What is a chemical substance examples. The most important chemicals used in everyday life. Manufacturers and suppliers of industrial chemicals

It's impossible to imagine modern life and chemical-free production. When in close contact with them, the human body has some effect. It should be noted that there are also compounds that will manifest their influence after a certain period of time. In this article we will try to understand what chemical factors exist, the hazard classes of harmful substances, and also how they affect the human body.

Human use of chemicals

Several million are now known chemical compounds, and most of them are used by people in various industries. If we consider the hazard classes of chemicals from the point of view of application, the list may look like this:

1. Toxic substances used in industry. These include: dyes (aniline), among solvents this is dichloroethane, for example.
2. Pesticides are widely used in the agricultural industry.
3. Chemical compounds that are used in everyday life: hygiene products, for sanitary treatment.
4. Toxic substances of natural origin, such as plant and animal poisons.
5. Poisonous substances: mustard gas, phosgene and others.

Various classes of hazardous chemicals can enter the body through the organs respiratory system, skin or mucous membranes. Substances can have their effect Negative influence selectively, that is, on a specific organ system. For example, lead affects the human reproductive system, and nitrogen oxides can cause swelling of the lung tissue.

Toxic effects of chemicals

If we consider the hazard class of chemicals, GOST distinguishes several groups. Each also has its own divisions.

There are five classes depending on the toxic effects and the average lethal dose.

1. The first hazard class includes compounds that require very little to damage the body. For example, when ingested, this amount is 50 mg per kilogram of human weight.
2. Class 2 includes substances whose concentrations may be higher to cause toxic effects. This can be from 5 to 50 mg per m3 if exposure occurs through the skin or gastrointestinal tract.
3. Classes 3 and 4 include compounds that require more than the first two classes and usually amount to up to 5000 units.
4. The fifth class includes substances that cause deep toxic damage.

Chemicals and the organ of vision

If we take into account the effect of chemicals on the organ of vision, the following classes are distinguished:

1. The first class includes compounds that lead to irreversible changes in the ocular apparatus, and all this ends in visual impairment.
2. The second class contains substances that cause pathological changes in vision, but they can subside within a few weeks.

Exposure to chemicals on the skin

There is another classification, it identifies classes of chemicals that have a negative effect on the skin. When dividing compounds, two criteria were used. Considering the first, three classes are distinguished:

• The first group includes substances that lead to visible skin necrosis.
• The second class includes substances that cause reversible damage. In about two weeks, the skin is restored.
• Substances in class three cause only minor skin irritation, which usually goes away within a couple of days.

The second classification criterion is used in cases where there is insufficient data to classify substances into the first three groups.

Impact of chemical compounds on the environment

According to GOST, there is also a classification that takes into account the impact of chemical compounds on the environment. This group includes the following categories of substances:

• Detrimental to the ozone layer.
• Having an acute toxic effect on the aquatic environment.
• Substances that have a gradual toxic effect on the inhabitants of water resources.

All these harmful compounds can be further divided into categories based on their harmfulness. A concentration of 0.1 mg/l is sufficient to produce a toxic effect.

Classification of chemicals by hazard classes

In the huge variety of known substances, not all are equally dangerous to the human body. The following classes are distinguished:

1. The first class includes extremely dangerous substances and compounds. To cause death, 15 mg of the substance per kilogram of a person’s weight will be sufficient to enter the stomach. Examples include the following: potassium cyanide, mercury, nicotine and others.
2. The second class includes highly hazardous substances. The lethal dosage ranges from 15 to 150 mg per kilogram of body weight, taking into account the properties of the substance. These compounds have negative impact not only per person, but also per person surrounding nature. These include: arsenic, lithium, lead, chloroform.
3. Moderately hazardous is the third class of hazard of chemicals. For death, 500-2500 mg/kg is sufficient. When ingested, the lethal dose is 150-5000 mg/kg body weight. This class includes: gasoline, aluminum and manganese compounds. Since many substances of this class are often used in Everyday life, then you cannot handle them carelessly.
4. Low-hazard substances are the most harmless, as they are distinguished by their low toxicity and danger. These substances often surround us, for example, ammonia can be found in every first aid kit, kerosene is used in lamps, ethanol is used in medicine and is found in alcoholic beverages.

No matter how many hazard classes of chemicals there are, it is important to treat them all with extreme caution and follow all safety precautions when working with them.

Classification of substances according to their effects on the body

All available chemical substances and the compounds differ from each other not only in the degree of toxicity, but also in the nature of the effect on humans.

Depending on their hazard class, all substances are assigned a specific color.

1. Extremely hazardous substances are indicated in red.
2. A high degree of danger is marked in orange.
3. Moderately dangerous are yellow in color.
4. Substances that are classified as low-hazard are indicated in green.

Classification of substances in terms of toxic effects

The toxicity of chemicals is completely different, and the hazard classes in this regard are as follows:

1. Substances that have a nerve paralytic effect include: insecticides, nicotine, sarin.
2. Compounds that cause inflammatory processes and necrotic changes in combination with general toxic effects. Examples include: vinegar essence, arsenic, mercury.
3. Compounds that cause convulsions, coma, cerebral edema, that is, they have a general toxic effect. These include: hydrocyanic acid, carbon monoxide, alcohol.
4. Asphyxiants (fosten, nitrogen oxides).
5. Substances that cause tearing and irritation of mucous membranes. An example is: vapors of acids and alkalis.
6. Substances and compounds that affect the psyche. This includes narcotic substances, atropine and others.

If you are going to use or come into contact with these substances, take special care.

International classification

We looked at how many hazard classes of chemicals exist according to GOST, but there is also a division based on international requirements. It represents 9 groups, each of which has its own rules for transportation and storage.

1. Substances that can easily explode or catch fire.
2. The second class includes substances that are flammable, toxic, and chemically unstable.
3. Chemicals in liquid state, which are highly flammable, belong to class 3.
4. Class 4 includes solid substances capable of spontaneous combustion or combustion after external influence.
5. Organic oxidizers belong to class 5, as they are capable of releasing oxygen, which supports combustion.
6. 6th grade is toxic substances, causing severe poisoning or death if vapors are inhaled.
7. The next class is radioactive substances.
8. Corrosive substances are the eighth hazard class.
9. Class 9 included all other substances that were not included in the previous classes, but to some extent may be dangerous.

How to protect yourself from hazardous substances

It is important not only to know the hazard class of chemicals, but also to be able to minimize the degree of impact on human body and nature. To do this, you can use the following methods:

• Place toxic and harmful substances in enterprises as far as possible from workplaces.
• Have a modern and effective system ventilation for removal hazardous substances.
• Use in a timely manner individual means protection.
• Use modern methods purifying water before releasing it into the environment.
• Dilute harmful compounds to acceptable concentrations.

Application of these available methods will maximize the safety of humans and nature from the effects of harmful chemicals.

Let's sum it up

If we summarize all that has been said, we can not only highlight the hazard class of chemical substances, but also note following types exposure to harmful compounds:

1. Irritating effect, if they come into contact with the skin, they cause redness, for example, fluorine, phosphorus, etc.
2. The cauterizing effect of the substance can cause burns of varying degrees. These include: ammonia, hydrochloric acid.
3. Asphyxiants can cause asphyxia and death. Phosgene and chloropicrin have this effect.
4. Substances with toxic effects can cause poisoning of varying severity. These include: hydrogen sulfide, hydrocyanic acid, ethylene oxide and others.
5. Mutagenic substances can cause mutations.
6. Carcinogenic exposure leads to the development of cancer.

Some classifications also identify narcotic substances, which, once inside the body, cause addiction and gradual poisoning of the body.

So we got acquainted with the variety of chemical substances that surround us almost everywhere. It is almost impossible to imagine without chemistry modern industry and production. But in order not to cause harm to your body during interaction with harmful substances, you must take special care and know the rules of storage and transportation.

Abbreviations:

T kip. - boiling temperature,

T pl. - melting temperature.

Adipic acid (CH 2) 4 (COOH) 2- colorless crystals, soluble in water. T. pl. 153 °C. Forms salts - adipates. Used to remove scale.

Nitric acid HNO 3- a colorless liquid with a pungent odor, unlimitedly soluble in water. T. kip. 82.6 °C. Strong acid, causes deep burns and must be handled with care. Forms salts - nitrates.

Potassium alum KAl(SO 4) 2 .12H 2 O- double salt, colorless crystalline substance, highly soluble in water. T pl. 92°C.

Amyl acetate CH 3 SOOS 5 H 11 (amyl ester of acetic acid)- a colorless liquid with a fruity odor, an organic solvent and fragrance.

Amino acids— organic matter, in the molecules of which there are carboxyl groups COOH and amino groups NH 2. They are part of proteins.

Ammonia NH- a colorless gas with a pungent odor, highly soluble in water, forms ammonia hydrate NH 3 .H 2 O.

Ammonium nitrate, cm. . Aniline (aminobenzene, phenylamine) C 6 H 5 NH 2- a viscous, colorless liquid that darkens in light and air. Insoluble in water, soluble in ethyl alcohol and diethyl ether. T kip. 184 °C. Poisonous.

Arachidonic acid C 19 H 31 COOH- an unsaturated carboxylic acid with four double bonds in the molecule, colorless liquid. T kip. 160-165 °C. Included in vegetable fats.

Ascorbic acid (vitamin C), organic matter complex structure- colorless crystals, sensitive to heat. Participates in the redox processes of a living organism.

Squirrels- biopolymers consisting of amino acid residues. They play a vital role in life processes.

Petrol— a mixture of light hydrocarbons; obtained during oil refining. T kip. from 30 to 200 °C. Fuel and organic solvent.

Benzoic acid C 6 H 5 COOH- a colorless crystalline substance, poorly soluble in water. Above 100 °C it decomposes.

Benzene C 6 H 6- aromatic hydrocarbon. T kip. 80 °C. Flammable, poisonous.

Betaine (trimethylglycine) (CH 3) 3 N + CH 2 COO- an organic substance, highly soluble in water, found in plants (for example, beets).

Boric acid B(OH) 3- a colorless crystalline substance, slightly soluble in water, a weak acid.

Sodium bromate NaBrO 3- colorless crystals, soluble in water. Melts at 384 °C with decomposition. In an acidic environment it is a strong oxidizing agent.

Wax- fat-like amorphous substance vegetable origin, mixture esters fatty acids. Melts in the range of 40-90 °C.

Galactose C 6 H 12 O 6 .H 2 O- carbohydrate, monosaccharide, colorless crystalline substance, soluble in water.

Sodium hypochlorite (trihydrate) NaClO .3H 2 O- a greenish-yellow crystalline substance, highly soluble in water. T. pl. 26 °C, above 40 °C decomposes, explodes in the presence of organic substances. Bleach.

Glycerol CH(OH)(CH 2 OH) 2- a colorless viscous liquid, unlimitedly soluble in water and absorbing moisture from the air, trihydric alcohol. It is part of fats in the form of lipids - triglycerides (esters of glycerol with organic acids).

Glucose (grape sugar) C 6 H 12 O 6- carbohydrate, monosaccharide, colorless crystalline substance, highly soluble in water. T pl. 146 °C. Contained in the juice of all plants and in the blood of humans and animals.

Calcium gluconate Ca[CH 2 OH (CHOH) 4 COO] 2.H 2 O (monohydrate)- white crystalline powder, slightly soluble in cold water, practically insoluble in ethyl alcohol.

Gluconic (sugar) acid CH 2 (OH)(CHOH) 4 COOH- a colorless crystalline substance, soluble in water, obtained from the oxidation of glucose. Forms salts - gluconates.

Double superphosphate (calcium dihydrogen orthophosphate monohydrate) Ca(H 2 PO 4) 2 .H 2 O — White powder, soluble in water.

Dibutyl phthalate C 6 H 4 (SOOC 4 H 9) 2 (butyl ester of phthalic acid)- colorless liquid with a fruity odor, slightly soluble in water. Organic solvent and repellent.

Ammonium dihydrogen orthophosphate NH 4 H 2 PO 4- a colorless crystalline substance, soluble in water. Fertilizer (diammo-phos).

Dimetzphthalate C 6 H 4 (COOCH 3) 2 (phthalic acid methyl ester)- colorless volatile liquid. Organic solvent and repellent.

Ferrous sulfate (ferrous sulfate heptahydrate) F e S O 4 .7H 2 O- greenish crystals, soluble in water. In air it gradually oxidizes.

Iron minium— iron(III) oxide Fe 2 O 3 with impurities. Mineral paint of red-brown color.

Yellow blood salt (potassium hexacyanoferrate (II) trihydrate) K 4 [Fe (CN) 6].3H 2 O- light yellow crystals, soluble in water. In the 18th century It was obtained from slaughterhouse waste, hence the name.

Fatty acid— carboxylic acids containing 13 or more carbon atoms.

Soda Ash, cm. .

Camphor C 10 H 16 O- colorless crystals with a characteristic odor. T pl. 179 °C, easily sublimes when heated. Dissolves in organic solvents, slightly soluble in water.

Rosin- glassy substance yellow color. T pl. 100-140 °C, consists of resin acids - organic substances of cyclic structure. Soluble in organic solvents and acetic acid, insoluble in water.

Ammonium carbonate (NH 4) 2 CO 3- a colorless crystalline substance, highly soluble in water, decomposes when heated.

Kerosene- a mixture of hydrocarbons obtained during oil refining. T kip. 150-300 °C. Fuel and organic solvent.

Red blood salt K 3 [Fe (CN) 6 ] (potassium hexacyanoferrate (III))- red crystals, soluble in water. In the 18th century was obtained from slaughterhouse waste, hence the name.

Starch [C 6 H 10 O 5 ] n- white amorphous powder, polysaccharide. With prolonged contact with water, it swells, turns into a paste, and when heated, forms dextrin. Contained in potatoes, flour, cereals.

Litmus- natural organic substance, acid-base indicator (blue in alkaline, red in acidic environment).

Butyric acid C 3 H 7 COOH- colorless liquid with an unpleasant odor. T kip. 163 °C.

Mercaptans (thioalcohols) — organic compounds containing an SH group, for example, methyl mercaptan CH 3 SH. They have a disgusting smell.

Iron metahydroxide FeO(OH)- brown-brown powder, insoluble in water, the basis of rust.

Sodium metasilicate (nonahydrate) Na 2 SiO 3 .9H 2 O- a colorless substance, highly soluble in water. T pl. 47 °C, above 100 °C loses water. Aqueous solutions (silicate glue, soluble glass) have a highly alkaline reaction due to hydrolysis.

Carbon monoxide (carbon monoxide) CO- a colorless and odorless gas, a strong poison. Formed when incomplete combustion organic substances.

Formic acid HCOOH- a colorless liquid with a pungent odor, infinitely soluble in water, one of the most powerful organic acids. T kip. 100.7 °C. Contained in insect secretions, nettles, and pine needles. Forms salts - formates.

Naphthalene C 10 H 8- a colorless crystalline substance with a pungent characteristic odor, insoluble in water. Sublimes at 50 °C. Poisonous.

Ammonia- 5-10% aqueous ammonia solution.

Unsaturated (unsaturated) fatty acid - fatty acids whose molecules contain one or more double bonds.

Polysaccharides- carbohydrates of complex structure (starch, cellulose, etc.).

Propane C 3 H 8- colorless flammable gas, hydrocarbon.

Propionic acid C 2 H 5 COOH- colorless liquid, soluble in water. T kip. 141 °C. Weak acid, forms salts - propionates.

Simple superphosphate- a mixture of water-soluble calcium dihydrogen orthophosphate Ca(H 2 PO 4) 2.H 2 O and insoluble calcium sulfate CaSO 4.

Resorcinol C 6 H 4 (OH) 2- colorless crystals with a characteristic odor, soluble in water and ethyl alcohol. T pl. 109 - 110 °C

Salicylic acid HOC 6 H 4 COOH- a colorless crystalline substance, slightly soluble in cold water, highly soluble in ethyl alcohol. T pl. 160 °C.

Sucrose C 12 H 22 O 11- a colorless crystalline substance, highly soluble in water. T pl. 185 °C.

Lead lead Pb 3 O 4- a finely crystalline substance of red color, insoluble in water. Strong oxidizing agent. Pigment. Poisonous.

Sulfur S 8- a yellow crystalline substance, insoluble in water. T pl. 119.3 °C.

Sulfuric acid H 2 SO 4- a colorless, odorless, oily liquid, infinitely soluble in water (with strong heating). T kip. 338 °C. A strong acid, a caustic substance, forms salts - sulfates and hydrosulfates.

Sulfur color- finely ground sulfur powder.

Hydrogen sulfide H 2 S- colorless gas with odor rotten eggs, soluble in water, is formed during the decomposition of proteins. Strong reducing agent. Poisonous.

Silica gel (silicon dioxide polyhydrate) n SiO2 m H2O- colorless granules, insoluble in water. Good adsorbent (absorber) of moisture.

Carbon tetrachloride (carbon tetrachloride) CCl 4- colorless liquid, insoluble in water. T kip. 77 °C. Solvent. Poisonous.

Tetraethyl lead Pb(C 2 H 5) 4- colorless flammable liquid. Additive to automobile fuel(in amounts up to 0.08%). Poisonous.

Sodium tripolyphosphate Na 3 P 3 O 9- colorless solid, unlimitedly soluble in water, aqueous solutions are alkaline due to hydrolysis.

Hydrocarbons- organic compounds of the composition C x H y (for example, propane C 3 H 8, benzene C 6 H 6).

Carbonic acid H 2 CO 3- a weak acid, exists only in aqueous solution, forms salts - carbonates and bicarbonates.

Acetic acid CH 3 COOH- colorless liquid. Crystallizes at 17°C. Unlimitedly soluble in water and ethyl alcohol. "Ice" acetic acid contains 99.8% CH 3 COOH.

Acetaldehyde, cm. .

Fructose (fruit sugar) C 6 H 12 O 6 .H 2 O- monosaccharide, colorless crystalline substance, soluble in water. T pl. about 100 °C. One and a half times sweeter than sucrose, found in fruits, flower nectar, and honey.

Hydrogen fluoride HF- a colorless gas with a suffocating odor, highly soluble in water with the formation of hydrofluoric acid.

Citrates- salts of citric acid.

Oxalic acid (dihydrate) H 2 C 2 O 4 .2H 2 O- a colorless crystalline substance, soluble in water. Sublimes at 125 °C. Contained in sorrel, spinach, sorrel in the form of potassium salt.

Ethyl acetate (ethyl acetate) CH 3 COOC 2 H 5- a colorless liquid with a fruity odor, slightly soluble in water. T kip. 77 °C.

Ethylene glycol C 2 H 4 (OH) 2 - colorless viscous liquid, unlimitedly soluble in water. T pl. 12.3 °C, boiling point 197.8 °C. Poisonous.

Ethyl alcohol (ethanol, wine alcohol) C 2 H 5 OH- colorless liquid, unlimitedly soluble in water. T kip. 78°C. Used as a solvent and preservative. In large doses it is a strong poison.

Ethers— organic substances, including fragments of alcohols or alcohols and acids, connected through an oxygen atom.

Malic (hydroxysuccinic) acid CH(OH)CH2 (COOH)2- a colorless crystalline substance, soluble in water. T pl. 100 °C.

Succinic acid (CH 2) 2 (COOH) 2- a colorless crystalline substance, soluble in water. T pl. 183 °C. Forms salts - succinates.

The elementary particles of physical matter on our planet are atoms. They can exist in a free form only under very high temperatures. Under normal conditions elementary particles strive to unite with each other using chemical bonds: ionic, metallic, covalent polar or nonpolar. In this way, substances are formed, examples of which we will consider in our article.

Simple substances

The processes of interaction between atoms of the same chemical element result in the formation of chemical substances called simple ones. Thus, coal is formed only by carbon atoms, hydrogen gas is formed by hydrogen atoms, and liquid mercury consists of mercury particles. The concept of a simple substance does not need to be identified with the concept of a chemical element. For example, carbon dioxide does not consist of the simple substances carbon and oxygen, but of the elements carbon and oxygen. Conventionally, compounds consisting of atoms of the same element can be divided into metals and non-metals. Let's look at some examples of the chemical properties of such simple substances.

Metals

Based on the position of the metal element in the periodic table, the following groups can be distinguished: active metals, elements of the main subgroups of the third - eighth groups, metals of the secondary subgroups of the fourth - seventh groups, as well as lanthanides and actinides. Metals - simple substances, examples of which we will give below, have the following general properties: thermal and electrical conductivity, metallic luster, ductility and malleability. Such characteristics are inherent in iron, aluminum, copper and others. With an increase in the serial number in periods, the boiling and melting temperatures, as well as hardness, increase metal elements. This is explained by the compression of their atoms, that is, a decrease in the radius, as well as the accumulation of electrons. All parameters of metals are determined internal structure crystal lattice of these compounds. Below we will consider chemical reactions, and also give examples of the properties of substances related to metals.

Features of chemical reactions

All metals with an oxidation state of 0 exhibit only reducing properties. Alkaline and alkaline earth elements react with water to form chemically aggressive bases - alkalis:

• 2Na+2H 2 0=2NaOH+H 2

A typical reaction of metals is oxidation. As a result of combination with oxygen atoms, substances of the oxide class arise:

• Zn+O 2 =ZnO

These are binary compounds related to complex substances. Examples of basic oxides are the oxides of sodium Na 2 O, copper CuO, and calcium CaO. They are capable of interacting with acids, as a result salt and water are found in products:

• MgO+2HCl=MgCl 2 +H 2 O

Substances of the classes acids, bases, and salts belong to complex compounds and exhibit diverse chemical properties. For example, a neutralization reaction occurs between hydroxides and acids, leading to the appearance of salt and water. The composition of the salts will depend on the concentration of the reagents: for example, when there is an excess of acid in the reacting mixture, acidic salts are obtained, for example, NaHCO 3 - sodium bicarbonate, and a high concentration of alkali causes the formation of basic salts, such as Al(OH) 2 Cl - aluminum dihydroxychloride.

Nonmetals

The most important non-metallic elements are found in the subgroups of nitrogen, carbon, and also belong to the groups of halogens and chalcogens periodic table. Let us give examples of substances related to non-metals: sulfur, oxygen, nitrogen, chlorine. All of them physical features opposite to the properties of metals. They don't spend electricity, do not transmit heat rays well, and have low hardness. When interacting with oxygen, nonmetals form complex compounds - acid oxides. The latter, reacting with acids, give acids:

• H 2 O+CO 2 → H 2 CO 3

A typical reaction characteristic of acidic oxides is interaction with alkalis, leading to the appearance of salt and water.

The chemical activity of non-metals increases during the period, this is due to an increase in the ability of their atoms to attract electrons from other chemical elements. In groups we observe the opposite phenomenon: non-metallic properties weaken due to inflation of the volume of the atom due to the addition of new energy levels.

So, we looked at the types of chemical substances, examples illustrating their properties, and position in the periodic table.

Chemicals, by definition, pose some degree of danger if used incorrectly and without proper precautions. To know exactly what you can expect from a particular substance, there are classifications of chemicals according to the degree of danger.

According to established requirements GOST 12.1.007-76 chemicals are divided into four classes on the level of toxicity and their effects on living organisms, in particular on humans and animals. The hazard class depends on factors such as MPC, KVIO, average lethal dose when applied to the skin or ingested. Another document regulating the level of danger of chemicals is SanPiN 2.1.4. 1074-01.

Classification of chemically hazardous substances

1st hazard class

1st class of danger. These are extremely dangerous substances, the maximum permissible concentration of which is less than 0.1. The inhaled dose to cause death is less than 15 mg/kg of any substance in this toxicity class. Only 100 milligrams or less of such a substance per kilogram is enough to cause death if it comes into contact with the skin. The above doses during the experiments led to the death of more than half of the experimental animals. In the tables they are designated as LD 50 (oral) and LD 50 (dermal).

The next, most important, indicator of the toxicity and danger of a substance is its MPC, or maximum permissible concentration. The maximum permissible concentration for extremely dangerous substances in the atmosphere is about 0.1 milligrams per cubic meter. The coefficient of possibility of inhalation poisoning is more than 300, the zone of acute action is 6.0, the zone of chronic action is 10, the zone of biological action is more than 1000.