Every day, people are exposed to thousands of different chemicals. Many are worried about their state of health and are trying to find the answer to the questions: which of them are dangerous, and can they cause cancer or other problems? But this problem should not be considered only in connection with the possible impact of harmful industries on the environment, since there are risks associated with improper nutrition, self-medication and other behavioral factors. For example, food salt (its NaCl formula) is used daily in food. But after all, in accordance with the current regulatory documents, it belongs to hazard class III. And ethylene (its chemical formula C2H4) is a less harmful substance, which is included in class IV hazard. So after all, what do such concepts as harmful substances and their classification include? What documents are they installed?
The answers to these questions are given by GOST 12.1.007-77 *. Harmful substances are chemical compounds that, due to violations of safety requirements, can cause (in contact with the human body) health problems, occupational diseases or work- related injuries. All these problems are usually found already in the process of their impact or in remote periods of life, and even in subsequent generations. Also, the standard establishes (depending on the degree of impact on the human body) for various chemicals contained in raw materials, intermediates, products and wastes, only four hazard classes. Thus, all harmful substances are usually classified as extremely hazardous (class I), highly hazardous (class II), moderately hazardous (class III) or low hazard (class IV).
Gradation is carried out in the process of comparing actual values with standard values for specific indicators. They include the maximum permissible (for the air of the working zone) concentration of harmful substances, the average lethal dose when they enter the stomach, the average lethal dose when exposed through the skin, the average lethal concentration for working air, and the coefficient of possible poisoning by acute and chronic zones actions. Thus, the hazard class of harmful substances, according to is a conditional value, which is intended for the classification of potentially dangerous chemical compounds.
Standards for MPC in the air of industrial premises and their hazard class are specified in Appendix No. 2 to GOST 12.1.005-88 for more than 1300 items. An even greater amount of similar information can be found in the hygienic standards GN 2.2.5.1313-03. It is useful to dwell on some substances, and also in this connection it is appropriate to recall the negative role of improper unbalanced nutrition and the dangers of smoking (both for active and passive smokers). Indeed, tobacco smoke contains such harmful substances as benzapyrene, carbon monoxide, nicotine, soot and others. For comparison, it is necessary to consider the MPC and hazard classes of certain chemical compounds that enter the human body when taking medicines, with food, or as a result of smoking:
- benzapyrene - 0.00015 mg / m3, class I;
- nicotinamide (vitamin PP) - 1 mg / m3, class II;
- soot - 20 mg / di3, class III;
- carbon monoxide (carbon monoxide) - 20 mg / di3, class III;
- sodium chloride (food salt) - 5 mg / m3, class III;
- oxalic (ethanedione) acid - 5 mg / m3, class III;
- ethylene - 100 mg / m3, class IV.
Obviously, vitamin PP, food salt and oxalic acid are more dangerous substances for humans than the chemical product ethylene, which is produced in large-scale industries and serves as raw material for the production of polyethylene (and from it they make film, containers and other useful products). Special attention should be paid to the dangers associated with:
- With the wrong diet. A good example is oxalic acid. MPC for water bodies is 0.5 mg / dm3. It is found in beets (0.61%), green onions (1.48%), parsley (1.70%), spinach (0.97%), rhubarb (0.75%). Thus, if half the beets are included in the diet (the weight of the root crop is 300 g), then about 1 g of oxalic acid will enter the human body. According to some sources, a lethal dose is considered to be 5 g when taken orally.
- With smoking. Every six seconds, one person dies in the world due to smoking-related diseases - this is WHO data. At the same time, there is an annual increase in mortality. It is expected that by 2020 a huge number will double and reach 10 million people a year.
It is obvious that harmful substances enter the body not only due to adverse environmental conditions, as emphasized in many media, but also due to unreasonable human behavior. Despite the wide opportunities for obtaining useful information, people continue to eat, smoke, drink alcohol or drugs improperly. Only by realizing all the risks, establishing a balanced diet and giving up bad habits, you can significantly reduce the effect of harmful substances on the body.