Harmful substance is a substance that, when contacting a person's organism, can cause diseases or deviations in a state of health, detectable modern methods It is both directly in the process of contact with the substance and in the distant terms of life of the present and subsequent generations.
The substance is harmful - 1. The chemical compound, which, when contacting the human body, can cause arbitrary injuries, professional diseases or deflection in a state of health (GOST 12.1.007-76). 2. Chemical substance that causes a violation in the growth, development or state of health of the organisms can also affect these indicators over time, including in the chain of generations.
According to GOST 12.1.001-89, all harmful substances according to the degree of impact on the human body are divided into the following classes:
Extremely dangerous.
Highly hazard.
Moderately dangerous.
Low hazard.
The danger is established depending on the magnitude of the MPC, the average lethal dose and the zone of acute or chronic action.
The irrational use of chemicals, synthetic materials adversely affects the health of working. Harmful substance (industrial poison), falling into the human body during his professional activity, causes pathological changes. The main sources of air pollution production premises Harmful substances may be raw materials, components and finished products. Diseases arising from the effects of these substances are called professional poisoning (intoxication).
Toxic substances are entered into the human body through the respiratory tract (inhalation penetration), the gastrointestinal tract and the skin. The degree of poisoning depends on their aggregate state and on the nature of the technological process (heating of the substance, grinding, etc.). The main way of receipt toxic substances are lungs. In addition to acute and professional chronic intoxication, industrial poisons may cause a decrease in the body's stability and an increased overall incidence.
Poison properties can show all substances, even such as a cooking salt in large doses or oxygen at elevated pressure. However, it is customary to belong to poisons that their harmful effects exhibit under normal conditions and in relatively small quantities.
The industrial poisons include a large group of chemicals and compounds, which in the form of raw materials, intermediate or finished products are found in production.
The toxic effect of harmful substances is characterized by indices of toxicometry, in accordance with which substances are classified on extremely toxic, highly toxic, moderately toxic and small-toxic. The effect of toxic action of various substances depends on the amount of substance that has fallen into the body, its physical properties, the duration of the receipt, the chemical of interaction with biological media (blood, enzymes). In addition, the effect depends on gender, age, individual sensitivity, ways to enter and eliminate, distribution in the body, as well as meteorological conditions and others related factors ambient.
Indicators of toxicometry and criteria for toxicity of harmful substances are quantitative indicators of toxicity and danger of harmful substances. The toxic effect under the action of various doses and the concentrations of poisons can manifest itself with functional and structural (pathorphological) changes or death of the body. In the first case, toxicity is made to express in the form of existing, threshold and inactive doses and concentrations.
Table 7.1 Toxicological classification of harmful substances
|
General toxic impact |
Toxic substances |
|
Neuro-paralytic action (bronchospasm, chopping, cramps and paralysis) |
Phosporganic insecticides (chlorophos, carboofos, nicotine, sv, etc.) |
|
Skin-resorbative action (local inflammatory and necrotic changes in combination with general oxic resorptive phenomena) |
Dichloroethane, Hexochlororan, acetic essence, arsenic and its compounds, mercury (Sumull) |
|
General oxic effect (hypoxic convulsions, coma, brain edema, paralysis) |
Sinyl Acid and its derivatives, carbon monoxide, alcohol and its surrogates, |
|
Rejuving effect (toxic edema lungs) |
Nitrogen oxides, s |
|
Tear and irritant action (irritation of outer mucous membranes) |
Pairs of strong acids and alkalis, chlorpicrin, s |
|
Psychotic action (violation of mental activity, consciousness) |
Drugs, Atropine |
In production, as a rule, during the working day, the concentration of harmful substances is not permanent. They either grow by the end of the shift, declining for the lunch break, or sharply fluctuate, putting an intermittent (non-permanent) action on humans, which in many cases is harmful than continuous, since frequent and sharp vibrations of the stimulus lead to a breakdown of adaptation formation.
Currently, about 7 million chemicals and compounds are known (hereinafter referred to as the substance), of which 60 thousand are used in human activity. In the international market, 500-1000 new chemical compounds and mixtures annually appear.
Harmful a substance that, when contacting the human body, can cause injuries, diseases or deviations in a state of health, detected by modern methods, both in the process of contact with it and in the long-term deadlines of the present and subsequent generations are called.
Table 3.2.
Chemicals (organic, inorganic, elementorganic) depending on their practical use are classified:
- - on industrial poices used in production: for example, organic solvents (dichloroethane), fuel (propane, butane), dyes (aniline);
- - Yadochimikati used in agriculture: pesticides (hexahloran), insecticides (carboofos), etc.;
- - medicinal products;
- - household chemicals used in the form of food additives (acetic acid), sanitation, personal hygiene, cosmetics, etc.;
- - biological vegetable and animals of the poisons, which are contained in plants and mushrooms (aconite, cicut), in animals and insects (snakes, bees, scorpions);
- - poisoning substances (s): ZARIN, IPRIT, phosgene, etc. Poison properties can show all substances, even such as a salt in large doses or oxygen at elevated pressure. However, it is customary to identify only those substances that their harmful effects exhibit under normal conditions and in relatively small quantities.
The industrial poisons include a large group of chemicals and compounds, which in the form of raw materials, intermediate or finished products are found in production.
In the body, industrial chemicals can penetrate through respiratory organs, gastrointestinal tract and intact skin. However, the main ways are lungs. In addition to acute and chronic professional intoxication, industrial poisons can cause a decrease in the body's stability and increasing the overall morbidity.
Household poisonings most often occur when poison in the gastrointestinal tract (keriformicates, household chemicals, medicinal substances). Acute poisoning and diseases are possible when entering the poison directly into the blood, for example, in the bite of snakes, insects and injecting medicinal substances.
The toxic effect of harmful substances is characterized by indices of toxicometry, in accordance with which substances are classified on extremely toxic, highly toxic, moderately toxic and small-toxic. The effect of the toxic effect of various substances depends on the amount of substance that has fallen into the body, its physical properties, the duration of the receipt, the chemical of interaction with biological media (blood, enzymes). In addition, it depends on gender, age, individual sensitivity, ways to enter and eliminate, distribution in the body, as well as meteorological conditions and other concomitant environmental factors.
The total toxicological classification of harmful substances is given in Table. 3.3.
Table 3.3. Toxicological classification of harmful substances
|
General toxic impact |
Toxic substances |
|
Nerivo-paralytic action (bronchospasm, suffocation, cramps and paralysis) Skin-resorbative action (local inflammatory and necrotic changes in combination with general oxic resorptive phenomena) General oxic effect (hypoxic convulsions, coma, brain swelling, paralysis) Suffocating effect (toxic pulmonary edema) tear and irritant action (irritation of outer mucous membranes) Psychotic action (mental violation) |
Phosphorganic insecticides (chlorophos, carboofos, nicotine, oh, etc.) Dichloroethane, Hexakhloran, acetic essence, arsenic and its compounds, mercury (SUMMA) Sinyl Acid and its derivatives, carbon monoxide, alcohol and its surrogates, oh oxides of nitrogen, s Pairs of strong acids and alkalis, chlorpicrin, s Drugs, Atropine |
Poons along with general possess electoral toxicity, i.e. They represent the greatest danger to a certain organ or system of the body. In electoral toxicity, poisons are distinguished:
- - cardiac with predominant cardiotoxic effect; This group includes many drugs, vegetable poisons, metals salts (barium, potassium, cobalt, cadmium);
- - Hepatic, among which chlorinated carbohydrates, poisons contained in mushrooms, phenols, and aldehydes should be highlighted.
- - blood, which includes aniline and its derivatives, nitrites, arsenic hydrogen;
- - pulmonary, in which nitrogen oxides, ozone, phosgene, etc.
The study of the biological effect of chemicals per person shows that their harmful effects always begins with a certain threshold concentration.
For a quantitative assessment of the harmful effects on a person of a chemical in industrial toxicology, indicators characterizing the degree of its toxicity are used.
Average deadly concentration in the air LC50 is a concentration of a substance that causes the death of 50% of animals with a two-four-hour inhalation effect on mice or rats.
Middle fatal dose of flasking dose of substance that causes the death of 50% of animals in one-time introduction to the stomach.
Middle deadly dose when applied to the skin LD! -0 EDOCK substance that causes the death of 50% of animals when applied to the skin.
Threshold of chronic action 1LT (T- Minimum (threshold) concentration of harmful substance that causes harmful effects in a chronic experiment for 4 hours 5 times a week per month for at least 4 months.
The threshold of acute action 1ATAS - minimum (threshold) concentration of harmful substance, causing changes in biological indicators at the level of a holistic organism overlooking the limits of adaptive physiological reactions.
Zone of acute action 2As - the ratio of the average mortal concentration of the LC50 to the threshold of acute action Estab:
This ratio shows the range of concentrations that have an effect on the body in one-time arrival, from the initial to extreme, affecting the most unfavorable.
Zone of chronic zcr - the ratio of the threshold of the acute action of Limm. to the threshold of chronic Action Limr /;
This ratio shows how large the gap between the concentrations causing the initial phenomena of intoxication during one-time and long-term admission to the body. The smaller the zone of acute action, the more dangerous substance, since even a small excess of the threshold concentration can cause a deadly outcome. The wider the zone of chronic action, the more dangerous substance, since the concentrations that have chronic action, significantly less concentrations that cause acute poisoning.
The coefficient of possible inhalation poisoning (CVIO) - the ratio of the maximum achieved concentration of harmful substance in air at 20 ° C to the average mortal concentration of the substance for mice.
Maximum permissible concentration of harmful substance in the air of the working area PDKR; (- such a concentration of harmful substance in the air of the working area, which, with daily (except days) work for 8 hours or other duration, but not more than 40 hours per week, during the whole working experience cannot cause diseases or deviations in Health status detected by modern methods of research, in the process of OL's work in the long-term deadlines of the present and subsequent generations.
Fig. 3.1.
D (k) - dose (concentration)
The value of the PDKR is set at a level of two or three times lower than the threshold of chronic action. Such a decrease is called the reserve coefficient (K.J.
The dependence of the biological effect of chemicals from toxicological indicators is presented in Fig. 3.1.
In tab. 3.4 shows the classification of harmful substances by danger classes.
Table 3.4.
In real conditions, there are several chemicals in the air, which can have a combined effect on the human body. There are three possible effects (Fig. 3.2) of the combined effect of chemicals on the human body:
1 - the amount (additivity) is a phenomenon of summation of effects induced by a combined effect;
Fig. 3.2.
- 2 - potentiation (synergism) - enhancing effect effect (effect exceeding the amount);
- 3 - antagonism - the effect of combined impact is less than expected under the sum.
Rationing of a combined action
the case of additivity is responsible.
When potentiation use the formula
where x, - - amendment that takes into account the effect of effect; FROM, - actual concentrations of chemicals in the air of the working area; MPC - their extremely permissible concentrations.
Rationing of water quality rivers, lakes and reservoirs are carried out in accordance with the sanitary rules and norms of protection of surface water from pollution No. 4630-MR of the USSR in two categories of water bodies: I - drinking and cultural and domestic resources; II - fisheries.
The rules set the normalized values \u200b\u200bfor the following water parameters of water bodies: the content of floating impurities and suspended substances, the smell, taste, painting and water temperature, the pH value, composition and concentration of mineral impurities and dissolved in water oxygen, the biological need of water in oxygen, composition and MPC, Poisonous and harmful substances and pathogens bacteria.
The limiting index of harm (HD) for water bodies of drinking and cultural and domestic purposes is used by three species: sanitary-toxicological, commonitarian and organoleptic; For fisheries water reservoirs, along with the specified two more types of HPF - toxicological and fishery.
In tab. 3.5 Presents PDKV of some substances for water bodies.
The sanitary condition of the reservoir meets the requirements of the norms when performing the following relationship:
where St - concentration of substance / thug in the estimated reservoir; MPC is the maximum permissible concentration of the 1st substance.
For the water bodies of drinking and cultural and domestic purposes, the execution of three is checked, and five inequality for water bodies. In this case, each substance can be taken into account only in one inequality.
Table 3.5.
Hygienic I. technical requirements GOST 2761-84 is regulated to the sources of water supply and the rules for their choice in the interests of the health of the population. Hygienic requirements for the quality of drinking water of centralized drinking water supply systems are indicated in sanitary rules and Sanpine standards 2.1.4.559-96 and SanPine 2.1.4.544-96, as well as a GN 2.1.5.689-98.
Rationing chemical soil pollution it is carried out at maximum permissible concentrations (PDKP). This is the concentration of the chemical in arable layer of soil, mg / kg, which should not have a direct or indirect negative) influence on the matting environment and human health, as well as on the self-cleaning ability of the soil. By its magnitude, the PDCP is significantly different from the adopted permissible concentrations for water and air. This difference is due to the fact that the receipt of harmful substances into the body directly from the soil occurs in exceptional cases in minor quantities, mainly through the air, water, plants).
Pollution regulation is carried out in accordance with regulatory documents. There are four varieties of MPC "(Table 3.6) depending on the path of migration of chemicals in adjacent media: TV - a translocation indicator that characterizes the transition of a chemical substance from the soil through the root system in the green mass and fruits of plants; Ma is a migration air indicator, characterizing the transition Chemical substance from the soil into the atmosphere; MV is a migration aqueous indicator that characterizes the transition of a chemical substance from the soil into underground soil water and water sources; OS - an unitable indicator that characterizes the influence of a chemical on the self-cleaning ability of the soil and microbiocenosis. Hygienic assessment of the quality of soil inhabited areas is carried out According to Methodical instructions MU 2.1.7.730-99.
Table 3.6.
To estimate the content of harmful substances in the soil, samples are sampled on a section of 25 m2 in 3-5 points diagonally from a depth of 0.25 m, and when the effect of contamination on groundwater is clarified - from a depth of 0.75-2 m in an amount of 0.2 -1 kg. In the case of applying new chemical compounds for which there is no PDKP, the temporary allowable concentrations are calculated:
where PDKMR is an extremely permissible concentration for food (vegetable and fruit crops), mg / kg.
The professional diseases caused by the impact of harmful substances include acute and chronic intoxications that occur with an isolated or combined lesion of organs and systems: toxic damage to the respiratory organs (rinofaringolangitis, erosion, perforation of the nasal partition, tracheitis, bronchitis, pneumosclerosis, etc.); toxic anemia, toxic hepatitis, toxic nephropathy; toxic damage to the nervous system (polyneuropathy, neurosis-like states, encephalopathy); toxic eye damage (cataract, conjunctivitis, keratoconjunctivitis); Toxic bone damage (osteoporosis, osteosclerosis). The same group includes skin diseases: metal, fluoroplastic (teflon) fever, allergic diseases, neoplasms.
It should be borne in mind the possibility of the development of professional tumor diseases, especially respiratory organs, liver, stomach and bladder, leukemia with long-term contacts with distillation products of stone coal, oil, shale, with nickel compounds, chromium, arsenic, vinyl chloride, radioactive substances and etc., as well as professional diseases caused by the impact of industrial aerosols: pneumocoyeiosis (silicosis, silicatosis, metal coniosis, carboconiosis, pneumoconiosis from mixed dust, pneumoconiosis from plastics dust), bissing, chronic bronchitis.
In the habitat, there is a constant increase in the frequency of occupational diseases of allergic nature: conjunctivitis and rhinitis, bronchial asthma and asthmatic bronchitis, toxicodermia and eczema, toxico allergic hepatitis when exposed to chemicals - allergens. Among them, drugs are essential, such as vitamins and sulfonamides, substances of biological nature (hormonal and enzyme preparations, etc.).
The habitat factors common in the conditions of settlements can lead to an increase in common diseases, the development and flow of which is provoked by the unfavorable environmental influence. These include respiratory and allergic diseases of the respiratory organs, diseases of the cardiovascular system, liver, nights, spleen, violation of the female childbearing function, an increase in the number of children born with vices, a decrease in the sexual function of men, the growth of oncological diseases.
As a result of industrial activities in the air environment, various harmful substances in the form of vapors, gases, dust can be treated. The harmful substance is a substance that, when contacting a person's body, can cause production injuries, professional diseases or deviations in a state of health, both in the course of work and in the subsequent terms of life of the present and future generations.
Couples, gases, liquids, aerosols, compounds, mixtures in contact with the human body can cause diseases or deviations in a state of health, detected by modern methods of research, both in the process of contact with it and in the long-term deadlines of the present and subsequent generations. The effects of harmful substances per person may be accompanied by poisoning and injuries.
Currently, about 7 million chemicals and compounds are known, of which 60 thousand are used in human activity in the form of food additives, drugs, household chemicals.
Chemicals are classified on:
Industrial poisons used in production: organic solvents (dichloroethane), fuel (propane, butane), dyes (aniline);
Yadochimikats used in agriculture: pesticides;
Drugs (aspirin);
Household chemicals used in the form of food additives (vinegar),
Sanitation, personal hygiene, cosmetics;
Biological vegetable and animals of the poisons that are contained in plants (aconite, cicut), in mushrooms (agar), in animals (snakes) and insects (bees);
Poisoning substances (OB) - Zarin, Iprit, phosgene.
In the body, harmful chemicals can penetrate through the respiratory organs, the gastrointestinal tract and intact skin. However, the main way is the lungs. In addition to sharp and chronic professional poisoning, industrial poisons may cause a decrease in the body's stability and an increased overall morbidity.
According to the nature of the impact on a person, all harmful substances are divided into toxic and non-toxic. The toxic effect of harmful substances is the result of the interaction of the body, harmful substance and the environment.
The substance toxicity indicator is determined by its danger. The danger of a substance is the ability of a substance to cause negative effects for health effects in the conditions of production, city or in everyday life. The dangers of substances can be judged by the criteria for toxicity: MPC is a better permissible concentration in the air of the working area, water, soil; Shoes - an indicative safe level of impact for the same media; Quio - the coefficient of possible inhalation poisoning; Average deadly doses and concentrations in the air, on the skin, in the stomach, the magnitude of the thresholds of the harmful effect (single, chronic), odor threshold, as well as thresholds of a specific action (allergenic, carcinogenic, etc.).
The effect of exposure to various substances depends on the amount of substance that has fallen into the body, its physicochemical properties, the duration of receipt, chemical reactions in the body, from gender, age, individual sensitivity, ways of receipt and removal, distribution in the body, as well as meteorological conditions and other concomitant Environmental factors.
According to the degree of impact on the human body, harmful substances in accordance with the classification of GOST 12.1.007-76 "PRT. Harmful substances. Classification I. general requirements Safety »are divided into 4 hazard class:
2-high hazardous substances, PDC \u003d 0.1 ... 1.0 mg / m 3, for example, manganese, chlorine, nitric acid;
3 -Merly dangerous, PDC \u003d 1.0 ... 10 mg / m 3, for example, nitrogen dioxide, methyl alcohol, sulfuric anhydride;
Poisoning the most unfavorable form of negative impact of toxic substances per person. They can leak in acute and chronic forms.
Acute poisoning are group and occur as a result of accidents, breakdowns of equipment or gross violations of safety requirements; They are characterized by a short-term effect of poisons, not more than one shift; By entering the body of a harmful substance in relatively large quantities - at high concentrations in the air, an erroneous intake inside, severe contamination of the skin.
Chronic poisoning gradually, with long-term admission of poison in the body in relatively small quantities. The poisoning develops due to the accumulation of the mass of harmful substances in the body (material cumulation) or violations caused by them in the body (funny cumulation).
When re-influenced by the same poison in an octotoxic dose, the nature of the flow of poisoning may change and except for the cumulation, sensitization is developing (addiction).
In production, during the entire working day, the concentration of harmful substances is not permanent. They either grow by the end of the shift, declining for the lunch break, or hesitate sharply, providing a non-permanent effect on a person, which in many cases is becoming more harmful, as it leads to a breakdown of adaptation formation. This adverse action is noted when inhaling carbon monoxide.
Substances in the nature of the impact are divided into general oxic, which causing poisoning of the entire organism or affecting the CNS, blood formation, causing liver diseases, kidneys (lead, mercury); annoying, which cause irritation of mucous membranes respiratory tract, eyes, lungs, skin (chlorine, nitrogen oxides); sensitizing, acting as allergens (formaldehyde, solvents, varnishes); mutagenic, leading to a violation of the genetic code, change in hereditary information (lead, manganese, radioactive isotopes); Carcinogenic, causing malignant tumors (chromium, nickel, asbestos); Substances affecting reproductive (core) function (mercury, styrene, radioactive isotopes).
This classification does not take into account the large group of aerosols (dust), which do not have pronounced toxicity. They are characterized by fibrogenic effects on the body, which leads to the development of connective tissue in the air exchange zone and scarring (fibrosis) of the lungs.
Professional diseases associated with the effects of aerosols, pneumoconiosis (silicosis - develops under the action of free silicon dioxide, silicate - when ingestion of silicic acid salts, asbestosis is one of the aggressive forms of silicatosis), pneumosclerosis, chronic dust bronchitis occupy second place among all Professional diseases in Russia.
The presence of a fibrogenic effect does not exclude the general oxygen effects of aerosols.
Man in conditions modern production often subjected to a combined effect of harmful substances, as well as the effects of negative factors of other nature (physical - noise, vibration, electromagnetic and ionizing radiation). At the same time, the effect of combined (with the simultaneous action of negative factors of various nature) or a combined (with a simultaneous action of several chemicals) of the chemicals is the effect.
Combined action is a simultaneous or consistent effect on the body of several substances at the same way of their admission to the body. Depending on the effect of toxicity, several types of combined action are distinguished.
Many pollutants contained in emissions industrial enterprises and other sources of pollution, possess a similar toxic effect on living organisms. In addition, a number of substances can enhance their toxicity in the presence of others. This phenomenon is called the effect of the amount of harmful substance.
The amount (additive action) is the total effect of the mixture is equal to the sum of the effects of components included in the mixture. The amount is characteristic of substances of the appropriate action, when substances have the same effect on the same organism systems (for example, hydrocarbon mixtures);
For the hygienic assessment of the air environment with a joint presence of several substances in the air with the sum of action, the sum of their concentrations should not exceed the unit, i.e.
C 1 / PDC 1 + C 2 / PDC 2 + ... + with N / MPC N ≤ 1 (1)
where C 1, C 2, with n is the concentration of each substance in the air, which have the effect of the amount, mg / m 3
MPC 1 ... MPC n - the corresponding maximum permissible concentrations of these substances, mg / m 3
Potentiation (synergistic action) - substances act so that one substance enhances the effect of another. The effect of synergies is more additive. For example, alcohol significantly increases the risk of aniline poisoning.
Antagonism- One substance weakens the action of another. The effect is less additive. For example, Ezerin significantly reduces the action of anthropine, being its antidote.
Independence - The effect does not differ from the isolated action of each of the substances. Independence is characteristic of substances of multidirectional action, when substances have different effects on the body and affect different organs. For example, benzene and irritant gases.
Along with the combined effects of substances, an integrated effect is allocated. With a complex action, harmful substances enter the body at the same time, but different ways. For example, through respiratory and skin, respiratory organs and gastrointestinal tract)
Pairs, gases, liquids, aerosols, chemical compoundsMixtures (further substances) when contacting the human body can cause changes in a state of health or illness.
The effects of harmful substances per person may be accompanied by poisoning and injuries.
Currently, more than 7 million chemicals and compounds are known, of which about 60 thousand are used in human activity.
Classification and types of harmful substances
By chemical structure Harmful substances can be divided into the following groups:
- organic compounds (aldehydes, alcohols, ketones);
- element and organic compounds (phosphorodorganic, chloroorganic);
- inorganic (lead, mercury).
By aggregative state Harmful substances are divided into gases, pairs, aerosols and mixtures thereof.
According to the human body Harmful substances are divided into the following groups:
1. Toxic - The interaction with the human body, causing various deviations in the health state of the working. Depending on the physiological impact on a person, toxic substances can be conditionally divided into four groups:
- annoying acting on the respiratory tract and mucous membrane of the eye: sulfur gas, chlorine, ammonia, fluoride and chloride hydrogen, formatdehyde, nitrogen oxides;
- suffocating - violating the process of absorption of oxygen with tissues: carbon oxide, chlorine, hydrogen sulfide, etc.;
- narcotic - nitrogen under pressure, trichloroethylene, benzyl, dichloetancitylene, acetone, phenol, carbon tetrachloride;
- somatic - Causeing violation of the activities of the body or its individual systems: lead, mercury, benzene, arsenic and its compounds, methyl alcohol;
2. Sensitizing - causing neuroendocrine disorders accompanied by nest baldness, skin depigmentation;
3. Carcinogenic - causing cancer cells;
4. Generative - gonadotropic (acting on the sexual sphere), Embryotropic (acting on embryos), Mutagenic(acting on heredity).
5. Allergens - Causeing various allergic reactions. By the degree of danger to the human body, all harmful substances are divided into 4 hazard classes (GOST 12.1.007-76): 1st class - extremely dangerous; 2nd class - highly hazardous; 3rd grade - moderately dangerous; The 4th grade is low hazard.
Chemical substances depending on their practical use Classified on:
- industrial poisons - organic solvents used in production (for example, dichloroethane), fuel (for example, propane, butane), dyes (for example, aniline), etc.;
- yadochimikats - used in the agriculture of pesticides and others;
- medicines;
- household chemicals are used in the form of food additives (for example, vinegar), sanitation, personal hygiene, cosmetics, etc.;
- biological vegetable and animals of the poisons, which are contained in plants, mushrooms, in animals and insects;
- poisoning substances (s) - Zarin, Hyprit, phosgene, etc.
Types of harmful substances by the nature of the impact on a person:
- generaloxic - Causes to poisoning the entire body or affecting individual systems: a central nervous system, hematopoietic organs, liver, kidneys (hydrocarbons, alcohols, aniline, hydrogen sulfide, blue acid and its salts, mercury salts, chlorinated hydrocarbons, carbon monoxide, etc.);
- annoying causing irritation of mucous membranes, respiratory tract, eyes, lungs, leather (organic nitrogenants, dimethylaminobenzene and other antibiotics, etc.);
- sensitizing - acting as allergens (formaldehyde, solvents, varnishes, etc.);
- mutagenic - leading to a violation of genetic code, change in hereditary information (lead, manganese, radioactive isotopes, etc.);
- carcinogenic - causing malignant tumors (chromium, nickel, asbestos, benz (a) IYEV, aromatic amines, etc.);
- affecting reproductive (core) function - Causeing congenital defects, deviations from the normal development of children affecting the normal development of the fetus (mercury, lead, styrene, radioactive isotopes, boric acid, etc.).
Hazard classes of harmful substances
In the human body, harmful chemicals can penetrate through the respiratory organs, the gastrointestinal tract, the skin. The main way of penetrating harmful substances into the body is respiratory organs.
The distribution of harmful substances in the body is subject to certain patterns. First, the distribution of the substance in the body is occurring, then the absorption capacity of the tissues begins to play the main role.
The harmful effect of chemicals on the human body is studied special science - toxicology.
Toxicology - This is a medical science that studies the properties of poisonous substances, the mechanism of their action on the living organism, the essence of the pathological process (poisoning) caused by them, methods of its treatment and warnings. The region of toxicology that studies the effect of chemicals per person in the conditions of production is called industrial toxicology.
Toxicity - This is the ability of substances to have a harmful effect on living organisms.
The main criterion (indicator) of the toxicity of the substance is the PDC (unit of measurement of the concentration is mg / m 3). The substance toxicity indicator determines its danger. By the degree of danger, harmful substances are divided into four classes (Table 1).
Table 1. Classes of danger of substances on the MPC in the air of the working area (according to GOST 12.1.007-76)
In addition to the indicator of the PDC, which defines the hazard class on the concentration of the substance in the air, other indicators are used.
Average deadly concentration in air LC 50 (mg / m 3) - the concentration of the substance that causes the death of 50% of animals with two or four-hour inhalation.
Average deadly dose when applied to leather LD 50 (mg / kg - milligram harmful to kg of animal mass) dose of a substance that causes the death of 50% of animals in one-time application to the skin.
Middle deadly dose for 50 (mg / kg) - dose of a substance that causes the death of 50% of animals in one-time introduction to the stomach.
In determining the specified average fatal concentrations and doses of testing, they are carried out on mice and rats.
At the specified indicators, the hazard class of the substance is determined by the following quantitative values \u200b\u200b(Table 2).
Harmful substance is a substance that in case of violation of safety requirements may cause production injuries, professional diseases, deviations in a state of health, detected both in the process and in the long-term deadlines for the life of these and subsequent generations.
Harmful substances that allocate in the air of the working area change its composition, as a result of which it may differ significantly from the composition of atmospheric air.
There are various classifications of harmful substances that are based on their effect on the human body. In this regard, harmful substances are divided into 6 groups:
· General oxic;
· Irritating;
· Sensitizing;
· Carcinogenic;
· Mutagen;
· Influencing the reproductive function of a person
Generaloxic Substances cause poisoning of the entire body. It is carbon oxide, lead, mercury, arsenic.
Annoying Substances cause irritation of the respiratory tract and mucous membranes of the human body. These include: chlorine, ammonia, acetone couple, ozone.
Sensitizing substances (Sensitization - an increase in the reactive sensitivity of cells and tissues of the human body) act as allergens. This property has formaldehyde, various nitro compounds.
Impact carcinogenic substances The human body leads to the emergence and development of malignant tumors. Carcinogenic are: chromium oxides, beryllium and its compounds, asbestos.
Mutagenic substances When exposed to the body cause changes in hereditary information. These are radioactive substances, manganese, lead.
Among substances affecting the reproductive function of the human bodyshould first be called mercury, lead, manganese, row radioactive substances and etc.
Currently, about 7 million chemicals and compounds are known, of which 60 thousand are used in human activity: 5500 - in the form of food additives, 4000 - drugs, 1500 - household chemicals.
All chemicals depending on their practical use are classified on:
· Industrial poisons used in production - organic solvents, fuel (uranium, butane), dyes (aniline);
· Yadhimikati used in C / X (pesticides);
· Medicines (aspirin);
· Household chemicals used in the form of food additives (vinegar), sanitation products, personal hygiene, cosmetics;
· Biological vegetable and animals of the poisons, which are contained in plants, in mushrooms, in animals and insects;
· Poisoning substances - Zarin, Iprit, phosgene.
In the body, industrial chemicals can penetrate through respiratory organs, gastrointestinal tract and intact skin. But the main way is the lungs.
Household poisonings most often occur when poison in the gastrointestinal tract.
The distribution of poisonous substances in the body is subject to certain patterns. First, the dynamic distribution of the substance determined by the intensity of blood circulation occurs. The main role is then played by the absorption capacity of tissues. For a number of metals (silver, manganese, chrome, vanadium, cadmium) is characteristic of the rapid removal of blood and accumulation in the liver and kidneys. Barium compounds, beryllium and lead form durable compounds with calcium and phosphorus and accumulate in bone tissue.
The toxic effect of harmful substances is the result of the interaction of the body, harmful substance and the OS.
It is customary to identify only those that their harmful effects exhibit under normal conditions and in relatively small quantities.
Industrial poisons include a large group of industrial substances and compounds, which in the form of raw materials, intermediate or finished products are found in production.
The total toxicological classification of poisons includes the following types of impact on living organisms:
· Neriva-paralytic (cramps, paralysis);
· Local inflammation in combination with general oxygen phenomena (acetic essence);
· General toxic (coma, brain swelling, cramps) for example, alcohol and surrogate, carbon monoxide;
· Tempery and irritant, for example, pairs of strong acids and alkalis;
· Psychotropic - drugs, Atropine.
Poons can have both selective toxicity, i.e. Can be dangerous for a specific system of organs or a specific organ.
They are divided into:
· Heart with predominant cardiotoxic effect (drugs, vegetable poisons, metals salts);
· Nervous, causing violation of mental activity (carbon monoxide, alcohol, drugs, hypnotics);
· Hepatic (hydrocarbons, poisonous mushrooms, phenols and aldehydes);
· Renal (heavy metals compounds, oxalic acid);
· Blood - Analin, nitrites, arsenic hydrogen;
· Little - nitrogen oxide, ozone.
In the body, industrial and chemicals can penetrate through the respiratory organs, the gastrointestinal tract and damaged skin.