Nitrogen oxides (N x O y ) hazard class-3
Nitric oxide ( NO ) - colorless gas with a liquefaction temperature of -151.6°Chardening -163.6°C. Poorly soluble in water. Nitrogen dioxide ( NO2) – pale yellow liquid with a solidification point of -11.2°C, boils at a temperature of +21°C. The vapors are heavier than air, have a brown color and a suffocating odor. Forms nitric acid with water. It is a strong oxidizing agent: organic mixtures ignite, mixtures with methane and butane explode.
Nitrogen oxides apply in the production of nitric acid (intermediate products), are oxidizing agents in liquid rocket fuel, are used in the purification of petroleum products from organosulfur compounds, and are used as catalysts for the oxidation of organic compounds.
Nitrogen oxides are transported V railway and roadtanks, containers and cylinders that are temporarily storedshem. Typically, nitrogen oxides are stored invertical cylindrical (volume 50 - 5000 m3) or horizontal cylindrical (volume 5 - 100 m3) tanks at atmospheric pressure and at ambient temperature.
Maximum permissible concentration (MPC) nitrogen oxide (dioxide) in the air of populated areas is 0.085 (0.6)mg/m3, in the air of the working area 5,0 (2,0) mg/m3. Olfactory threshold (for nitric oxide) 10 mg/m3. At a concentration of 90 mg/m 3 for 15 minutes, irritation of the pharynx, urge to cough, and salivation are observed. Concentrations of 200-300 mg/m 3 are considered dangerous for short-term exposure; concentrations no higher than 70 mg/m 3 are tolerable for long-term exposure.
When eliminating accidents associated with the release (spill) of nitrogen oxidesisolate the danger zone, remove people from it, stay to the windward side, avoid low places, enter the accident zone only in full protective clothing. Directly at the scene of the accident and near the source of infection, work is carried out in isolating gas masks or breathing apparatus (IP-4m, ASV-2, AP-96, KIP-8) and skin protection means (L-1, KIKH-4, KIKH-5, etc. .). To escape the infection zone and when working in emergency conditions at a distance of 300-500 m from the source of infection, filtering industrial gas masks with grade B boxes and a universal protective cartridge PZU-K are used.
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Means of protection |
Time of protective action (hour) at concentrations (mg/m 3) |
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Name |
Brand boxes |
5000 |
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Industrial gas masks: large size |
In s/ f In s/ f |
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Universal protective cartridge |
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Rocket Forces Gas Mask |
PRV-M (R) |
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The presence of nitrogen oxides is determined by:
Universal gas analyzer UG-2 with an indicator tube for nitrogen oxides with a measurement range of 0-200 mg/m3;
Mini-express laboratory MEL with measurement range 2.5-50 mg/m3;
Chemical gas detector of industrial emissions GKhPV-2 with an indicator tube for nitrogen oxides with a measurement range of 0-30, 0-200 mg/m 3 ;
Laboratory "Pchelka-R" using indicator tubes for nitrogen oxides with a measurement range of 2.5-50.1-100 mg/m3;
Stationary gas analyzer ESSA;
Personal indicator-signaling device "MEGAKON".
Neutralizes nitrogen oxides 10% alkali solution(for example, 100 kg of caustic soda and 900 liters of water) or water with a consumption of 8-9 tons per 1 ton of nitrogen oxides. If necessary lowering the freezing point of an alkali solution add monoethanolamine.
Sprayed water is used to deposit vapors. For spraying water or solutions, auto-filling stations (ARS-14, ARS-15), special thermal machines (TMS-65), fire engines, as well as hydrants and special systems available at chemically hazardous facilities are used.
In the case of a spill of liquefied nitrogen oxides, the spill site is washed with a large amount of water, isolated with sand, air-mechanical foam, diked and the substances are not allowed to enter surface waters. For disposal of contaminated soil at the spill site during neutralizationnitrogen oxides cut off the surface layer of soil to the depth of contamination,collected and transported for disposal using earth-moving machines(bulldozers, scrapers, motor graders, dump trucks). Places of cuts are coveredwith a fresh layer of soil, washed with water for control purposes.
Leader actions: isolate the danger zone, remove people from it, stay to windward, avoid low places, do not smoke. Enter the accident area only in full protective clothing.
Providing first aid:
In the contaminated area: abundantly washing the eyes with water or a 2% solution of baking soda, putting a gas mask on the victim, evacuation on a stretcher by transport.
After evacuation from the contaminated area : abundant eye rinsing with water or a 2% solution of baking soda, treatment of affected skin areas with water, soap solution, rest, immediate evacuation to a medical facility. Inhalation of the anti-smoke mixture for several minutes, chromosmon 20-40 ml intravenously, drip. Do not inhale oxygen.
Phenol is an organic chemical substance, a hydrocarbon. Other names: carbolic acid, hydroxybenzene. It comes in natural and industrial origin. What is phenol and what is its significance in human life?
Origin of the substance, chemical and physical properties
The chemical formula of phenol is c6h5oh. In appearance, the substance resembles crystals in the form of needles, transparent, with a white tint. In the open air, when exposed to oxygen, the color becomes light pink. The substance has a specific odor. Phenol smells like gouache paint.
Natural phenols are antioxidants that are present in varying quantities in all plants. They determine color, aroma, and protect plants from harmful insects. Natural phenol is beneficial for the human body. It is found in olive oil, cocoa beans, fruits, and nuts. But there are also toxic compounds, such as tannin.
The chemical industry produces these substances through synthesis. They are poisonous and very toxic. Phenol is dangerous for humans, and the industrial scale of its production significantly pollutes the environment.
Physical properties: 
- Phenol dissolves normally in water, alcohol, alkali;
- has a low melting point, at 40°C it turns into gas;
- its properties are in many ways similar to alcohol;
- has high acidity and solubility;
- at room temperature they are in a solid state;
- The smell of phenol is pungent.
How are phenols used?
More than 40% of the substances are used in the chemical industry to produce other organic compounds, mainly resins. It is also made from artificial fibers - nylon, nylon. The substance is used in the oil refining industry to purify oils that are used in drilling rigs and other technological facilities.
Phenol is used in the production of paints and varnishes, plastics, and in chemicals and pesticides. In veterinary medicine, farm animals are treated with the substance to prevent infections.
The use of phenol in the pharmaceutical industry is significant. It is included in many medications:
- antiseptics;
- painkillers;
- antiplatelet agents (thin the blood);
- as a preservative for vaccine production;
- in cosmetology as part of preparations for chemical peeling.
In genetic engineering, phenol is used to purify DNA and extract it from cells.
Toxic effect of phenol
Phenol is poison. In terms of its toxicity, the compound belongs to hazard class 2. This means that it is highly hazardous to the environment. The degree of impact on living organisms is high. The substance can cause serious damage to the ecological system. The minimum recovery period after the action of phenol is at least 30 years, provided that the source of pollution is completely eliminated.
Synthetic phenol has a negative effect on the human body. Toxic effect of the compound on organs and systems:
- If vapors are inhaled or swallowed, the mucous membranes of the digestive tract, upper respiratory tract, and eyes are affected.
- If it comes into contact with the skin, a phenol burn will form.
- With deep penetration it causes tissue necrosis.
- Has a pronounced toxic effect on internal organs. When the kidneys are damaged, it causes pyelonephritis, destroys the structure of red blood cells, which leads to oxygen starvation. Can cause allergic dermatitis.
- When phenol is inhaled in high concentrations, brain activity is disrupted and can lead to respiratory arrest.
The mechanism of the toxic effect of phenols is a change in the structure of the cell and, as a consequence, its functioning. Neurons (nerve cells) are the most susceptible to toxic substances.
Maximum permissible concentration (MPC of phenol):
- the maximum single dose in the atmosphere for populated areas is 0.01 mg/m³, which remains in the air for half an hour;
- the average daily dose in the atmosphere for populated areas is 0.003 mg/m³;
- the lethal dose when ingested is for adults from 1 to 10 g, for children from 0.05 to 0.5 g.
Symptoms of phenol poisoning
The harm of phenol to living organisms has long been proven. When it comes into contact with the skin or mucous membranes, the compound is quickly absorbed, overcomes the hematogenous barrier and spreads through the blood throughout the body.
The brain is the first to respond to the effects of poison. Signs of poisoning in humans:
- Psyche. Initially, the patient experiences mild excitement, which does not last long and is replaced by irritation. Then comes apathy, indifference to what is happening around, the person is in a depressed state.
- Nervous system. General weakness, lethargy, loss of strength increases. Tactile sensitivity is blurred, but the reaction to light and sounds is exacerbated. The victim feels nausea, which is not related to the functioning of the digestive system. Dizziness appears and the headache becomes more intense. Severe poisoning can lead to convulsions and unconsciousness.
- Skin. The skin becomes pale and cold to the touch, and in severe cases acquires a blue tint.
- Respiratory system. If even small doses enter the body, a person may experience shortness of breath and rapid breathing. Due to irritation of the nasal mucosa, the victim is continuously sneezing. In case of moderate poisoning, a cough and spastic contractions of the larynx develop. In severe cases, the threat of spasm of the trachea and bronchi increases and, as a result, suffocation, leading to death.
Circumstances under which poisoning can occur are violation of safety rules when working with particularly dangerous substances, overdose of medications, household poisoning with detergents and cleaning products, as a result of an accident.
If the house contains low-quality furniture, children's toys that do not meet international safety standards, or the walls are painted with paint that is not intended for these purposes, then the person constantly inhales the emanating phenol vapors. In this case, chronic poisoning develops. Its main symptom is chronic fatigue syndrome.
Principles of first aid
The first thing to do is to interrupt human contact with the poisonous source.
Take the victim out of the room into fresh air, unfasten buttons, locks, and zippers to better ensure access to oxygen.
If the phenol solution gets on your clothing, remove it immediately. Rinse the affected skin and mucous membranes of the eyes thoroughly and repeatedly with running water.
If phenol gets into the mouth, do not swallow anything, but immediately rinse your mouth for 10 minutes. If the substance has managed to enter the stomach, you can drink the sorbent with a glass of water:
- activated or white carbon;
- enterosorb;
- enterosgel;
- sorbex;
- carbolene;
- polysorb;
- lactofiltrum.
You should not rinse the stomach, as this procedure will increase the severity of the burn and increase the area of damage to the mucous membrane.
Phenol antidote is a solution of calcium gluconate for intravenous administration. In case of poisoning of any severity, the victim is taken to the hospital for observation and treatment.
In case of severe poisoning, phenol can be removed from the body in a hospital setting using the following methods:
- Hemosorption is the purification of blood with a special sorbent that binds molecules of a toxic substance. The blood is purified by passing through a special apparatus.
- Detoxification therapy is the intravenous infusion of solutions that dilute the concentration of a substance in the blood and promote its natural elimination from the body (through the kidneys).
- Hemodialysis is indicated in severe cases where there is a potential threat to life. The procedure is carried out using an “artificial kidney” apparatus, in which the blood passes through special membranes and leaves molecules of a toxic substance. Blood returns to the body clean and saturated with useful microelements.
Phenol is a synthetic toxic substance that is dangerous to humans. Even a naturally occurring compound can be harmful to health. To avoid poisoning, it is necessary to responsibly work in production where there is a risk of contact with poison. When shopping, be interested in the composition of the products. The unpleasant smell of plastic products should alert you. When using medications containing phenol, follow the prescribed dosage.
THE PROBLEM OF THE SCIENTIFIC VALUE OF FORMALDEHYDE MAC FOR RESIDENTIAL AIR HAS BECOME ONE OF THE MOST TOPIC TOPICS OF ECOLOGICAL DISCUSSIONS IN OUR COUNTRY. NOT BECAUSE SOMEONE DEFENDS “HARMFUL FORMALDEHYDE,” BUT BECAUSE IN THE DURING EXCHANGE OF VIEWS REVEALS A DISMISSING PICTURE OF INACCURACY OF MEASUREMENTS IN THE PRACTICE OF DETECTING THE RELEASE OF HARMFUL ORGANIC SUBSTANCES - FORMALDEHYDE, METHANOL, PHENOL. BUT PRECISION INSTRUMENTS - GAS CHROMATOGRAPHES ARE NOT USED.
AND THE MAC VALUES ARE CONTRARY TO EXISTING WORLD PRACTICE.
Victor Khabarov,
Art. Researcher, Ph.D. in Chemistry,
Institute of Physical Chemistry
and Electrochemistry named after. A.N. Frumkin RAS
Development of production and use of composite wood materials (CWM) - plywood, particle boards (chipboards), oriented strand boards (OSB) and wood fiber boards (FRP) based on urea-, melamine- and phenol-formaldehyde (KF, MF, FF) ) resins in civil and industrial construction, for the manufacture of furniture, etc. put forward increased requirements for the qualitative and quantitative reliability of the results of sanitary-chemical assessment of CDM under simulated and natural operating conditions for formaldehyde, methanol, phenol and ammonia. Numerous scientific studies in this area say that environmental problems in the production and use of composite wood materials are the result of: - the adoption of a scientifically unsubstantiated maximum permissible concentration (MAC) of formaldehyde of 0.01 mg/m3 for residential air; - reducing the maximum permissible concentration for air in residential premises for phenol from 0.01 to 0.003 mg/m3 and ammonia from 0.2 to 0.04 mg/m3; - unsecured receipt of reliable quantitative results by standards for determining the release and content of formaldehyde in plywood and chipboard by the spectrophotometric method with an acetylacetone reagent; - non-use of gas chromatography (GC) methods to determine the sanitary and chemical characteristics of plywood, chipboard, OSB, fiberboard, CF and MF resins; - lack of regulation by GOSTs of the content of methanol and methylal in CF and methanol in FF resins; - the use of stainless steel chambers to simulate operating conditions during sanitary-chemical assessment of CDM, which do not provide reliable quantitative results for formaldehyde, methanol, phenol and ammonia
ABOUT THE VALIDITY OF MAC FORMALDEHYDE, METHANOL, PHENOL AND AMMONIA
The evidence base for the scientific unsubstantiation of the maximum permissible concentration of formaldehyde for residential air is:
1) the results of a sanitary-chemical assessment of solid pine and birch wood under simulated operating conditions in glass chambers using the GC method;
2) use of an aqueous solution of formaldehyde to construct a calibration graph for the photometric determination of formaldehyde in air with an acetylacetone reagent and chromotropic acid.
The failure to use the GC method and the use of an aqueous solution of formaldehyde to construct a calibration curve when determining the latter in the air led to the erroneous determination of the maximum permissible concentration of formaldehyde - 0.01 mg/m3 for residential air in Russia. This is due to the fact that aqueous solutions of formaldehyde are an equilibrium mixture of methylene glycol monohydrate CH2(OH)2 and a number of hydrated low molecular weight polymers or polyoxymethylene glycols with the general formula HO(CH2O)nH. The state of equilibrium depends on the temperature and concentration of formaldehyde in the solution.
An expert assessment of existing spectrophotometric methods for determining formaldehyde showed that determination methods with chromotropic acid and acetylacetone are non-selective and have a lower limit for the determined formaldehyde content of 0.06 mg/m3 when taking 15 liters of analyzed air. The sampling technique has not been developed. The influence of accompanying methanol, phenol and other toxic components on the analysis results is not taken into account. Therefore, these methods are incorrect in some cases and cannot provide reliable results, especially when the concentration of formaldehyde in the air is below 0.06 mg/m3.
The researchers' sanitary-chemical assessment of pine and birch solids using the GC method shows that the release of formaldehyde from pine solid wood after 6 months of sample conditioning under simulated operating conditions at a saturation of 2.2 m2/m3, temperatures of 20, 40 ° C and gas exchange 1 volume/hour is 0.15 mg/m3 and 0.165 mg/m3 and exceeds the maximum permissible concentration of formaldehyde for residential air by 15–17 times. The concentration of formaldehyde 0.15 mg/m3, released from solid pine wood under simulated operating conditions at a temperature of 20°C, should be the maximum permissible concentration of formaldehyde for the air of residential premises. The experience of civilizations has shown that the best material for building housing for humans is wood, which is considered harmless. The World Health Organization (WHO) recommended a maximum permissible concentration of formaldehyde of 0.1 mg/m3 for indoor air and ambient air. To control this standard of formaldehyde in the air, methods based on high-performance liquid chromatography (HPLC) are used. In Germany, there is a ban on the use of wood materials (with or without coating) whose level of formaldehyde migration into the air exceeds 0.1 ppm (0.124 mg/m3). The same indicator is established for furniture. In member countries of the World Trade Organization (WTO), the formaldehyde standard for wood boards and other polymer-containing wood building materials is adopted at the level of 0.124 mg/m3.
In Russia, the guidelines for sanitary and hygienic control of polymer building materials included a list of “Acceptable Levels (AL) for the release of harmful chemicals from polymer building materials,” which contained 68 chemical compounds. Today, neither on the website of Rospotrebnadzor nor on the website of the information and reference systems Codex and Tekhekspert, you will find information about the cancellation by the Chief Sanitary Doctor of Russia of the list “Permissible levels of release of harmful chemicals from polymer building materials.” The question arises: on what basis is this list not included in the new guidelines? Today, the maximum permissible concentrations used in the practice of Rospotrebnadzor authorities for residential air are the most stringent in the world: formaldehyde 0.01 mg/m3, phenol 0.003 mg/m3, ammonia 0.04 mg/m3. They lead to the fact that all construction technologies using plywood, fiberboard and chipboard are already subject to prohibition. Based on what scientific data did Rospotrebnadzor tighten the standards for phenol by 3.3 times, and ammonia by 5 times for residential air?
ABOUT REGULATIVE DOCUMENTS
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The provisions of the laws of the Russian Federation “On technical regulation”, “On sanitary and epidemiological welfare of the population”, “On ensuring uniformity of measurements”, “On standardization”, “On certification” and GOST R must be carried out not only by independent testing laboratories, but also be in area of responsibility of manufacturers of composite resins and synthetic resins. The scientific community conducted a comparative expert analysis of regulatory documents on the sanitary and chemical characteristics of plywood used in civil engineering, transport facilities, and for the manufacture of furniture, operating in the European Union and Russia.
Currently, EU countries use standards to determine the safety indicators of plywood, chipboard and fiberboard only for formaldehyde using the spectrophotometric method with an acetylacetone reagent. The standards do not provide for the determination of methanol and phenol.
The European Union has adopted standards for determining the sanitary and chemical characteristics of plywood, which are used when concluding contracts for its purchase. The EN 1084:1995 standard establishes three classes of formaldehyde emission: A, B, C (at saturation of the chamber volume with the plywood surface of 0.06 cm2/m3, temperature 60°C and gas exchange 15 volumes/hour for 4 hours), which are determined according to the standard EN 717-2-1995 spectrophotometric method with acetylacetone reagent. Class A - up to 3.5 mg/m2 h; class B - 3.5–8.0 mg/m2 h; C - more than 8 mg/m2 h. Standard EN 1084:1995 applies to plywood, chipboard and fibreboard based on CF and
MF resins. The standard should not apply to plywood, chipboard and fiberboard based on FF resins. In Germany, plywood of formaldehyde emission classes B and C is not permitted for use. The domestic GOST R 53867, adopted in 2010, duplicates the European Union standard EN 717-2-1995. In Russia, to determine the safety indicators of plywood, chipboard, fiberboard for formaldehyde, they use the titrimetric method (GOST 27678-88), the spectrophotometric method with an acetylacetone reagent (GOST 30255-95 and GOST R 53867-2010) and do not control the determination of methanol and phenol. GOSTs do not meet the level of requirements of the WTO countries and the modern requirements of the domestic market.
In addition to the current standards of the European Union countries for the determination of formaldehyde released from CDM by the spectrophotometric method with an acetylacetone reagent, the WTO member countries have adopted standards that are used for the determination of formaldehyde in air by the HPLC method with a UV detector (GOST R ISO 16000-3-2007 and 16000 -4-2007). The standards for the determination of formaldehyde by the HPLC method are inferior in sensitivity and accuracy to the method based on gas chromatography - the standard of the NIOKO Bioekomonitoring enterprise, which provides for the determination of formaldehyde, methanol, methylal in a sample and the selective determination of phenol released from CDM.
TO INNOVATIVE METHODOLOGY
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Meanwhile, it is in Russia that certain positive results have been achieved in the field of metrological quality assurance and compliance with the requirements of the safety indicators of CDM after the introduction in 1996 of the standard of the NIOKO “Bioekomonitoring” gas chromatographic technique, which is protected by 8 copyright certificates of the USSR and set out in articles. For KDM manufacturers, this innovative methodology for determining the sanitary-chemical characteristics of boards and synthetic resins by this method is very important. Therefore, we will tell her in more detail. The GC technique is intended for
definitions:
Formaldehyde, methanol, methylal and phenol released from plywood, chipboard, OSB and fiberboard based on synthetic resins under simulated operating conditions at saturation 0.4–2.2 m2/m3, temperature 20, 40°C and gas exchange 0.5– 5.0 volume/h;
- formaldehyde, methanol, methylal and phenol are also determined by GC and headspace analysis (PPA) in CDM and synthetic resins at a temperature of 80–85°C;
- by capillary GC method: volatile organic substances released from CDM based on synthetic resins under simulated operating conditions.
Measurement of the concentrations of chemicals - formaldehyde, methanol, methylal and phenol, released from plywood, chipboard, OSB and fiberboard, is carried out under simulated operating conditions (mg/m3, mg/m2 h) and the residual content of chemicals (mg/100 g, % wt.) in CDM by GC and dynamic PFA. Phenol is determined separately from formaldehyde, methylal and methanol. For concentrated phenol, a heat-resistant porous polymer sorbent, Polychrome-3, is used, which does not concentrate formaldehyde, methylal and methanol at room temperature. To concentrate formaldehyde and methanol, heat-resistant porous polymer sorbents polyphenylquinoxaline or cesium sorb are used. Concentrated phenol, formaldehyde and methanol from the concentrator cartridge are introduced into the analytical column by thermal desorption using a device that eliminates the impenetrable volume between the concentrator cartridge needle and the gas chromatograph evaporator membrane.
The determination of formaldehyde, methylal and methanol in KDM and KF resins is carried out by GC and dynamic PFA at a temperature of 80–85°C by introducing a vapor-gas sample into the analytical column using a PFA device with a 15 cm3 loop. Determination of formaldehyde, methylal and methanol is carried out on a column with polyphenylquinoxaline, and phenol - on a column with 2% polyethylene glycol adipate (PEGA) on polychrome-1. Glass capillary columns (GCC) with SE-30 and NaCl and much more are used to identify volatile organic compounds released from the CDM under simulated operating conditions.
EXPERIMENTAL STUDIES
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Experimental studies of the determination by GC of the sanitary-chemical characteristics of plywood based on KF, FF resins and KF resins have been published and the results of their sanitary-chemical assessment are presented. It was carried out under simulated operating conditions using the GC method and the spectrophotometric method with an acetylacetone reagent, and the content of organic substances in the CP resin was determined (Table 2). From Table 2 it follows that the sanitary-chemical assessment of plywood by GC on a glass capillary column (GCC) with SE-30 and NaCI depends on the veneer drying mode and the type of coolant. Plywood made from birch veneer, dried in a gas dryer with gases when burning natural gas, releases 26 organic substances, and from birch veneer, dried in a gas dryer with gases when burning wood, - 60 organic substances. Birch veneer dried in a steam dryer releases 18 organic substances. Comparison of results (Table 2) plywood with a thickness of 8, 9, 15 and 18 mm under simulated operating conditions according to the standard of the NIOKO Bioekomonitoring enterprise shows that the concentrations of formaldehyde emission (mg/m2 h) obtained by GC are 2.2–4.9 times lower compared to the spectrophotometric method used by the European Union with an acetylacetone reagent, where the standard determines the amount of organic substances that are mistaken for formaldehyde.
Plywood according to the class of formaldehyde emission according to the standard by the GC method corresponds to class B, and by the spectrophotometric method with an acetylacetone reagent - to class C. It is clear why the standards of the European Union countries underestimate the grade of plywood and, accordingly, the prices for it. From Table 2 it follows that the CP resin samples contain methylal along with formaldehyde and methanol. KF resin of grades KF 115-53 and KFMT-15 contains, respectively, 1.9 and 2.9 times more methanol and 1.4 and 2.5 times more methylal compared to formaldehyde. No methylal was detected in the plywood samples studied by GC, which indicates its decomposition during plywood pressing. Plywood samples containing resins and lignosulfonates in the CF composition emit 4.2–4.7 times more methanol compared to plywood that does not contain lignosulfonates. The sanitary and chemical characteristics of plywood based on KF resin, birch veneer and KF resin were obtained by GC using a PFA device (Table 3–5). Polyphenylquinoxaline was used to separate a mixture containing formaldehyde, methanol, water, and methylal. A comparison of the results in Table 3 shows that when determined by GC using a PFA device, plywood contains 7–8 times more methanol compared to formaldehyde. The formaldehyde content in plywood, determined by the GC method, is 3.6–7.4 times lower compared to the titrimetric method according to GOST. When determining formaldehyde in plywood in accordance with GOST 27678-88, the amount of organic substances that is mistakenly mistaken for formaldehyde is determined.
It also follows from Table 3 that birch veneer dried in a gas dryer contains 1.3 times more formaldehyde and 1.6 times less methanol compared to birch veneer dried in a steam dryer. In birch veneer dried in a gas dryer, the increased content of formaldehyde is due to the fact that when natural gas is burned, formaldehyde is formed, which is sorbed by the veneer in the gas dryer, and the reduced methanol content is associated with a more stringent drying regime for veneer in a gas dryer compared to a steam dryer. . When determining volatile organic substances in CF resin by GC, the same methodological approach was used as in plywood and veneer (Table 3). The dynamics of the release of formaldehyde, methanol and methylal from CP resin at a temperature of 80°C occurs due to diffusion.
From Table 4 it follows that the KFMT-15 resin contains 2.4 times more methanol and 3.6 times more methylal compared to formaldehyde. Methylal is formed during storage of technical solutions of formaldehyde (Walker J. Formaldehyde / Translated from English. M.: Goskhimizdat, 1957. - 608 p.).
Determination of volatile organic compounds released from plywood based on CF resin under simulated operating conditions (Table 5). From Table 5 it follows that plywood with a thickness of 9 and 18 mm at a saturation of 0.4 and 1.0 m2/m3 emits formaldehyde above the maximum permissible concentration for residential air by 2.2–8.0 times. Plywood 18 mm thick at a saturation of 1 m2/m3 emits methanol 1.8 times higher than the maximum permissible concentration and 4–13 times more than formaldehyde. This may be due to the following factors:
1) When synthesizing CP resin, an aqueous solution of formaldehyde containing high concentrations of methanol was used.
2) When storing aqueous solutions of formaldehyde, the following changes may occur to them:
a) the Cannizzaro reaction, which consists of the oxidation of one molecule of formaldehyde to formic acid and the reduction of another to methanol; b) formation of methylal. Using the GC method, a sanitary-chemical assessment of Russian plywood 10 mm thick from pine veneer based on KF and FF resins was also carried out, under simulated operating conditions (Table 6).
It has been established that the concentrations of volatile organic substances released from this plywood (based on KF resin at a saturation of 0.4–2.2 m2/m3) exceed the maximum permissible concentration for formaldehyde by 7–40 times and do not exceed the maximum permissible concentration for methanol; and based on FF resin at a saturation of 0.4–1.2 m2/m3 exceeds the maximum permissible concentration for formaldehyde by 8–25 times and does not exceed for methanol and phenol, and at a saturation of 2.2 m2/m3 exceeds the maximum permissible concentration for formaldehyde by 46 times , methanol - 1.8 times and phenol - 5.7 times.
THANKS TO WHOM THE EU COUNTRIES REDUCED THE GRADE OF PLYWOOD
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As we can see, to determine the sanitary-chemical characteristics of CDM and synthetic resins, it is necessary to use the GC method, dynamic PFA and heat-resistant polymer sorbents for concentrated - polychrome-3, cesium sorb and polyphenylquinoxaline. Polychrome-3 at room temperature selectively concentrates phenol released from the CDM from the gaseous medium, but does not concentrate formaldehyde and methanol. Polyphenylquinoxaline and cesium sorb concentrate formaldehyde and methanol. The use of these sorbents makes it possible to implement a methodological approach to the separate analysis of phenol and formaldehyde at room temperature. The GC method, the principle diagram of its implementation, and the device were once adopted in our country. It turned out to be quite accessible. However, subsequent events, the collapse of science, slowed down the implementation. We believe that now is his time.
It is needed by manufacturers of composite materials and synthetic resins, and will provide invaluable assistance to technologists and environmentalists. Absolutely accurate data from its analysis show that under simulated operating conditions in mg/m2 h at a temperature of 60°C, formaldehyde release concentrations obtained by GC are 2.2–4.9 times lower compared to the spectrophotometric method with acetylacetone reagent . The chromatographic method shows that with the determination of the release of harmful substances from CDM - plywood, chipboard, OSB, fiberboard and other materials, everything is completely different from what those who came up with standards for the content of formaldehyde in CDM and approved methods for the spectrophotometric determination of formaldehyde imagine.
After all, these methods do not provide accurate measurements of the release
formaldehyde, but lead to very undesirable consequences. European Union standards EN 1084:1995 and EN 717-2-1995 lower the grade of plywood and, accordingly, the price of plywood. Russian plywood producers and exporters are losing currency, but they cannot prove that their products are high-grade, which is why in Russia they do not use gas chromatographic methods for determining formaldehyde. The Law of the Russian Federation “On Ensuring the Uniformity of Measurements” allows the use for certification of KDM not only state-certified methods for determining harmful organic substances, but also methods in the form of an enterprise standard, which must be developed in accordance with GOST 8.563-2009 “Measurement techniques (methods)” and pass metrological certification.
It is obvious that our ministries, Rosprirodnadzor and all companies who truly care about the environment, the safety of materials, human safety and business profitability, need to make a turn towards reliable control over the release of not only formaldehyde from CDM, but also methanol and phenol.
Read the full article in the magazine “Chemistry and Business”
№ 5-6 (192)
© Chemistry and business. Republishing information only when indicated
In cities, the air is heavily polluted by harmful emissions from vehicles and industrial enterprises, which emit a whole range of substances, each of which negatively affects human health with varying degrees of intensity.
For all pollutants, there are standards for maximum permissible concentrations (maximum permissible concentrations) of substances in the air. Compliance with these standards should be monitored by special bodies (in Moscow this is the State Public Administration “Mosekomonitoring”) and in case of systematic violation, certain sanctions should be imposed: from a fine to the closure of an enterprise.
This page provides brief characteristics of some of the most common harmful substances emitted into the air by vehicles and industrial enterprises.
Hazard class of harmful substances- a conditional value intended for a simplified classification of potentially hazardous substances.
Standard GOST 12.1.007-76 “Classification of hazardous substances and general safety requirements” establishes the following criteria for determining Hazard class of harmful substances:
Based on the degree of impact on the body, harmful substances are divided into four hazard classes:
I substances are extremely dangerous
II highly hazardous substances
III moderately hazardous substances
IV low-hazard substances
MPC- maximum permissible concentration of a pollutant in the atmospheric air - a concentration that does not have a direct or indirect adverse effect on the present or future generation throughout life, does not reduce a person’s performance, does not worsen his well-being and sanitary living conditions.
PDKss- maximum permissible average daily concentration of a chemical substance in the air of populated areas, mg/m3. This concentration should not have any direct or indirect harmful effects on humans if inhaled indefinitely (years).
Characteristics of harmful substances.
Sulfur dioxide (sulfur dioxide) SO2
Hazard class - 3
MPCss - 0.05
MPCmr - 0.5
Colorless gas with a characteristic pungent odor. Toxic.
In mild cases of sulfur dioxide poisoning, cough, runny nose, lacrimation, dry throat, hoarseness, and chest pain appear; in case of acute poisoning of moderate severity, in addition, headache, dizziness, general weakness, pain in the epigastric region; upon examination, there are signs of a chemical burn of the mucous membranes of the respiratory tract.
Long-term exposure to sulfur dioxide can cause chronic poisoning. It manifests itself as atrophic rhinitis, dental damage, often aggravated by toxic bronchitis with attacks of suffocation. Possible damage to the liver, blood system, and development of pneumosclerosis.
Particularly high sensitivity to sulfur dioxide is observed in people with chronic respiratory disorders and asthma.
Sulfur dioxide is formed when reserve fuels are used by thermal power complex enterprises (fuel oil, coal, low-quality gas) and emissions from diesel vehicles.
Nitric oxide (nitric oxide) NO.
Hazard Class -
MPCss - 0.06
MPCmr - 0.4
A colorless gas with a faint sweetish odor, known as “laughing gas” because significant amounts of it have a stimulating effect on the nervous system. Mixed with oxygen, it is used for anesthesia in light operations.
The compound has a positive biological effect. NO is an essential biological conductor capable of causing a large number of positive changes at the cellular level, which leads to improved blood circulation, immune and nervous systems.
Nitrogen oxide is formed when coal, oil and gas burn. It is formed by the interaction of nitrogen N2 and oxygen O2 in the air at high temperatures: the higher the combustion temperature of coal, oil and gas, the more nitrogen oxide is formed. Further, at normal temperatures, NO is oxidized to NO2, which is already a harmful substance.
Nitrogen dioxide (nitrogen dioxide) NO2
Hazard class - 2
MPCss - 0.04
MPCmr - 0.085
At high concentrations it is a brown gas with a suffocating odor. Acts as an acute irritant. However, at the concentrations present in the atmosphere, NO2 is more of a potential irritant and only potentially comparable to chronic lung diseases. However, there was a slight increase in bronchitis in children aged 2-3 years.
Under the influence of solar radiation and in the presence of unburned hydrocarbons, nitrogen oxides react to form photochemical smog.
Often, various nitrogen oxides that are formed during the combustion of any type of fuel are combined into one group “NOx”. However, it is nitrogen dioxide NO2 that poses the greatest danger.
Carbon monoxide CO (carbon monoxide)
Hazard class - 4
MPCss - 0.05
MPCmr - 0.15
Gas is colorless and odorless. Toxic. In acute poisoning, headache, dizziness, nausea, weakness, shortness of breath, rapid pulse. Possible loss of consciousness, convulsions, coma, circulatory and respiratory problems.
With chronic poisoning, headaches, insomnia appear, emotional instability occurs, attention and memory deteriorate. Possible organic damage to the nervous system, vascular spasms
Carbon monoxide is formed as a result of incomplete combustion of carbon in fuel. In particular, when burning carbon or compounds based on it (for example, gasoline) in conditions of lack of oxygen. A similar formation occurs in a stove firebox when the stove damper is closed too early (until the coals have completely burned out). The carbon monoxide formed in this process, due to its toxicity, causes physiological disorders (“fumes”) and even death, hence one of the names - “carbon monoxide”
The main anthropogenic source of CO is currently exhaust gases from internal combustion engines of automobiles. Carbon monoxide is formed during the combustion of hydrocarbon fuels in internal combustion engines at insufficient temperatures or poor adjustment of the air supply system
Carbon dioxide (carbon dioxide) CO2
Colorless gas with a faint sour odor. Carbon dioxide is not toxic, but does not support respiration. High concentrations in the air cause suffocation. Causes hypoxia (lasting up to several days), headaches, dizziness, nausea (concentration 1.5 - 3%). At conc. above 61%, working capacity is lost, drowsiness appears, breathing and cardiac activity are weakened, and life is in danger.
CO2 absorbs infrared rays emitted by the Earth and is one of the greenhouse gases, as a result of which it takes part in the process of global warming
Vanadium pentoxide V2O5.
Hazard class - 1
MPCss - 0.002
Poisonous. Causes irritation of the respiratory tract, pulmonary bleeding, dizziness, disruption of the heart, kidneys, etc. Carcinogen.
The compound is formed in small quantities when fuel oil is burned.
Carbon disulfide (carbon disulfide) CS2, colorless liquid with an unpleasant odor.
Hazard class - 2
MPCss - 0.005
MPCmr - 0.03
Carbon disulfide vapors are poisonous and highly flammable. Acts on the central and peripheral nervous systems, blood vessels, and metabolic processes.
In case of mild poisoning - narcotic effects, dizziness. In case of moderate poisoning, agitation occurs with a possible transition to coma. With chronic intoxication, neurovascular disorders, mental disorders, sleep disorders, etc. occur.
With prolonged poisoning, encephalitis and polyneuritis can occur. Recurrences of seizures with loss of consciousness and respiratory depression may occur. When taken orally, nausea, vomiting, and abdominal pain occur. Upon contact with skin, hyperemia and chemical burns are observed.
Xylene (dimethylbenzene)
Hazard class - 3
MPCss - 0.2
MPCmr - 0.2
Forms explosive vapor-air mixtures.
Causes acute and chronic damage to the hematopoietic organs, dystrophic changes in the liver and kidneys, and upon contact with skin - dermatitis.
Benzene
Hazard class - 2
MPCss - 0.1
MPCmr - 1.5
Colorless volatile liquid with a peculiar mild odor.
Carcinogen.
In acute poisoning, headache, dizziness, nausea, vomiting, agitation followed by a depressed state, rapid pulse, and drop in blood pressure are observed. In severe cases - convulsions, loss of consciousness.
Chronic poisoning is manifested by changes in the blood (impaired bone marrow function), dizziness, general weakness, sleep disturbance, and fatigue. In women - menstrual dysfunction.
Benzpyrene, benz(a)pyrene
Hazard class - 1
MPCss - 0.01
Formed during the combustion of hydrocarbon liquid, solid and gaseous fuels (to a lesser extent during the combustion of gaseous fuels). It can appear in flue gases when burning any fuel with a lack of oxygen in certain combustion zones.
Benz(a)pyrene is the most typical chemical carcinogen in the environment; it is dangerous to humans even at low concentrations, since it has bioaccumulation properties. Being chemically relatively stable, benzo(a)pyrene can migrate for a long time from one object to another. As a result, many environmental objects and processes, which themselves do not have the ability to synthesize benzo(a)pyrene, become its secondary sources. Benz(a)pyrene also has a mutagenic effect.
Toluene (methylbenzene)
Hazard class - 3
MPCss - 0.6
MPCmr - 0.06
Colorless flammable liquid.
The limits of the explosive mixture with air are 1.3 - 7%.
Toluene (methylbenzene) is a highly toxic poison that affects the body’s hematopoietic function, just like its predecessor, benzene. Impaired hematopoiesis manifests itself in cyanosis and hypoxia.
Toluene vapor can penetrate through intact skin and respiratory organs, causing damage to the nervous system (lethargy, disturbances in the functioning of the vestibular apparatus), including irreversible
Chlorine
Hazard class - 2
MPCss - 0.03
MPCmr - 0.1
Yellow-green gas with a pungent irritating odor. Irritates mucous membranes of the eyes and respiratory tract. Primary inflammatory processes are usually accompanied by a secondary infection. Acute poisoning develops almost immediately. When inhaling medium and low concentrations, chest tightness and pain, rapid breathing, pain in the eyes, lacrimation, increased levels of leukocytes in the blood, body temperature, etc. are noted. Bronchopneumonia, pulmonary edema, depression, and convulsions are possible. As long-term consequences, catarrh of the upper respiratory tract, bronchitis, pneumosclerosis, etc. are observed. Activation of tuberculosis is possible. With prolonged inhalation of small concentrations, similar but slowly developing forms of the disease are observed.
Chromium hexavalent
Hazard class - 1
MPCss - 0.0015
MPCmr - 0.0015
Toxic. The initial forms of the disease are manifested by a feeling of dryness and pain in the nose, sore throat, difficulty breathing, cough, etc. With prolonged contact, signs of chronic poisoning develop: headache, weakness, dyspepsia, weight loss, etc. The functions of the stomach, liver and pancreas are impaired. Possible bronchitis, asthma, diffuse pneumosclerosis. When exposed to skin, dermatitis and eczema may develop.
Chromium compounds are carcinogenic.
Soot
Hazard class - 3
MPCss - 0.5
MPCmr - 0.15
Dispersed carbon product of incomplete combustion. Soot particles do not interact with air oxygen and are therefore removed only through coagulation and sedimentation, which occur very slowly. Therefore, to maintain a clean environment, very strict control over soot emissions is needed.
Carcinogen, promotes the development of skin cancer.
Ozone (O3)
Hazard class - 1
MPCss - 0.03
MPCmr - 0.16
Explosive gas of blue color with a sharp characteristic odor. Kills microorganisms, so it is used for water and air purification (ozonation). However, only very small concentrations are permissible in the air because Ozone is extremely toxic (more than carbon monoxide CO).
Lead and its compounds(except tetraethyl lead)
Hazard class - 1
MPCss - 0.0003
It is poisonous, affects the central nervous system, even small doses of lead cause retardation in the development of intelligence in children. Damage to the nervous system is manifested by asthenia, and in severe forms - encephalopathy, paralysis (mainly of the extensors of the hands and fingers), and polyneurism.
With chronic intoxication, damage to the liver, cardiovascular system, and disruption of endocrine functions are possible (for example, in women - miscarriages). Suppression of immunobiological reactivity contributes to increased overall morbidity. Fatal poisoning is also possible.
Lead affects the human nervous system, which leads to decreased
intelligence, causes changes in physical activity, hearing coordination,
affects the cardiovascular system, leading to heart disease.
This has a negative impact on the health of the population and, firstly,
It is the turn of children who are most susceptible to lead poisoning.
Carcinogen, mutagen.
Tetroethyl lead
FOOTWEAR - 0.000003
Flammable
At temperatures above 77°C, explosive vapor/air mixtures may form.
The substance is irritating to eyes, skin, and respiratory tract. The substance may have an effect on the central nervous system, leading to irritability, insomnia, and cardiac disorders. Exposure may cause confusion. Exposure to high concentrations can cause death. Medical supervision is indicated.
With long-term or repeated exposure, it may have a toxic effect on human reproductive function.
Formaldehyde HCOH
Colorless gas with a pungent odor.
Toxic, has a negative effect on genetics, respiratory organs, vision and skin. Has a strong effect on the nervous system. Formaldehyde is listed as a carcinogen.
The substance may have effects on the liver and kidneys, leading to functional impairment
Formaldehyde is used in the production of plastics, and the main part of formaldehyde is used in the production of chipboard and other wood-based materials. In them, phenol-formaldehyde resin makes up 6-18% of the weight of the chips.
Phenol
Phenol is a volatile substance with a characteristic pungent odor. Its vapors are poisonous. In case of contact with the skin, phenol causes painful burns. In acute poisoning, disturbance of respiratory functions and the central nervous system. In case of chronic poisoning - dysfunction of the liver and kidneys
Selenium dioxide
Hazard class - 1
MPCss - 0.05
MPCmr - 0.1
The substance is corrosive to the eyes, skin and respiratory tract. Inhalation may cause pulmonary edema (see Notes). The substance may have effects on the eyes, leading to an allergy-like reaction of the eyelids (red eyes). Medical supervision is indicated.
Repeated or prolonged contact may cause skin sensitization. The substance may cause effects on the respiratory and gastrointestinal tract, central nervous system and liver, resulting in nasopharyngeal irritation, gastrointestinal distress and a persistent garlic odor and liver damage.
Hydrogen sulfide
Hazard class - 2
MPCmr - 0.008
Colorless gas with the smell of rotten eggs.
The substance is irritating to the eyes and respiratory tract. Inhalation of the gas may cause pulmonary edema. Rapid evaporation of the liquid may cause frostbite. The substance may have effects on the central nervous system. Exposure may cause loss of consciousness. Exposure may cause death. Effects may be delayed.
Bromobenzene C6H5Br.
Hazard class - 2
MPCss - 0.03
The substance is irritating to the skin. Ingestion of the liquid may cause aspiration into the lungs with the risk of chemical pneumonia. The substance may have effects on the nervous system
May have effects on the liver and kidneys, leading to functional impairment
Methyl mercaptan CH3SH
Hazard class - 2
MPCmr - 0.0001
Colorless gas with a characteristic odor.
Gas is heavier than air. and can creep along the ground; fire may occur at a distance.
The substance is irritating to the eyes, skin and respiratory tract. Inhalation of the gas may cause pulmonary edema. Rapid evaporation of liquid can cause frostbite. The substance may have effects on the central nervous system, leading to respiratory failure. High dose exposure can cause death.
Due to its strong, unpleasant odor, methyl mercaptan is used to add to harmful, odorless gases to detect leaks.
Nitrobenzene
Hazard class - 4
MPCss - 0.004
MPCmr - 0.2
The substance may have an effect on blood cells, leading to the formation of methemoglobin. Exposure may cause confusion. Effects may be delayed.
With prolonged exposure, it may have an effect on the hematopoietic organs and the liver.
Ammonia
Ammonia NH3, hydrogen nitride (smell of ammonia), almost twice as light as air
Hazard class - 2
MPCss - 0.004
MPCmr - 0.2
A colorless gas with a sharp suffocating odor and acrid taste.
Toxic, severely irritates mucous membranes.
Acute ammonia poisoning affects the eyes and respiratory tract and can be fatal at high concentrations. Causes severe coughing, suffocation, and with a high concentration of vapors - agitation, delirium. Upon contact with skin - burning pain, swelling, burn with blisters. In case of chronic poisoning, indigestion, catarrh of the upper respiratory tract, and hearing loss are observed.
A mixture of ammonia and air is explosive.
Environmental problems are becoming increasingly acute for modern humanity. A particularly serious issue is the quality of air, which is polluted by exhaust gases and emissions from industrial enterprises. To meet the enemy fully armed, you should familiarize yourself with the maximum permissible concentrations of harmful substances in the air.
Maximum concentrations of harmful substances in atmospheric air
What is MPC? MPC is the maximum permissible concentration of chemical elements and their compounds in the air, which does not cause negative consequences in living organisms. Standards for maximum permissible concentrations of harmful substances are approved by law and controlled by sanitary and epidemiological services (in Russia - Rospotrebnadzor) using toxicological studies. The maximum permissible concentration for each substance hazardous to health is included in GOSTs, compliance with which is mandatory. If any enterprise violates the MPC norms, it will be fined or even closed down. The maximum permissible concentration is set for people who are most susceptible to the influence of chemicals (children, elderly people, people with respiratory diseases, etc.). The MPC value for air is measured in mg/m3; there is also a maximum permissible concentration for water, soil and food.
Maximum concentration limits for harmful substances in atmospheric air vary:
- MPC MR – maximum single concentration of a substance. It should not affect living organisms for 20–30 minutes.
- MPC SS – average daily concentration. This maximum permissible concentration should not have a negative impact on living organisms for an indefinitely long time.
Hazard classes of substances
Based on the degree of impact on the body, harmful substances are divided into four hazard classes. Each hazard class has its own maximum permissible concentration. The following hazard classes of substances in atmospheric air are distinguished:
- extremely dangerous substances (maximum concentration limit less than 0.1 mg/m3);
- highly hazardous substances (MPC 0.1–1 mg/m3);
- moderately hazardous substances (MPC 1.1–10 mg/m3);
- low-hazard substances (maximum permissible concentration more than 10 mg/m3).
There is also a classification of harmful substances according to their effect on a living organism. Moreover, some substances belong to several classes at once:
- Generally toxic – substances that cause poisoning of the body as a whole. When exposed to them, convulsions, nervous system disorders, and paralysis are observed.
- Irritants – substances that affect the skin, mucous membrane of the respiratory tract, lungs, eyes, nasopharynx. Long-term exposure leads to respiratory problems, intoxication and death.
- Sensitizers are chemicals that cause an allergic reaction.
- Carcinogens are one of the most dangerous groups of substances that provoke the occurrence of cancer.
- Mutagens are substances that change a person’s genotype. They reduce the body's resistance to disease, cause early aging and can affect the health of the offspring.
- Affecting reproductive health - substances that cause developmental abnormalities in the offspring (not necessarily in the first generation).
Below is a table of the maximum permissible concentrations for some harmful substances in atmospheric air, established in the Russian Federation:
Carbon monoxide (CO)
Another name for carbon monoxide, carbon monoxide, is familiar to us from an early age. It is often found in everyday life - for example, CO is released due to malfunctions of gas water heaters and kitchen stoves. For poisoning with this gas, a very small concentration is needed. Carbon monoxide is colorless and odorless, which makes it even more dangerous. Intoxication occurs rapidly; a person can lose consciousness in a matter of seconds. Despite the fact that the hazard class of carbon monoxide is fourth, its exposure leads to death in just a few minutes. If you feel difficulty breathing, headache, lack of concentration, decreased hearing and vision, you must, if possible, open all windows and doors and leave the room as quickly as possible.
Ammonia (NH3)
Ammonia is a colorless gas with a sharp, pungent odor. It is known to most as a ten percent aqueous solution - ammonia. Although inhaling ammonia vapor has a stimulating effect and helps with fainting, you should be careful with this gas. Ammonia irritates the mucous membrane of the eyes, causes suffocation, and in high concentrations leads to corneal burns and blindness, affects the nervous system to the point of irreversible changes, reduces the cognitive functions of the brain, and provokes hallucinations.
Xylene (C8H10)
Xylene belongs to the third class of danger; it can cause acute and chronic damage to the hematopoietic organs. Xylene is a colorless liquid, but with a characteristic odor, which is used as an organic solvent for the manufacture of plastics, varnishes, paints, and construction adhesives. In small concentrations, xylene does not harm humans in any way, but with prolonged inhalation of xylene vapors, drug addiction appears. Xylene also affects the nervous system and causes irritation to the skin and mucous membranes of the eyes.
Nitric oxide (NO)
Nitric oxide is a toxic, colorless gas. It does not irritate the respiratory tract, so it is difficult for a person to feel it. NO reacts with hemoglobin and forms methemoglobin, which blocks the airways and causes oxygen deprivation. When interacting with oxygen, the gas turns into nitrogen dioxide (NO2).
Sulfur dioxide (SO2)
Sulfur dioxide, or sulfur dioxide, has a characteristic odor similar to that of a burning match. Inhaling SO2, even in small concentrations, can lead to inflammation of the respiratory tract, causing coughing, runny nose and hoarseness. Long-term exposure provokes speech defects, a feeling of lack of air, and pulmonary edema. Damage to lung tissue is also possible, but this does not appear until several days after exposure. People with diseases of the respiratory system, for example, are most susceptible to the effects of SO2.
Toluene (C7H8)
Toluene enters the human body not only through the respiratory system, but also through the skin. Symptoms of toluene poisoning are irritation of the mucous membrane of the eyes, lethargy, disruption of the vestibular apparatus, hallucinations. Toluene is also extremely fire hazardous and has a narcotic effect. Until 1998, it was part of Moment glue and is still contained in some varnish and paint solvents.
Hydrogen sulfide (H2S)
Hydrogen sulfide is a colorless gas with an odor reminiscent of rotten eggs. Being highly toxic, H2S primarily affects the nervous system, causing severe headaches, seizures and can lead to coma. The lethal concentration of hydrogen sulfide is approximately 1,000 mg/m3. At a concentration of 6 mg/m3, headaches, dizziness and nausea begin.
Chlorine (Cl2)
Chlorine gas has a yellow-green color and a pungent, irritating odor. Some of the first symptoms of chlorine poisoning are red eyes, coughing attacks, chest pain, and increased body temperature. Possible development of bronchopneumonia and bronchitis. Being a strong carcinogen, chlorine provokes the occurrence of cancer and tuberculosis. At high concentrations, death can occur after a few breaths.
Formaldehyde (HCOH)
The content in the air is especially high in large cities, since it is a product of combustion of vehicle fuel. Formaldehyde emissions also occur in chemical, tanning and wood processing plants. It negatively affects genetic material, reproductive and respiratory systems, liver, and kidneys. Poisoning begins with increasing damage to the nervous system - with dizziness, feelings of fear, trembling, uneven gait, etc. Formaldehyde is officially recognized as a carcinogen, but it also has allergenic, mutagenic and sensitizing effects.
Nitrogen dioxide (NO2)
Nitrogen dioxide is a poisonous gas of red-brown color with a characteristic pungent odor. It is formed as a result of the combustion of automobile fuel, the activities of thermal power plants and industrial enterprises. At the initial stage of exposure, nitrogen dioxide disrupts the functioning of the upper respiratory tract, and subsequently can cause bronchitis, inflammation or pulmonary edema. This gas is most dangerous for people suffering from bronchial asthma and other pulmonary diseases. Because of the color of nitrogen dioxide, its emissions are called “foxtail.” This gas is associated with the fox not only by its color, but also by its cunning: in order to “hide” from people, it impairs the sense of smell and vision, so it is not so easy to detect.
Phenol (C6H5OH)
Phenol is one of the industrial pollutants that is harmful to animals and humans. When inhaling phenol vapors, loss of strength, nausea, and dizziness occur. Phenol negatively affects the nervous and respiratory systems, as well as the kidneys, liver, etc. The use of phenol often leads to disastrous consequences. In the seventies in the USSR it was used in the construction of residential buildings. People who lived in “phenolic houses” complained of poor health, allergies, cancer and other ailments. Although phenol-formaldehyde resins are used in furniture, building materials and much more, unscrupulous manufacturers may exceed the permitted limit or use substandard chemicals.
Benzene (C6H6)
Benzene is a dangerous carcinogen. In case of benzene vapor poisoning, a person experiences headache, nausea, mood swings, heart rhythm disturbances, and sometimes fainting. Constant exposure to benzene on the body is manifested by fatigue, bone marrow dysfunction, leukemia, and anemia. Often the first sign of benzene poisoning is euphoria, since inhaling its vapors has a narcotic effect. This chemical compound is part of gasoline and is used to produce plastics, dyes, and synthetic rubber.
Ozone (O3)
This gas, which has a characteristic odor and is blue in color at high concentrations, protects us from ultraviolet radiation from the sun. Ozone is a natural antiseptic and disinfects water and air. Another thing that speaks in favor of ozone is that the air after a thunderstorm, saturated with ozone, seems fresh and invigorating to us. Unfortunately, ozone causes extremely unpleasant consequences. It aggravates allergies, aggravates heart disease, reduces immunity and causes breathing problems. Ozone acts slowly, but is extremely harmful in the long term - this gas is especially dangerous for children, the elderly and asthmatics.