A colorless, odorless gas slightly lighter than air. Characteristics of explosive and harmful gases. Natural gas is the best fuel type

16.08.2020

The most commonly found explosive and harmful gases in tanks and underground structures are methane, propane, butane, propylene, butylene, carbon monoxide, carbon dioxide, hydrogen sulfide and ammonia.

Methane CH 4(swamp gas) is a colorless, odorless, flammable gas, lighter than air. Penetrates into underground structures from the soil. It is formed during the slow decomposition of plant substances without access to air: during the rotting of fiber under water (in swamps, stagnant waters, ponds) or the decomposition of plant residues in coal deposits. Methane is a component of industrial gas and, if the gas pipeline is faulty, can penetrate into underground structures. Not poisonous, but its presence reduces the amount of oxygen in air environment underground structures, which leads to disruption of normal breathing when working in these structures. When the methane content in the air is 5-15% by volume, an explosive mixture is formed.

Propane C 3 H 8, butane C 4 H 10, propylene C 3 H 6 and butylene C 4 H 8- colorless flammable gases, heavier than air, odorless, difficult to mix with air. Inhaling propane and butane in small quantities does not cause poisoning; propylene and butylene have a narcotic effect.

Liquefied gases with air can form explosive mixtures at the following content, % by volume:

Propane 2.1-9.5

Butane 1.6-8.5

Propylene 2.2-9.7

Butylene 1.7-9.0

Protective equipment - hose gas masks PSh-1, PSh-2, self-rescuers SPI-20, PDU-3, etc.

Carbon monoxide CO- a colorless, odorless, flammable and explosive gas, slightly lighter than air. Carbon monoxide is extremely poisonous. The physiological effects of carbon monoxide on humans depend on its concentration in the air and the duration of inhalation.

Inhaling air containing carbon monoxide above the maximum permissible concentration can lead to poisoning and even death. When the air contains 12.5-75% by volume of carbon monoxide, an explosive mixture is formed.

Protective equipment - filtering gas mask of the CO brand, self-rescuers SPI-20, PDU-3, etc.

Carbon dioxide CO 2(carbon dioxide) is a colorless, odorless gas with a sour taste, heavier than air. Penetrates into underground structures from the soil. Formed as a result of decomposition organic matter. It is also formed in reservoirs (tanks, bunkers, etc.) in the presence of sulfonated coal or coal due to its slow oxidation.

Getting into an underground structure, carbon dioxide displaces the air, filling the space of the underground structure from the bottom. Carbon dioxide is not poisonous, but has a narcotic effect and can irritate mucous membranes. At high concentrations it causes suffocation due to a decrease in oxygen content in the air.

Protective equipment - hose gas masks PSh-1, PSh-2, self-rescuers SPI-20, PDU-3, etc.

Hydrogen sulfide H 2 S- a colorless flammable gas, has the smell of rotten eggs, and is somewhat heavier than air. Poisonous, affects nervous system irritates the respiratory tract and eyes.

Protective equipment - filtering gas masks of brands V, KD, self-rescuers SPI-20, PDU-3, etc.

Ammonia NH 3- a colorless flammable gas with a sharp characteristic odor, lighter than air, poisonous, irritating to the eyes and respiratory tract, causing suffocation. When the ammonia content in the air is 15-20% by volume, an explosive mixture is formed.

Protective equipment - filtering gas mask of the KD brand, self-rescuers SPI-20, PDU-3, etc.

Hydrogen H 2- a colorless, flammable gas without taste or odor, much lighter than air. Hydrogen is a physiologically inert gas, but at high concentrations it causes asphyxiation due to a decrease in oxygen content. When acid-containing reagents come into contact with the metal walls of containers that do not have an anti-corrosion coating, hydrogen is formed. When the hydrogen content in the air is 4-75% by volume, an explosive mixture is formed.

Oxygen O2- a colorless gas, odorless and tasteless, heavier than air. It has no toxic properties, but with prolonged inhalation of pure oxygen (with atmospheric pressure) death occurs due to the development of pleural pulmonary edema.

Oxygen is not flammable, but is the main gas that supports combustion of substances. Highly active, combines with most elements. Oxygen forms explosive mixtures with flammable gases.

1. Colorless gas, odorless. 2. Heavier than air, 3. Poisonous, 4. Highly soluble in water, 5. Poorly soluble in water, 6. Slightly lighter than air, 7. Exhibits acidic properties. 8. Non-salt-forming oxide. 9. Combines with blood hemoglobin, 10. Obtained from the decomposition of carbonates. 11. At high pressure it liquefies, forming “dry ice”, 12. Used to produce soda, 13. Used as gas fuel, 14. Used in the production of fruit waters, 15. Used in organic synthesis. 1. Colorless gas, odorless. 2. Heavier than air, 3. Poisonous, 4. Highly soluble in water, 5. Poorly soluble in water, 6. Slightly lighter than air, 7. Exhibits acidic properties. 8. Non-salt-forming oxide. 9. Combines with blood hemoglobin, 10. Obtained from the decomposition of carbonates. 11. At high pressure it liquefies, forming “dry ice”, 12. Used to produce soda, 13. Used as gas fuel, 14. Used in the production of fruit waters, 15. Used in organic synthesis.

Carbonic acid H 2 CO 3 Mr(H 2 CO 3) = =62 Carbonic acid H 2 CO 3 Mr(H 2 CO 3) = =62

Because carbonic acid dibasic, it forms two types of salts: carbonates and bicarbonates (Na 2 CO 3, NaHCO 3). Carbonates of alkali metals and ammonium are highly soluble in water, carbonates of alkaline earth metals and some others are practically insoluble in water. Carbonates of aluminum, iron, chromium cannot exist in aqueous solutions, as they undergo complete hydrolysis. Almost all hydrocarbonates are soluble in water. Since carbonic acid is dibasic, it forms two types of salts: carbonates and hydrocarbonates (Na 2 CO 3, NaHCO 3). Carbonates of alkali metals and ammonium are highly soluble in water, carbonates of alkaline earth metals and some others are practically insoluble in water. . Carbonates of aluminum, iron, and chromium cannot exist in aqueous solutions, as they undergo complete hydrolysis. Almost all bicarbonates are soluble in water

Na 2 CO 3 – Soda ash – used to produce alkalis, in glass production, and in everyday life as a detergent. NaHCO 3 - baking soda or drinking soda - is used in the food industry, for charging fire extinguishers, and in medicine for heartburn. (CuOH) 2 CO 3 – malachite – in pyrotechnics, for the production of mineral paints, in nature in the form of the mineral malachite (ornamental stone) CaCO 3 – chalk, limestone, marble – for the production of lime, marble as a finishing stone, in agriculture for liming soils. K 2 CO 3 – potash – for making soap, refractory glass, in photography. Na 2 CO 3 *10H 2 O - crystalline sodium carbonate - consumed by the soap, glass, textile, paper, and oil industries. Na 2 CO 3 – Soda ash – used to produce alkalis, in glass production, and in everyday life as a detergent. NaHCO 3 - baking soda or drinking soda - is used in the food industry, for charging fire extinguishers, and in medicine for heartburn. (CuOH) 2 CO 3 – malachite – in pyrotechnics, for the production of mineral paints, in nature in the form of the mineral malachite (ornamental stone) CaCO 3 – chalk, limestone, marble – for the production of lime, marble as a finishing stone, in agriculture for liming soil K 2 CO 3 – potash – for making soap, refractory glass, in photography. Na 2 CO 3 *10H 2 O - crystalline sodium carbonate - consumed by the soap, glass, textile, paper, and oil industries.

Poison gas is a toxic chemical substance that causes intoxication of the body and damage to internal organs and systems. Enters through the respiratory system, skin, and gastrointestinal tract.

List of poisonous gases depending on their toxicological effects:

Nerve agents – carbon monoxide, sarin.
Blisters – lewisite, mustard gas.
Asphyxiants - phosgene, diphosgene, chlorine.
Tear relievers – bromobenzyl cyanide, chloroacetophenone.
General exposure: hydrocyanic acid, cyanogen chloride.
Irritants – adamsite, CR, CS.
Psychotomimetic – BZ, LSD-25.

Let's consider the most dangerous gases, the mechanism of their destruction, and signs of poisoning in humans.

Sarin

Sarin is a toxic liquid substance that at a temperature of 20 °C it quickly evaporates and has a nerve-paralytic effect on the human body. As a gas, it is colorless and odorless and is most dangerous if inhaled.

Symptoms appear immediately upon exposure to the respiratory tract. The first signs of poisoning are difficulty breathing and constriction of the pupil.

Clinical manifestations:

irritation of the nasal mucosa, liquid discharge;
drooling, vomiting;
chest tightness;
shortness of breath, bluish skin;
spasm of the bronchi and increased formation of mucus in them;
pulmonary edema;
severe cramps and pain in the abdomen.

If high concentration sarin vapor enters the body severe brain damage occurs within 1-2 minutes. A person cannot control the physiological functions of the body - involuntary bowel movements and urination. Convulsions and seizures appear. Coma develops followed by cardiac arrest.

Mustard gas

Mustard gas is mustard gas. This is a chemical compound with blister action. In liquid form, the substance has a mustard smell. It enters the body in two ways - by airborne droplets and by contact of liquid with skin. It tends to accumulate. Signs of poisoning appear after 2-8 hours.

Symptoms of gas intoxication by inhalation:

damage to the mucous membrane of the eyes;
lacrimation, photophobia, feeling of sand in the eyes;
dryness and burning in the nose, then swelling of the nasopharynx with purulent discharge;
laryngitis, tracheitis;
bronchitis.

If the liquid gets into the eyes, it will cause blindness. In severe cases of mustard gas poisoning, pneumonia develops and death occurs on the 3-4th day from suffocation.

Symptoms of gas poisoning upon contact with the skin are redness followed by the formation of blisters containing serous fluid, skin lesions, ulcers, necrosis. The gas destroys cell membranes, disrupts carbohydrate metabolism, and partially destroys DNA and RNA.

Lewisite

Lewisite is a highly toxic substance, the vapors of which can penetrate chemical protective suits and gas masks. It is a brown liquid with a pungent odor. The gas is classified as a skin vesicant. Acts on the body instantly and has no latency period.

Symptoms of gas poisoning when the skin is affected develop within 5 minutes:

pain and burning at the point of contact;
inflammatory changes;
painful redness;
formation of bubbles, they quickly open;
the appearance of erosions, which take several weeks to heal;
in severe cases, when exposed to large concentrations of lewisite, deep ulcers form.

Symptoms when inhaling gas:

damage to the mucous membrane of the nasopharynx, trachea, bronchi;
fluid from the nose;
sneezing, coughing;
headache;
nausea, vomiting;
loss of voice;
feeling of pressure in the chest, shortness of breath.

The mucous membrane of the eyes is highly sensitive to poisonous gas.. It becomes red, the eyelids swell, and lacrimation increases. A person experiences a burning sensation in the eyes. When liquid lewisite enters the gastrointestinal tract, the victim begins to drool profusely and vomit. Sharp pain in the abdominal cavity occurs. Internal organs are affected, and blood pressure drops sharply.

Hydrogen sulfide

Hydrogen sulfide is a colorless gas with a pungent odor of rotten eggs. In high concentrations the substance is very toxic. Entering the body by inhalation, symptoms of general intoxication develop - headache, dizziness, weakness. Hydrogen sulfide is quickly absorbed into the blood and affects the central nervous system.

Signs of gas poisoning:

metallic taste in the mouth;
paralysis of the nerve responsible for the sense of smell, so the victim immediately ceases to feel any odors;
respiratory tract damage, pulmonary edema;
severe cramps;
coma.

Carbon monoxide

Carbon monoxide is a colorless poisonous substance, lighter than air. Entering the body through the respiratory tract, it is quickly absorbed into the blood and binds to hemoglobin. This blocks the transport of oxygen to all cells, oxygen starvation occurs, and cellular respiration stops.

Symptoms of carbon monoxide poisoning:

dizziness and headache;
rapid breathing and heartbeat, shortness of breath;
noise in ears;
impaired visual acuity, flickering in the eyes;
skin redness;
nausea, vomiting.

In severe poisoning, convulsions are observed. Symptoms preceding coma increase - a drop in blood pressure, severe weakness, loss of consciousness. In the absence of medical assistance, death occurs within 1 hour.

Phosgene

Phosgene is a colorless gas with the odor of rotting hay. The substance is dangerous if inhaled, the first signs of intoxication appear after 4-8 hours. At high concentrations, death occurs within 3 seconds. Gas entering the lungs destroys them, causing instant swelling.

Symptoms at different stages of poisoning:

Pulmonary edema begins to develop in the latent period, when the victim is unaware of poisoning. The first signals from the body are a sweet, cloying taste in the mouth, nausea. Sometimes there is vomiting. A person feels a sore throat, itching and burning in the nasopharynx. A cough reflex occurs, breathing and pulse are disrupted.
After the latent period, the victim’s condition deteriorates sharply. A severe cough appears and the person begins to choke. The skin and lips turn blue.
The stage of progressive deterioration is severe pressure in the chest, leading to suffocation, the respiratory rate increases to 70 per minute (normal 18). A lot of fluid and mucus forms in the lungs due to the decomposition of the alveoli. A person coughs up sputum containing blood. Breathing becomes impossible. 50% of the bcc (circulating blood volume) goes to the lungs and increases them. The weight of one lung can be 2.5 kg (the norm is 500-600 g).

In severe cases, death within 10-15 minutes. In case of moderate gas poisoning, death occurs within 2-3 days. Recovery can occur 2-3 weeks after poisoning, but this is rare due to infection.

Hydrocyanic acid

Hydrocyanic acid is a colorless, light and mobile liquid with a pronounced odor. It blocks the chain of oxygen movement through tissues, causing tissue hypoxia. The gas affects the nervous system, disrupting the innervation of organs.

Symptoms of respiratory poisoning:

dyspnea;
at the beginning of the development of the clinical picture, rapid breathing;
with severe intoxication - respiratory depression and cessation.

Signs of the heart:

slowing down heart beats;
increased blood pressure;
vasospasm;
as symptoms increase - drop in pressure, increased heart rate, acute cardiovascular failure, cardiac arrest.

Poisonous gases are strong, fast-acting substances. To save a person, emergency resuscitation measures are necessary. If the outcome is favorable, the victim needs long-term rehabilitation treatment.

Carbon monoxide (carbon monoxide).

Carbon monoxide- a colorless, odorless gas, slightly lighter than air, poorly soluble in water, has a boiling point: - 191.5°C. In air it ignites at a temperature of 700°C and burns with a blue flame to CO 2 .

Sources of entry into the environment.

Carbon monoxide is part of the atmosphere (10%). Carbon monoxide enters the atmosphere as part of volcanic and swamp gases, as a result of forest and steppe fires, and emission by microorganisms, plants, animals and humans. From the surface layers of the oceans, 220 x 10 6 tons of carbon monoxide are released per year as a result of photodecomposition of red, blue-green and other algae, waste products of plankton. Natural levels of carbon monoxide in atmospheric air- 0.01-0.9 mg/m3.

Carbon monoxide enters the atmosphere from industrial enterprises, primarily metallurgy. In metallurgical processes, when smelting 1 million tons of steel, 320-400 tons of carbon monoxide are formed. A large number of CO is formed in the oil industry and chemical plants (oil cracking, production of formaldehyde, hydrocarbons, ammonia, etc.). Another important source of carbon monoxide is tobacco smoke. The concentration of carbon monoxide is high in coal mines and on coal supply routes. Carbon monoxide is formed during incomplete combustion of fuel in stoves and internal combustion engines. An important source of carbon monoxide is road transport.

As a result of human activity, 350-600x10 6 tons of carbon monoxide enter the atmosphere annually. About 56-62% of this amount comes from motor vehicles (the content of carbon monoxide in exhaust gases can reach 12%).

Behavior in environment.

Under normal conditions, carbon monoxide is inert. It does not chemically interact with water. The solubility of CO in water is about 1:40 by volume. In solution it is capable of reducing gold and platinum salts to free metals already at normal temperature. CO also does not react with alkalis and acids. Interacts with caustic alkalis only at elevated temperatures and high pressures.

The loss of carbon monoxide in the environment occurs due to its decomposition by soil fungi. In addition, when there is an excess of oxygen in soils of heavy mechanical composition, rich in organic matter, the transition of CO to CO 2 occurs.

Impact on the human body.

Carbon monoxide is extremely poisonous. The permissible CO content in industrial premises is 20 mg/m 3 during the working day, 50 mg/m 3 for 1 hour, 100 mg/m 3 for 30 minutes, in the atmospheric air of the city the maximum one-time (in 20 minutes) is 5 mg/m 3 , average daily MPC - 3 mg/m 3 . The natural level of carbon monoxide in atmospheric air is 0.01-0.9 mg/m3.

CO is inhaled along with air and enters the blood, where it competes with oxygen for hemoglobin molecules. Carbon monoxide, having a double chemical bond, binds to hemoglobin more firmly than an oxygen molecule. The more CO2 is in the air, the more hemoglobin molecules bind to it and the less oxygen reaches the body's cells. The ability of the blood to deliver oxygen to tissues is disrupted, vascular spasms are caused, a person’s immunological activity decreases, accompanied by headache, loss of consciousness and death. For these reasons, CO in elevated concentrations is a deadly poison.

CO disrupts phosphorus metabolism. Violation of nitrogen metabolism causes sotemia, changes in the content of plasma proteins, a decrease in the activity of blood cholinesterase and the level of vitamin B 6. Carbon monoxide affects carbohydrate metabolism, enhances the breakdown of glycogen in the liver, disrupting the utilization of glucose, increasing blood sugar levels. The entry of CO from the lungs into the blood is determined by the concentration of CO in the inhaled air and the duration of inhalation. CO is released mainly through the respiratory tract.

The central nervous system suffers most from poisoning. When inhaling a small concentration (up to 1 mg/l) - heaviness and a feeling of squeezing of the head, severe pain in the forehead and temples, dizziness, trembling, thirst, increased heart rate, nausea, vomiting, increased body temperature to 38-40 ° C. Weakness in the legs indicates that the action has spread to the spinal cord.

The extreme toxicity of CO, its lack of color and odor, as well as the very weak absorption of it by the activated carbon of a conventional gas mask make this gas especially dangerous.

Ammonia.

Ammonia- colorless gas with a pungent odor, melting point - 80°C, boiling point - 36°C, soluble in water, alcohol and a number of other organic solvents. Synthesized from nitrogen and hydrogen. In nature, it is formed during the decomposition of nitrogen-containing organic compounds.

Being in nature.

In nature, it is formed during the decomposition of nitrogen-containing organic compounds.

The pungent odor of ammonia has been known to man since prehistoric times, since this gas is formed in significant quantities during the rotting, decomposition and dry distillation of nitrogen-containing organic compounds, such as urea or proteins. It is possible that in the early stages of the Earth's evolution there was quite a lot of ammonia in its atmosphere. However, even now, tiny amounts of this gas can always be found in the air and in rainwater, since it is continuously formed during the decomposition of animal and plant proteins.

Anthropogenic sources of entry into the environment.

The main sources of ammonia emissions are nitrogen fertilizer plants and enterprises producing nitric acid and ammonium salts, refrigeration units, coke plants and livestock farms. In areas of technogenic pollution, ammonia concentrations reach values of 0.015-0.057 mg/m 3, in control areas - 0.003-0.005 mg/m 3.

Effect on the human body.

This gas is toxic. A person is able to smell ammonia in the air already in an insignificant concentration - 0.0005 mg/l, when there is still no great danger to health. When the concentration increases 100 times (up to 0.05 mg/l), the irritating effect of ammonia on the mucous membrane of the eyes and upper respiratory tract is manifested, and even a reflex cessation of breathing is possible. Even a very healthy person can hardly withstand a concentration of 0.25 mg/l for an hour. Even higher concentrations cause chemical burns to the eyes and respiratory tract and become life-threatening. The external signs of ammonia poisoning can be quite unusual. In victims, for example, the hearing threshold sharply decreases: even not too loud sounds become unbearable and can cause convulsions. Ammonia poisoning also causes strong agitation, even violent delirium, and the consequences can be very severe - leading to a decrease in intelligence and personality changes. Obviously, ammonia can attack vital centers, so careful precautions must be taken when working with it.

Chronic exposure to sublethal doses of ammonia leads to autonomic disorders, increased excitability of the parasympathetic nervous system, complaints of weakness, malaise, runny nose, cough, and chest pain.

Substance hazard class - 4.

APPENDIX 7. Characteristics of explosive and harmful gases most often found in tanks and underground structures.

The following explosive and harmful gases are most often found in underground structures: methane, propane, butane, propylene, butylene, carbon monoxide, carbon dioxide, hydrogen sulfide and ammonia.

Methane CH 4 (swamp gas) is a colorless, odorless, flammable gas, lighter than air. Penetrates into underground structures from the soil. It is formed during the slow decomposition of plant substances without access to air: during the rotting of fiber under water (in swamps, stagnant waters, ponds) or the decomposition of plant residues in coal deposits. Methane is a component of industrial gas and, if the gas pipeline is faulty, can penetrate into underground structures. It is not toxic, but its presence reduces the amount of oxygen in the air of underground structures, which leads to disruption of normal breathing when working in these structures. When the methane content in the air is 5-15% by volume, an explosive mixture is formed.

Propane C3H8, butane C4H10, propylene C 3 H 6 and butylene C 4 H 8 - colorless flammable gases, heavier than air, odorless, difficult to mix with air. Inhaling propane and butane in small quantities does not cause poisoning; propylene and butylene have a narcotic effect.

Liquefied gases with air can form explosive mixtures at the following content, % by volume:

Propane………………… 2.3 – 9.5

Butane…………………. 1.6 - 8.5

Propylene………………. 2.2 - 9.7

Butylene……………….. 1.7 – 9.0

Protective equipment - hose gas masks PSh-1, PSh-2.

Carbon monoxide CO is a colorless, odorless, flammable and explosive gas, slightly lighter than air. Carbon monoxide is extremely poisonous. The physiological effects of carbon monoxide on humans depend on its concentration in the air and the duration of inhalation.

The means of protection is a CO filter gas mask.

Carbon dioxide CO 2 [carbon dioxide (dioxide)] is a colorless, odorless gas with a sour taste, heavier than air. Penetrates into underground structures from the soil. Formed as a result of the decomposition of organic substances. It is also formed in reservoirs (tanks, bunkers, etc.) in the presence of sulfonated coal or coal due to its slow oxidation.

Protective equipment - hose gas masks PSh-1, PSh-2.

Hydrogen sulfide H 2 S is a colorless flammable gas, has the smell of rotten eggs, and is somewhat heavier than air. Poisonous, affects the nervous system, irritates the respiratory tract and the mucous membrane of the eyes.

When the hydrogen sulfide content in the air is 4.3 - 45.5% by volume, an explosive mixture is formed.

The means of protection is filtering gas masks of brands B, KD.

Ammonia NH 3 is a colorless flammable gas with a sharp characteristic odor, lighter than air, toxic, irritates the mucous membrane of the eyes and respiratory tract, causes suffocation. When the ammonia content in the air is 15-28% by volume, an explosive mixture is formed.

The means of protection is a filter gas mask of the KD brand.

Hydrogen H 2 is a colorless, odorless, tasteless flammable gas, much lighter than air. Hydrogen is a physiologically inert gas, but at high concentrations it causes asphyxiation due to a decrease in oxygen content. When acid-containing reagents come into contact with the metal walls of containers that do not have an anti-corrosion coating, hydrogen is formed. When the hydrogen content in the air is 4-75% by volume, an explosive mixture is formed.

Oxygen O 2 is a colorless gas, odorless and tasteless, heavier than air. Toxic properties does not, but with prolonged inhalation of pure oxygen (at atmospheric pressure), death occurs due to the development of pleural pulmonary edema.