, thermal explosion, chemical and nuclear chain reactions, destruction of a stressed solid body and shells with compressed gas, vaporization in a superheated liquid, etc. Distinguish. a feature of these processes is the acceleration of energy release after Initiation. In this case, the expansion of the energy release region occurs at speeds that, as a rule, exceed the speed of sound in an undisturbed medium.

The mechanism of action of an explosion covers the processes of transfer and dissipation of explosion energy in the environment. The processes in shock waves are of greatest importance: heating, ionization and glow of gases, destruction and phase transitions in condenser. environments, irreversible changes in matter.

Human activity is aimed at obtaining energy, its accumulation and subsequent use. In this case, cases of uncontrolled energy release are possible, which can be realized in the form of explosions, fires and mechanical impacts.

Fire and Explosion Hazardous Objects (FEC)– facilities where explosive products or products are produced, stored, transported,
acquiring the ability to ignite or explode under certain conditions. These primarily include industries that use explosive and highly flammable combustible substances (oil depots and oil depots, ammunition depots, explosives depots (BB) etc.)

All air defense organizations are divided into categories:

	Name of production
(explosion and fire hazard)	Oil refineries, chemical plants, pipelines, petroleum product warehouses and etc. (most dangerous)
(explosion and fire hazard)	Shops for the preparation and transportation of coal dust, wood flour, powdered sugar, knockout and separate sections of mills, etc.
(fire hazardous)	Sawmills, woodworking, carpentry, lumberyards, etc. production
	Production processes involving combustion as fuel GG and flammable liquid
	Production, storage and use of non-combustible substances and materials in a hot, incandescent and (or) molten state, the processing of which is accompanied by the release of radiant heat, sparks and flames, as well as production associated with the combustion of solid, liquid and gaseous fuels (metallurgical production, boiler rooms, etc.)
	Production with non-flammable substances and materials cold

The most fire-hazardous enterprises include enterprises of categories: A, B, C. Enterprises G1-G2, D are classified as non-fire hazardous enterprises.

Law of the Republic of Belarus “On Industrial Safety of Hazardous Production Facilities”, dated January 10, 2000 No. 363-3, defined two categories hazardous production facilities (OPO) where the following hazardous substances are produced, used, processed, generated, stored and transported:

Fire and explosive objects (FHE) are objects where products are produced (stored, transported) that acquire the ability to ignite or explode under certain conditions (accident, initiation, etc.).

Based on explosion and fire hazards, air defenses are divided into five categories:

category B - workshops for the preparation and transportation of coal dust, wood flour, powdered sugar, knockout and grinding departments of mills with a flash point of more than 28 ° C, with a content of combustible dust and fibers in the air of 65 g/m3;

26. Forecasting the chemical situation during an accident (destruction) at a chemically hazardous facility

A chemically hazardous facility (CHF) is a facility where a hazardous chemical is stored, processed, used or transported, in the event of an accident or destruction of which, death or chemical contamination of the environment may occur. The destruction of a chemically hazardous facility is the result of catastrophes and natural disasters, which led to the complete depressurization of all containers and disruption of technological communications. An accident is a disruption of technological processes in production, damage to pipelines, tanks, storage facilities, vehicles, leading to the release of hazardous chemicals into the atmosphere in quantities that can cause mass casualties of people and animals. An emergency chemically hazardous substance (HAS) is a dangerous chemical substance used in industry and agriculture, in the event of an emergency release (spill) of which the environment can be contaminated in concentrations that can affect a living organism (toxodoses).

Forecasting and assessing the chemical situation includes solving the following problems: - determining the direction of the trace axis of a cloud of chemical substances released due to an accident or destruction of technological equipment or containers for storing hazardous chemicals, based on weather data; - determination of the size of areas of contamination of the area based on the expected values ​​of damage doses; - determination of the area affected by hazardous substances; - determination of the time of approach of contaminated air to the object and the duration of the damaging effect of hazardous chemicals; - determination of possible damage to people located in the source of infection; - the procedure for drawing affected areas on maps and diagrams.

27. Basic methods of protection against the toxic effects of hazardous chemicals.

Toxicity is the process of interaction of chemicals with organs and tissues of the human body with the formation of new chemical compounds that are not characteristic of it, leading to disruption of the functioning of individual organs, systems and the body as a whole.

The toxicity of substances depends on:

– the method of penetration of the substance into the body – the most dangerous is through the respiratory system and then into the blood.

– state of aggregation;

– solubility in water, blood, lymphatic fluid.

According to their functional effect on the body, toxic substances are divided into:

– nervous, causing a disorder of the central nervous system;

– blood, changing the composition of the blood;

– irritating, causing irritation of the upper and deep respiratory tract;

– mutagenic, affecting the genetic apparatus;

– carcinogenic, causing cancer;

– cauterizing, cause skin damage, the formation of ulcers and abscesses.

Basic measures to prevent the harmful effects of toxic substances:

– replacement of toxic substances used in technological processes with less toxic ones;

– the use of substances capable of dust formation in a paste or granular state;

– pneumatic transport of bulk substances;

– strict and precise compliance with technological regulations;

– sealing of process equipment;

– rational, space-planning solution for industrial buildings;

– rational placement of technological equipment;

– use of automatic and remote control of technological processes;

– time protection – limiting working hours when in contact with harmful substances;

– ventilation of premises;