Hazardous factors of fire: accompanying and affecting people. International Student Scientific Bulletin Distribution of fire hazards

Uncontrolled fire is a cruel enemy. Therefore, the fight against it is equivalent to military action. To win a war you need to know as much as possible about your enemies. The level of threat in military battles is assessed by the presence of hazard factors, which in the war with fire are called fire hazards.

What are fire hazards (FHFs)? The word factor itself denotes the cause, force, source of a process that determines its character or certain features, the direction of development. From this point of view, fire factors are indicators, phenomena that contribute to the development of a fire. What are the fire hazards? This is what leads to loss of health, disability, death of people and animals, damage, loss of property, and environmental pollution.

The following main fire factors have been identified:

• flame;
• sparks;
• smoke and reduced visibility;
• heat;
• combustion products;
• decreased oxygen;
• explosions;
• smoke toxicity;
• high voltage.

Which of the following are dangerous factors? Basic fire law in Russia or " Technical regulations about the requirements fire safety» divides fire indicators into

1. Fire hazards affecting people and property:

• heat flow;
• sparks, flame;
• high air temperature;
• decreased oxygen concentration;
• saturation of air with toxic combustion products;
• reduced visibility.

2. accompanying phenomena of general physical fitness:

• explosions and their consequences;
• individual structures, parts, fragments of destroyed buildings and structures;
• destruction of technological production equipment and environmental pollution with toxic, radioactive substances;
• exposure to substances used to extinguish fire.

Limits

The question often arises: what is not a fire hazard? From point of view common sense Everything in a fire is a danger. More precisely, these same indicators are called harmful until their value reaches the limit value. Harmful factors are those that pose a risk to health, but do not have a detrimental effect. They reduce performance and irritate human organs.

The limiting physical fitness indicators are defined as follows:

Oxygen concentration in the air

The air we breathe is not simple substance. It is a mixture of gases:

1. Nitrogen – 78% of volume.
2. Oxygen – 20% volume.
3. Carbon dioxide – 0.0314%.
4. Other substances: argon, neon, krypton, methane, helium, hydrogen, xenon - less than 1% in total.

The most valuable part of air is oxygen. It enters the human body through the respiratory system. Once in cells, it participates in the process of oxidation (burning nutrients), resulting in the release of energy necessary for other life processes.

Combustion is a chemical oxidation process in which a flammable material reacts with oxygen. As a result of the reaction, heat is released and liquid, solid, and gaseous combustion products are formed. The proportion of people who die from low oxygen levels among all causes of death is approximately 3-4%.

Concentration of toxic substances in the air

The most common toxic substances in fires are:

• Carbon monoxide (CO), also known as carbon monoxide, carbon monoxide. Characteristics: colorless and odorless gas. Flammable It is felt only in the presence of impurities. Chemical activity increases at high ambient temperatures.
• Carbon dioxide (CO 2) or carbon dioxide, carbon dioxide. Characteristics: colorless gas, almost odorless. Not flammable.

The human body's reaction to changes in the air:

CO		CO 2
Concentration in air, %		Concentration in air, %	Human physiological reaction
0,01	No noticeable changes are observed within several hours of exposure.	0,04	Close to normal. Harmless.
0,05	No noticeable changes are observed within one hour of exposure.	Up to 2.5	No noticeable changes are observed.
0,1	Poisoning moderate severity: The appearance of nausea, headache, dizziness, dry cough, increased blood pressure, the appearance of hallucinations.	3	Breathing speeds up and becomes deeper.
		4	There is a rapid pulse, headache, tinnitus, mental agitation, and high blood pressure.
0,5	Severe poisoning: loss of consciousness after 2-3 breaths, the appearance of convulsions, death - less than 3 minutes.	8	The appearance of tachycardia, the skin becomes bluish in color. Breathing is shallow and rapid. Death.

The proportion of people killed by combustion products is 77-78%.

Smoke formation and reduced visibility

Some substances burn (oxidize) completely in a fire, others partially. Those that are not completely burned form complex chemical compounds: alcohols, aldehydes, ketones, acids and others. They can burn for a long time. The products of incomplete combustion create toxic, acrid smoke. Air saturated with flammable substances becomes explosive. The situation is complicated by the presence high temperatures, which accelerate chemical processes.

Liquid and solid particles of combustion products limit the passage sunlight. Their large concentration makes it impossible to evacuate people from burning buildings and premises. Limited visibility does not allow you to navigate in an unfamiliar place. This situation may be accompanied by panic. There is no direct threat to people's lives from reduced visibility, but during the chaotic movement of the crowd they may die or be injured. The proportion of people who died from mental factors is approximately 0.08%.

Sparks, flames, heat flow

Flame is an indispensable attribute of any fire. If you run a match over a rough surface, the head material heats up and begins to actively oxidize, producing heat and light. In essence, flames are hot gases participating in the combustion process. Their temperature is so high that it can affect and heat other substances, involving them in the process. Therefore, the flame is able to develop a large area.

The combustion temperature depends on the combustible material. It can reach 2000-3000 o C. Despite the fact that a person consists of 80% water, with prolonged contact with fire he burns completely. Short contact with flame causes body damage - burns. They can be superficial and deep. Based on the depth of impact, they are divided into degrees:

• I degree: superficial thermal burn of the upper stratum corneum of the skin, is redness, does not cause irreversible changes.
• II degree: damage to several layers of skin, manifestation - blisters with liquid inside. Heals without scars due to skin regeneration.
• III degree: damage to all layers of the skin including subcutaneous fat. Characterized by tissue necrosis and scab formation. Heals with scar formation.
• IV degree: necrosis, charring of skin, tendons, bones. Dead tissue is sloughed off and replaced with deep, rough scars.

A spark is a burning particle of a substance; it is not always dangerous. A spark fire occurs when certain indicators are present. Combustion from a small particle can occur upon contact with flammable materials, for example, liquids: gasoline, acetone, alcohol, kerosene, etc. It is even more dangerous if the spark enters a space saturated with vapors and gases. For example, a mixture of air and petroleum product vapor is explosive. It burns instantly, releases a large amount of hot gases, and creates a shock wave with destructive force.

Heat flow and high air temperature

During large fires, powerful heat flows are created near the fire front; up to 90% of all heat generated by combustion is located here. Its impact on humans depends on the intensity in kW/m2:

Of course, the air temperature near fires can reach 100-150 o C. The human body also experiences overheating - hyperthermia. Due to overheating, a person develops heat injuries characterized by disturbances nervous system, gastrointestinal, cardiovascular syndromes.

Protection from general physical fitness

How can you protect yourself from the above? hazardous factors fire? There are three areas of activity:

1. Fire prevention. In this case, all causes of combustion and ways to avoid fire must be provided for: the use of space-planning solutions, fire barriers. No fire - no physical accident, no danger to people's lives or their property.
2. Creation of a fire safety system: installation of devices fire alarm, alerts, smoke protection, fire extinguishing systems, screens and partitions to limit the fire area, protection from heat flows.
3. Use of special protective equipment for firefighters. Protective clothing consists of the following items:

Fires have always been the most frequent and terrible disaster. Domestic fires that occur in residential buildings have great danger, since there is a high risk of human casualties. Fire is capable of leaving a person without housing and property in a short time, destroying entire settlements.

During fires, the greatest importance is given to the study of the main dangerous fire factors that have a destructive effect on material values and buildings, and also lead to various injuries, damage and poisoning of humans. In addition, secondary ones can also have a negative impact on people who find themselves in the zone of the fire element.

Knowledge about them allows fire department specialists to draw up a clear work plan for the prevention and subsequent elimination of fires. This information gives citizens the opportunity to save their lives and their loved ones. Let's look at them in more detail.

Primary factors

In order to find out how they affect a person and how long it takes for their destructive effects to manifest, an assessment based on their permissible value is used. This is the upper limit at which no pathological changes in health or bodily harm within the space of.

Let's consider the main fire hazards affecting people and their property.

Streams of flame and sparks

When a fire occurs, a moving flame does not appear immediately. The fire should gain strength, and after 25-30 seconds. Dangerous streams of fire begin to affect the surrounding area. Such rays gain the greatest strength and intensity during combustion. technological equipment or installations. In order to get closer than 10 m to them, special protective clothing is required.

The higher the intensity of the flame rays, the shorter the period of time during which a person can withstand them without severe consequences for his health. The critical criterion is an intensity of 3 thousand W/m. With it, no more than 15 seconds pass before the first painful sensations appear. The maximum time that the human body can withstand is 40 seconds.

During a fire, the air heats up quickly and can reach over 100 °C. At the same time, the most important organs are the most sensitive to high temperature: receptors (eyes, skin, nose) and respiratory tract (nasopharynx, lungs, bronchi, oral cavity). Their damage can lead to tragic consequences.

The air is heated not only in the part of the room where the fire is raging, but also in the neighboring rooms. The acceptable temperature criterion for human skin, at which no damage or pain occurs, is 45 °C.

If the temperature reaches 60–70 °C, then even short-term exposure causes burns to the mucous membranes and skin. Moreover, the maximum time during which the human body is able to withstand such external conditions is just over an hour. When the air temperature rises to 95–120 °C, the exposure time is no more than 20 minutes. In a situation where the air in a room is heated to 150 °C or higher, a person instantly receives a severe burn to the respiratory system. This leads to his death.

Accumulation of toxins and combustion products

When various objects burn, they are released as a result of their thermal decomposition toxic substances. Their high concentration in the surrounding space can have a toxic effect. In addition, in living quarters there are things that can smolder for a long time. This contributes to the emergence large quantity carbon monoxide. Common reasons The death of people in short-term fires is precisely poisoning from smoke and toxic substances. You should know that when the gas concentration in space reaches 0.32%, a person is already capable of losing consciousness, and after half an hour death occurs. If CO reaches 1.2% or more in the air, then a person dies within 3 minutes.

Reduced oxygen levels

During a fire, even if the concentration of combustion products is minimal, the lack of oxygen can negatively affect people’s well-being. At the very beginning of a fire, the O2 content drops by 15%. Disorders in the body begin when the 17% mark is reached. A person's coordination of movements is impaired and attention is reduced. Thinking becomes sluggish. Often, oxygen “starvation” slows down the evacuation process. People may behave inappropriately and, if necessary, will not be able to act quickly.

Smoke screen

Fire hazards also include reduced visibility due to the caustic smoke generated. Due to loss of visibility, people cannot find emergency exits. It becomes impossible to navigate the fire zone. In addition, the presence of particles of smoldering objects in the smoke corrodes the eyes and mucous membranes. The maximum value for smoke concentration and visibility in such conditions is 20 m.

The main fire factors discussed above have the greatest negative impact on people. In almost 90% of cases they are the cause of death in domestic fires.

Secondary factors

They have an indirect effect and arise as a consequence of the main factors. However, they can cause no less harm to a living organism.

These include:

1. Various components, debris and fragments of burnt installations, equipment and structures. Buildings destroyed by fire that could collapse at any moment.
2. An explosion accompanied by a shock wave. This creates enormous pressure. Parts of buildings, structures and structures flying over long distances are dangerous.
3. Radioactive and chemical contamination of nature as a result of toxic substances entering the atmosphere during fires in factories, warehouses and hazardous technical installations.
4. Melting of conductive cables under the influence of high temperature. This results in electrical shock.
5. Poisonous effects of fire extinguishing agents on the human body.

According to some data, secondary dangerous factors of fire include the occurrence of panic, i.e. psychological criterion. The inability of people to control their emotional state during emergencies makes the work of rescue services more difficult. People, caught in a fire trap, begin to perform chaotic actions or fall into a stupor. The crowd at the exit leads to numerous casualties as a result of the crush, and not the impact of fire factors. To avoid such situations, practical training should be conducted in enterprises and schools on what to do in case of fire.

The cause of fear, and as a consequence of the panic behavior of people during fires, is a lack of knowledge. It is important to carry out preventive and informational work with the population by relevant specialists: rescuers, firefighters and doctors.

The study of fire hazards helps improve warning systems, develop effective escape routes, and identify the real limits of fire resistance of various materials.

Open fire, high temperature, smoke and lack of oxygen are the main damaging fire factors.

During the burning of buildings and objects, the air heats up to 800–1500 °C, exceeding the maximum permissible temperatures for living organisms. Even short-term exposure to high temperatures (60–70 °C) can cause burns to the skin, eyes and respiratory tract. Survival is possible if second- and third-degree burns affect less than 20% of the person's body surface. Rehabilitation of such victims is complicated by constant pain, severe intoxication, nausea and vomiting. With a weakened immune system, infection and blood poisoning may occur.

High temperature can become either a direct cause of death or cause depression of the body’s defenses and the occurrence of conditions that aggravate the effects of other damaging fire factors(for example, combustion products).

At a temperature of 35–40 °C, additional stress is created on the cardiovascular, respiratory, endocrine and other functional systems of the body.

Fire hazards- open fire and high temperature - kill approximately 10% of victims.

Smoke and toxic combustion products (carbon monoxide, aldehydes, phosgene) cause severe poisoning. By inhaling carbon monoxide, which is invisible and odorless, a person dies within a few minutes from oxygen starvation. In addition, smoke is associated with panic, loss of orientation in space, difficulty or impossibility of evacuation. In this regard, smoke is a greater danger than the fire itself - 80% of people in a fire die from poisoning by combustion products.

Even in the absence of toxic gases, the lack of oxygen in the inhaled air causes a lack of attention and deterioration of motor functions. Human death occurs when the oxygen concentration drops to 11–16%, and during fires in residential premises this figure reaches 7–9%. Primary fire factors take up to 90% of lives.

Secondary fire factors

But not only fire and smoke lead to death. Falling buildings, release of toxic substances from mechanisms and assemblies, electric current and panic are related to secondary fire factors.

Exposure of flammable materials to high temperatures leads to fire growth. Above a certain temperature, strength decreases building structures, walls and ceilings collapse. Falling parts of a building lead to injury and death and make evacuation difficult.

When electrical wires are damaged, death due to electric current usually occurs due to cardiac or respiratory arrest. In this case, there may be no direct contact with current-carrying parts, but a stream of foam or water will act as a conductor, causing the death of a person.

Human factor of fire

Panic and unpreparedness for precise, collected actions during a fire are the main enemy during evacuation.

It can manifest itself both in inhibition, dulling of consciousness, and vice versa - in chaotic activity. In an effort to leave the fire site as quickly as possible, frightened people accumulate at the exit, block it, and crush each other. Such a state of panic emergency can kill even in the absence of a real threat.

From this information it becomes clear that the real threat is to modern humanity, making a negative contribution to the deterioration of living conditions.

An explosion, which is possible when a fire occurs near explosive substances, destroys parts of the structure, causing damage to people that is often incompatible with life.

Shock wave is one of the main damaging factors of the explosion. Destroying buildings and structures, it causes damage to all living beings at significant distances from the explosion site. Light radiation released during an explosion causes charring and ignition. The damaging energy of fragments depends on their mass and speed of movement from the center of the explosion.

For the purpose of fire prevention, forecasting is carried out fire hazards. It allows you to develop recommendations for safe evacuation, evaluate actual fire resistance limits, and create improved alarm and fire extinguishing systems. Forecasting methods fire hazards relate not only to the ability to foresee future events, but also to restore past ones. The need to reproduce the picture of a past fire is important, for example, when conducting forensic or fire-technical examination.

Any fire is accompanied by the manifestation of dangerous fire factors. Fire Hazardous Factor (FHF)- fire factor, the impact of which leads to injury, poisoning or death of a person, as well as material damage.

Hazardous fire factors (HFP) affecting people and material assets are:

• 1) flames and sparks;
• 2) increased ambient temperature;
• 3) toxic products of combustion and thermal decomposition;
• 4) reduced visibility in smoke;
• 5) reduced oxygen concentration.

TO secondary manifestations of dangerous fire factors relate:

• 1) fragments, parts of destroyed apparatus, units, installations, structures;
• 2) radioactive and toxic substances and materials from destroyed devices and installations;
• 3) electric current resulting from the transfer of high voltage to conductive parts of structures, devices, and units;
• 4) dangerous factors of an explosion that occurred as a result of a fire;
• 5) exposure to fire extinguishing agents.

About 73% of those killed in fires die from exposure to toxic combustion products, about 20% from high temperatures, and about 5% from low oxygen levels. The rest die from injuries received as a result of the collapse of building structures, the scattering of fragments during an explosion, due to the exacerbation and manifestation of hidden diseases and mental factors.

During fires, as a rule, there is a combined effect of several general physical properties at once. It is assumed that the total damaging effect from such an impact will be greater than from a simple summation of the effects of individual components. This phenomenon, when the result of an interaction is not a simple sum of particular actions, but generates qualitatively new results depending on the entire set of interactions, is called synergy. However, there is no reliable data yet to confirm or refute this assumption.

The fundamental document containing fire safety requirements is the federal law dated July 22, 2008 No. 123-FZ “Technical regulations on fire safety requirements.” This document regulates the requirements for fire prevention measures.

In accordance with this document, facilities must have fire safety systems aimed at preventing people from being exposed to fire hazards, including their secondary manifestations, at the required level. When determining the required level of fire safety for people, it is accepted that the probability of preventing exposure to hazardous factors per year per person must be at least 0.999999, and the permissible level fire danger for people - no more than 10 ~ 6 exposure to dangerous fire factors exceeding the maximum permissible values ​​per year per person.

Table 4.3 shows the limit values ​​of fire hazards.

Limit values ​​of fire hazards

Table 4.3

Control questions, tasks and tasks

• 1. Formulate a definition of fire. What conditions are necessary for combustion to occur?
• 2. Give brief description forms of combustion: flash, ignition, spontaneous combustion, spontaneous ignition, explosion.
• 3. Formulate the concept of upper and lower ignition limits (flame spread).
• 4. What is flash point? Ignition temperature?
• 5. What liquids are classified as flammable liquids (flammable liquids)?
• 6. What liquids are flammable liquids (FL)?
• 7. By what criterion is dust divided into explosive and fire hazardous?
• 8. Problem
• 1) Under the conditions of the example considered, determine the possibility of the formation of an explosive mixture when 2 liters of acetone are spilled.
• 2) Determine the explosive limits of a mixture of gases of the following composition:

Instruction: use Le Chatelier formula (4.1).

• 9. What zones are conventionally identified when modeling the consequences of an explosion?
• 10. How to determine the degree of destruction of buildings and structures under the influence of a shock wave?
• 11. How does the degree of damage to people depend on the value overpressure in the front of the shock wave?
• 12. List the main causes of explosions in production.
• 13. What is a fire hazard?
• 14. List the dangerous factors of fire.
• 15. What are the secondary manifestations of fire hazards?
• 16. What is equal to acceptable risk the impact of fire hazards on humans?
• 17. Problem. Assess the consequences of an explosion of acetylene cylinders if the amount of acetylene is 0.31 t and the distance to the workshop building is 65 m. TNT equivalence coefficient &eq = 3.82. Strength characteristics of the workshop:
• 1) weak destruction 10-20 kPa;
• 2) average destruction 20-30 kPa;
• 3) severe destruction 30-50 kPa;
• 4) complete destruction of more than 50 kPa.

Uncontrolled burning, which causes material damage, can harm the health and life of people, and the interests of the entire society, is called a fire. It can occur under three conditions. There must be a source of ignition:

• electric current, fire or chemical reaction;
• flammable materials, substances;
• the presence of an oxidizing agent, the role of which is well performed by oxygen.

Main damaging factors

The list of things that can cause destruction and loss of life has been determined at the federal level. Thus, the damaging factors of fire include:

• high temperatures;
• heat flow;
• sparks and flames;
• toxic products arising from combustion and thermal decomposition of many substances;
• reduced oxygen concentration.

Also, do not forget that problems are caused by reduced visibility in the smoke, confusion and panic of people.

The primary damaging factors of a fire are those phenomena that in most cases lead to material damage, injury, poisoning or even death. The destructive force is primarily fire, heat flow and combustion products released into the air.

Associated phenomena

Unfortunately, it is not only the main damaging factors of a fire that can cause problems. The accompanying phenomena also have destructive power. These include:

• removal of high voltage to those parts of equipment, technological installations, units that conduct current;
• possibility of explosion as a result of fire;
• getting into environment radioactive and toxic materials and substances.

The danger comes from parts and fragments of damaged buildings, structures, Vehicle, equipment and other property.

Possible problems

There are approximate statistics on which damaging fire factors are the most dangerous. Thus, almost ¾ of all those killed in a fire die from exposure to combustion products, which are toxic. According to rough estimates, about 73% of people die in fires for this reason. The cause of death for 20% of people is attributed to exposure to high temperatures. Another 5% of people die due to lack of oxygen. Only a small number of people die from secondary factors. Thus, only about 2% die from fragments carried by explosions or structural collapses.

All damaging factors of fire and explosion, even if they did not lead to the death of people, have an impact on them negative impact. They also destroy material values, the technogenic and natural environment.

Features of fires in enclosed spaces

Fire is one of the main sources of problems. It is he who leads to all the destruction. In enclosed spaces, a special combustion phase is possible, which experts call a “flash.” It occurs when a fire moves from initial stage into a developed one. However, it is possible only in those rooms where there is sufficient gas exchange.

There are two types of flares. This may be called "full coverage" or "reverse bounce". The first situation occurs when the room warms up and various surfaces ignite simultaneously. But the second type of outbreak occurs with a sudden sharp influx of fresh air. This can happen when doors or windows are opened.

Fires in enterprises

Responsibility for all consequences of fires in organizations lies with managers. The level of potential damage and human health depend on the level of training of management and employees.

To minimize the damaging factors of fire, organizations must develop a special action plan. Thus, company employees must report a fire to fire service and the head of the company. Before rescuers arrive, it is important to evacuate people and begin extinguishing fires. You must also turn off all equipment.

If a fire started in electrical installations that cannot be turned off instantly, you can only use special carbon dioxide fire extinguishers or sand. The use of water in such cases is prohibited.

If there are victims, it is the manager who is responsible for organizing the first medical care, delivering them to hospitals.

Danger level

All fire hazards are assessed taking into account the impact they can have on people’s health and lives. Thus, problems are caused by the main damaging factors of fire. Experts have established limit values ​​for each of them.

Thus, problems arise in cases where the temperature of the environment in Celsius exceeds 70 o, while thermal radiation should be more than 500 W/m2. The content of various substances in the air is also assessed. The situation becomes critically dangerous when the oxygen content in it becomes less than 17%, and the level of carbon dioxide (so-called carbon monoxide) reaches 6%.

Thus, when extinguishing fires at an ambient temperature of more than +70 o C, the safe time during which you can stay there is from 5 to 10 minutes, depending on the humidity level. You can stay in the place of fire at this temperature for no more than 20-35 minutes - these are the maximum permissible values. It is necessary to take into account that the first time period is indicated for a humidity level of 20%, and the second - 75%.

Possible problems

Each of the damaging factors is quite dangerous. But the worst thing is when they act all together. Thus, there are several degrees of burns, depending on the degree of heat flow.

The first stage is characterized by redness of the skin, the second - the appearance of blisters and possible disability. In the third degree, certain areas of the skin die. The fourth is characterized by the death of layers of skin and deep tissues. Two second degree burns can cause death.

Also damaging factors of a fire are the following: smoke, cloudy air, carbon monoxide, toxic fumes. All this ultimately becomes one of the main causes of death - poisoning and suffocation. Heatstroke also leads to death. If the air warms up to 70 o Celsius, then burns of the larynx and lungs are possible.

If a fire starts in a closed room, people often start to panic. This leads to rash actions that cause death. So, the most common of them are crushing in narrow rooms (for example, corridors) or jumping out of the windows of multi-story buildings and premises.

Secondary fire factors also lead to injuries, burns and death. People die under collapsed building structures or in cavernous floors.

Speed ​​of fire spread

It is important to understand that the extent of the problems will depend on how quickly the fire spreads. This is influenced by both the ambient temperature and the types of materials in the room. Some of them can spontaneously ignite. True, this becomes possible provided that a certain temperature level is reached in the room.

As it grows, the speed of fire spread increases. Also interesting is the fact that fire moves up vertical surfaces 8-10 times faster than the average values ​​of its spread.

If the temperature in the room reaches 100 o C, then the glass in the windows begins to collapse. And this leads to an additional influx of oxygen and the occurrence of the so-called “rebound”. In addition, the flame begins to spread to neighboring buildings and premises. This occurs due to the transfer of burning elements or thermal radiation.

The damaging factors of fire cannot be underestimated. After all, danger to people arises within 0.5-6 minutes after it starts. This is one of the main reasons why the evacuation of people from premises must begin immediately. It is also important to immediately begin extinguishing fires.

Fire in open areas

Many people mistakenly believe that only indoor fires are the most dangerous. But it is not always the case. A fire in a building can be contained without allowing it to spread. Fires in open areas, for example, in fields or forests, or on peat bogs, are much more dangerous. Dry leaves, branches in forests, ears of corn in fields burn well.

Heat flow and open fire are the main damaging factors forest fire. But don’t forget about oxygen burnout and smoke. During dry weather, which is often observed in the second part of summer, fires can cover vast areas. They can damage not only forests and agricultural lands, but also nearby small settlements. They burn out a layer of humus from the soil, destroy vegetation, and drive animals out of the forests. Also, as a result of the impact of fire, power and communication lines are disabled, crossings, bridges, and pipelines can be destroyed.

Therefore, it is so important that fire extinguishing actions are taken in a timely manner.

Actions of people

Once in the zone of fire spread, it is important to remember that the damaging factors of a fire include not only thermal radiation, but also an increase in the concentration of carbon dioxide. To avoid poisoning due to inhalation of fumes, it is necessary to use protective equipment. The simplest is an ordinary scarf or a small piece of cloth dipped in water. They need to protect their nose and mouth.

To get out of the problem area, you need to move against the wind, parallel to the spread of the fire. It is advisable to go to the nearest body of water - it could be a stream, lake or river. Once in a safe place, you must report the fire to a special service or forestry department.

To assess the extent of the problems, you need to know that on the plains the fire spreads at a speed of about 0.5-1.5 km/h. But in the forests the situation is much worse. Crown fires typically spread at a speed of 8-25 km/h. But there are situations when they can cover new territories much faster. Cases have been recorded when their speed reached 100 km/hour. Peat fires spread very slowly, usually 2-10 meters per day. But the difficulty is that they are difficult to extinguish.