Objective:

1. Acquainted with general principles classification of working conditions according to the degree of harmfulness and danger.

   To study the features of the thermal interaction of a person with the surrounding air (microclimate).

   Learn rationing microclimate indicators.

   To study ways to measure microclimate indicators, measure them and compare them with standards.

   To study ways to protect against the adverse effects of the microclimate

1. Regulations

1. Sanitary rules and norms SanPiN 2.2.4.548-96. Hygienic requirements for the microclimate of industrial premises.

2. Guide R. 2.2.755-99. Hygienic criteria for assessing and classifying working conditions in terms of hazard and hazard factors production environment. severity and intensity of the labor process.

3. GOST 12.1.005-88.SSBT. General sanitary and hygienic requirements for the air of the working area

In addition to those listed, there are some other industry documents.

3. Explanation of terms used in the work

Microclimate. The concept of microclimate is given in section 6.

Working conditions- a set of factors of the working environment and the labor process that affect the health and performance of a person in the labor process.

Hazardous production factor- a production factor, the impact of which on a worker under certain conditions leads to injury, acute poisoning or other sudden sharp deterioration in health or death.

Harmful production factor- a production factor, the impact of which on a worker under certain conditions can lead to illness, a decrease in working capacity and (or) negative influence on the health of the offspring.

In accordance with GOST 12.0.003, all hazardous and harmful production factors (OHPF) are divided into four groups:

physical group factors,

chemical group factors,

biological factors,

psychophysiological group factors

Microclimate parameters that do not meet the requirements of regulatory documents belong to the group of physical OVPF

Safe working conditions- the state of working conditions under which the impact on workers of hazardous or harmful production factors is excluded, or the impact of harmful production factors does not exceed the maximum permissible values.

Occupational diseases- a chronic or acute illness of a worker, which is the result of exposure to a harmful production factor.

The severity of labor- a characteristic of the labor process, reflecting the predominant load on musculoskeletal system and functional systems of the body (cardiovascular, respiratory, etc.) that ensure its activity. It is characterized by physical dynamic load, the mass of the load being lifted and moved, total number stereotyped working movements, the magnitude of the static load, the form of the working posture, the degree of inclination of the body, movements in space.

Labor intensity- a characteristic of the labor process, reflecting the load mainly on the central nervous system, sensory organs, and the emotional sphere of the worker. These include intellectual, sensory, emotional loads, the degree of monotony of loads, the mode of operation.

Production room- a closed space in specially designed buildings and structures in which people constantly (in shifts) or periodically (during the working day) carry out activities.

Workplace- all places where the worker has to be or where he has to go in connection with his work and which are directly or indirectly under the control of the employer.

permanent workplace - the place where the employee is most of his working time (more than 50% or more than 2 hours continuously)

- Warm period of the year- a period of the year characterized by an average daily outdoor temperature above 10 0 С.

- Cold period of the year- a period of the year characterized by an average daily outdoor temperature of less than 10 0 С.

Certification of workplaces according to working conditions- a system for analyzing and evaluating workplaces for conducting recreational activities, familiarizing employees with working conditions.

General principles for the classification of working conditions according to the degree of harmfulness and danger

Working conditions, based on hygienic criteria (R.2.2.755-99), are divided into 4 classes:

1st class - optimal; 2nd class - acceptable;

3rd class - harmful; 4th class - dangerous;

Separately classified working conditions for injury safety.

1st class - optimal working conditions (definition optimal conditions labor is given in section 8).

MICROCLIMATE OF INDUSTRIAL PREMISES — weather conditions the internal environment of the premises, which are determined by the combinations of temperature, humidity, air velocity and thermal radiation acting on the human body; a complex of physical factors that affect the heat exchange of a person with the environment, the thermal state of a person and determine well-being, performance, health and performance labor. Microclimate indicators: air temperature and its relative humidity, its speed, power thermal radiation.

Human life can proceed normally only if the temperature homeostasis of the body is maintained, which is achieved through the thermoregulation system and the activity of other functional systems: cardiovascular, excretory, endocrine, and systems that provide energy, water-salt and protein metabolism. To maintain a constant body temperature, the body must be in a thermostable state, which is assessed by heat balance. Thermal balance is achieved by coordinating the processes of heat production and heat transfer. The microclimate (hereinafter - M.), according to the degree of influence on the heat balance of a person, is divided into neutral, heating, cooling.

Neutral microclimate when exposed to a person for work shift ensures the thermal balance of the body. The difference between the value of heat production Q m and total heat transfer Q soum is within 2 W, the share of heat transfer by evaporation of moisture does not exceed 30%.

Cooling microclimate- a combination of parameters at which the total heat transfer to the environment Q soum exceeds the amount of heat production of the body. This leads to the formation of a general and (or) local heat deficit in the human body (> 2 W). Cooling M. leads to an exacerbation of peptic ulcer disease, sciatica, causes the occurrence of diseases of the respiratory system, cardiovascular system.

With pronounced cooling, the number of platelets and erythrocytes in the blood increases, the cholesterol content and blood viscosity increase, which increases the possibility of thrombosis. Cooling of a person (both general and local) leads to a change in his motor response, disrupts coordination and the ability to perform precise operations, causes inhibitory processes in the cerebral cortex, which can cause various forms of injury. With local cooling of the brushes, the accuracy of performing work operations is reduced. The performance decreases by 1.5% with each degree decrease in finger temperature.

Chronic cooling (including local) in progress labor activity causes primarily "cold" neurovasculitis, Raynaud's syndrome, angiotrophoneurosis. Symptoms of chronic cold damage to the feet and hands are a decrease in skin temperature, a violation of tactile sensitivity, an increase in humidity, and trophic disorders. The effect of chronic cooling is exacerbated by the effect of local vibration. At the same time, the development of vibration damage is reduced.

Heating microclimate- a combination of parameters in which there is a change in heat exchange between a person and the environment, manifested in the accumulation of heat in the body (> 2 W) and (or) in an increase in the proportion of heat loss by evaporation of moisture (> 30%). The impact of heating M. also causes a violation of the state of health, a decrease in working capacity and labor productivity. Heating M. can lead to a disease of a general nature, which manifests itself most often in the form of a thermal collapse. It occurs due to the expansion of blood vessels and a decrease in blood pressure in them. At the same time, the body temperature is not too high. Fainting is preceded by headache feeling of weakness, dizziness, nausea. The skin first turns red, then turns pale and covered with a cold sweat. The heart rate increases. This condition quickly passes when resting in a cool place.

Heating M. is the cause of diseases of non-infectious origin. The intense sweating that occurs under these conditions is accompanied by the loss of salts and water in the body. The number of platelets in the blood and its viscosity increase, the level of cholesterol in the blood plasma, which increases the likelihood of thrombosis (in particular, cerebral arteries). The incidence among workers in hot shops is 1.2-2.1 times higher than among workers who are not constantly exposed to heating M.

Thermal load in the main shops of metallurgical production causes 37% of all diseases of the respiratory system and 39% of diseases of the digestive system. Diseases arise of cardio-vascular system associated with a significant hemodynamic stress, manifested in the form of persistent myocardiopathy, neurocirculatory dystonia of the hypertensive type. There is an intensive biological aging of workers whose work is associated with significant thermal and physical stress, especially in the age group of 50 years. Headaches, excessive sweating and fatigue are observed. A significant increase in standardized mortality rates from diseases of the cardiovascular system was revealed.

Heatstroke very dangerous. Even with early detection, one in five cases is fatal. With general thermal stagnation, body temperature rises significantly, leading to direct tissue damage, especially in the CNS. Nausea and vomiting precede the shock stage with a deep loss of consciousness, sometimes accompanied by convulsions. Due to the disorder of the thermoregulation center, sweating is reduced. The skin is hot, dry, at first red, and then becomes gray. Mortality is higher the higher the body temperature.

Persons who are overweight are especially susceptible to heat stroke. There is a linear relationship between its excess and the relative probability of death from heat stroke. The highest frequency of heat stroke occurs in people aged 46 years and older. Relatively often, heat strokes happen to people of younger age (18-20 years). In the first weeks of operation in a heating environment, thermal shocks are more common than in subsequent weeks.

As a result sunstroke first of all, brain functions are disturbed due to local overheating of the head unprotected from the sun. To heat exhaustion can lead to a decrease in moisture in the body. Reducing the moisture content in the human body by 1-2% of the total mass does not lead to any significant changes in the body (except for the feeling of thirst). with reinforcement dehydration phenomena such as drowsiness, uncoordinated movements and a significant decrease in performance occur. With a moisture deficit of more than 10% of body weight, loss of consciousness occurs, sometimes a state of strong arousal and death.

Defined as thermal state(TS) the functional state of a person, due to his heat exchange with the environment, characterized by the content and distribution of heat in the deep ("core") and surface ("shell") tissues of the body, as well as the degree of tension of thermoregulation mechanisms.

Indicators TC:

Skin temperature (weighted average and local);

The temperature of the "core" of the body;

Average body temperature;

Change in heat content in the body;

The amount of moisture loss;

Change in heart rate;

Heat sensation.

The classification of the TS (optimal, permissible, maximum permissible, unacceptable) and method its assessment in order to substantiate the hygienic requirements for M. work places, as well as measures to prevent cooling and overheating workers. According to the degree of influence on the well-being of a person, his performance microclimatic conditions subdivided into optimal, permissible, harmful and dangerous.

Optimal microclimatic conditions are characterized by such parameters of indicators of M., which, with their combined effect on a person during a work shift, provide optimal TC of the body. Under these conditions, the thermoregulation stress is minimal, general and (or) local uncomfortable heat sensations are absent, which allows maintaining high performance.

Permissible microclimatic conditions are characterized by such parameters of indicators of M., which, with their combined effect on a person during a work shift, can cause a change in TS. This leads to a moderate tension of thermoregulation mechanisms, slight uncomfortable general and (or) local heat sensations. At the same time, relative thermal stability is preserved, there may be a temporary (during the work shift) decrease in working capacity, but health is not disturbed (during the entire period of labor activity). Such parameters of M. are admissible which at their joint action on the person provide admissible TS of an organism.

Harmful microclimatic conditions M. parameters, which, when combined with a person during a work shift, cause changes in the body's TS: pronounced general and (or) local uncomfortable heat sensations, significant stress on the mechanisms of thermoregulation, and a decrease in working capacity. At the same time, the thermal stability of the human body and the preservation of its health during the period of labor activity and after its completion are not guaranteed. The degree of harmfulness of M. is determined both by the magnitude of its components and the duration of their impact on workers (continuously and in total for a work shift, for a period of labor activity).

Dangerous(extreme) microclimatic conditions- M. parameters, which, with their combined effect on a person, even for a short time (less than 1 hour) cause a change in the TS, characterized by excessive stress on the mechanisms of thermoregulation, which can lead to a violation of the state of health and the occurrence risk of death.

Regulatory requirements for individual indicators of M., their combinations, developed on the basis of a study of heat transfer and human TS in microclimatic chambers and in production conditions, as well as on the basis of clinical and epidemiological studies, are set out in SanPiN 2.2.4.548-96.

AT industrial premises where it is not possible to maintain the permissible standard values ​​of M., it is necessary to take measures to protect workers from possible overheating and cooling.

This is achieved by various means:

The use of local air conditioning systems;

Using personal protective equipment from high or low temperature;

Regulation of periods of work in unfavorable M. and rest in indoors with M., normalizing the HARDWARE;

Reducing work shifts, etc.

Prevention of overheating workers in heating M. includes the following activities:

Rationing of the upper limit of the external thermal load at an acceptable level in relation to an 8-hour work shift;

Regulation of the duration of exposure to the heating medium (continuously and per shift) to maintain the average shift vehicle at an optimal or acceptable level;

The use of special SKZ and PPE, which reduce the flow of heat from the outside to the surface of the human body and provide acceptable TC for workers.

Cooling protection carried out by means of clothing made in accordance with the requirements of GOST 29335-92 and 29338-92 "Costumes for men and women for protection against low temperatures. Specifications". To reduce heat loss, local heat sources can also be used to ensure the preservation of the proper level of general and local heat transfer of the body. The use of clothing does not preclude compliance with the proper regulation of the time of work in an unfavorable environment, as well as the general work regime approved by the relevant enterprise and agreed with the SSES bodies. To normalize the body's TS, the duration of continuous exposure to the cold and the duration of stay in a room with comfortable conditions are regulated.

Microclimate

Microclimate industrial premises- this is the climate of the internal environment of these premises, which is determined by the combinations of temperature, humidity and air velocity acting on the human body, as well as the temperature of the surrounding surfaces. The meteorological conditions of the working environment (microclimate) affect the process of heat transfer and the nature of the work. The microclimate is characterized by air temperature, its humidity and speed of movement, as well as the intensity of thermal radiation. Prolonged exposure of a person to unfavorable meteorological conditions sharply worsens his state of health, reduces labor productivity and leads to diseases.

High air temperature contributes to rapid fatigue of the worker, can lead to overheating of the body, heat stroke. Low air temperature can cause local or general cooling of the body, cause colds or frostbite. Air humidity has a significant impact on the thermoregulation of the human body. High relative humidity (the ratio of water vapor content in 1 m 3 of air to their maximum possible content in the same volume) at high air temperature contributes to overheating of the body, while at low temperature it enhances heat transfer from the skin surface, which leads to hypothermia of the body.

Low humidity causes the mucous membranes to dry out. Air mobility effectively contributes to the heat transfer of the human body and is positively manifested when high temperatures ah, but negatively low. To create normal working conditions in industrial premises, standard values ​​of microclimate parameters are provided: air temperature, its relative humidity and speed of movement, as well as the intensity of thermal radiation.

In the process of labor in a production facility, a person is under the influence of certain conditions, or microclimate - the climate of the internal environment of these premises. The main normalized indicators of the air microclimate of the working area include temperature, relative humidity, air velocity. The intensity of thermal radiation of various heated surfaces, the temperature of which exceeds the temperature in the production room, also has a significant impact on the parameters of the microclimate and the state of the human body.

Relative humidity is the ratio of the actual amount of water vapor in the air at a given temperature to the amount of water vapor that saturates the air at that temperature.

If there are various heat sources in the production room, the temperature of which exceeds the temperature human body, then the heat from them spontaneously passes to a less heated body, i.e. to a person. There are three ways of heat propagation: conduction, convection and thermal radiation.

A person in the process of labor is constantly in a state of thermal interaction with the environment. For the normal course of physiological processes in the human body, it is necessary to maintain an almost constant temperature (36.6 ºС). The ability of the human body to maintain a constant temperature is called thermoregulation. Thermoregulation is achieved by the removal of heat released by the body in the process of life into the surrounding space. Heat transfer from the body to the environment occurs as a result of: heat conduction through clothing; body convection; radiation to surrounding surfaces, evaporation of moisture from the surface of the skin; heating of exhaled air. The normal thermal well-being of a person when performing work of any category of severity is achieved subject to the thermal balance. Let us consider how the main parameters of the microclimate affect the heat transfer from the human body to the environment.

Effect of ambient temperature on human body associated primarily with the narrowing or expansion of blood vessels in the skin. Under the influence of low air temperatures, the blood vessels of the skin narrow, as a result of which the flow of blood to the surface of the body slows down and heat transfer from the surface of the body decreases due to convection and radiation. At high ambient temperatures, the reverse picture is observed: due to the expansion of the blood vessels of the skin and an increase in blood flow, heat transfer increases significantly. The normative documents introduce the concepts of optimal and permissible microclimate parameters.

Optimal microclimatic conditions are such combinations of quantitative parameters of the microclimate that, with prolonged and systematic exposure to a person, ensure the preservation of normal functional and thermal state body without straining the mechanisms of thermoregulation.

Permissible conditions are provided by such a combination of quantitative parameters of the microclimate, which, with prolonged and systematic exposure to a person, can cause transient and rapidly normalizing changes in the functional and thermal state of the body, accompanied by a tension in the mechanisms of thermoregulation that does not go beyond the limits of physiologically adapted capabilities.

To maintain normal microclimate parameters in working area apply: mechanization and automation of technological processes, protection from sources of thermal radiation, installation of ventilation, air conditioning and heating systems. An important place is also given to the proper organization of work and rest for workers performing labor-intensive work in hot shops.

The mechanization and automation of the production process makes it possible to drastically reduce the labor load on a person (the mass of the load lifted and moved manually, the distance of movement of the load, to reduce the transitions due to the technological process), to completely remove a person from the production environment, shifting his labor functions to automated machines and equipment. To protect against thermal radiation, various heat-insulating materials are used, heat shields and special ventilation systems (air showering) are arranged. Thermal protective equipment should provide thermal exposure at workplaces of not more than 350 W / m2 and equipment surface temperature not higher than

35ºС at a temperature inside the heat source up to 100 ºС and not higher than 45 ºС - at a temperature inside the heat source above 100 ºС.

There are heat-reflecting, heat-absorbing and heat-removing screens. Heat-reflecting screens are made of aluminum or steel, as well as foil or mesh based on them. Heat-absorbing screens are structures made of refractory bricks, asbestos cardboard or glass. Heat shields are hollow structures cooled from the inside with water.

A kind of heat-removing transparent screen is the so-called water curtain, which is arranged at the technological openings of industrial furnaces and through which tools, processed materials, workpieces, etc. are introduced into the furnaces.

Severity

The level of human energy consumption in various forms of activity serves as a criterion for the severity and intensity of the work performed, is of great importance for optimizing working conditions and its rational organization.

BX- this is the minimum energy exchange necessary to maintain the life of the body in a state of complete rest, with the exclusion of all internal and external influences that can increase the level of metabolic processes. The body's need for energy is mainly determined by the level of metabolic processes aimed at maintaining the constancy of the internal environment of the body and self-renewal of its morphological structures, energy consumption for labor activity, adaptation (adaptation) of the body to changing conditions environment, leisure. An objective indicator of energy consumption for a certain period of time is the value of the total energy consumption of the body for the same period. Total energy expenditure is the sum of energy expenditure for basal metabolism, muscle activity and the specific dynamic effect of food.

The basal metabolic rate depends mainly on age, height, body weight and gender. As an integral indicator of the intensity of redox processes in tissues at rest, the basic metabolism to a certain extent depends on the state internal organs and external influences on the body. It can change with insufficient or excessive nutrition, exposure to climatic factors, hypoxia, dysfunction of the endocrine glands and diseases, if they are accompanied by a feverish state.

Muscular activity has the strongest influence on energy metabolism. Even during wakefulness, the energy exchange always exceeds the basal metabolism, and the degree of increase in energy consumption depends, first of all, on the nature of the work performed and the level of physical activity, which are associated with muscle activity and determine the intensity of the body's functioning. The severity and intensity of labor activity, the environmental conditions (temperature, humidity, air movement, etc.) in which it is performed, and the fitness of the individual matter.

Energy costs vary depending on the working posture. So, in a working posture sitting, energy costs exceed the level of basal metabolism by 5-10%; standing - by 10-25%; with a forced uncomfortable position - by 40-50%. With intensive intellectual work, the brain's need for energy is 15-20% of the total metabolism in the body. The increase in total energy costs during mental work is determined by the degree of neuro-emotional tension. Daily energy consumption during mental work increases by 48% when reading aloud while sitting, by 90% - when reading a lecture, by 90-100% for computer operators. In addition, the brain is prone to inertia, because after the cessation of work, the thought process continues, which leads to greater fatigue and exhaustion of the central nervous system than during physical labor.

The duration and intensity of the increase in energy metabolism can vary significantly depending on the individual characteristics of the body, as well as the quantity and quality of food taken. Increased energy metabolism when taking various nutrients called specific dynamic action (SDA) food. SDD is a complex reflex process in which food breakdown products have a direct effect on cellular metabolism and (or) are accompanied by a change in the functional activity of the gastrointestinal tract.

Table No. 49. Severity work based on the total energy costs of the body. Categorization of working groups of the population by energy costs for light physical work, moderate physical work and heavy physical work is carried out in accordance with SanPiN " Hygiene requirements to the microclimate of industrial premises”, approved by the Ministry of Health of the Republic of Kazakhstan on July 14, 2005, No. 355 (Table No. 49).

Category	Working conditions
I	light physical work
I a	Activities that include work performed while sitting and not requiring physical exertion and in which energy consumption is up to 120 kcal / h
I b	Activities that include work performed while sitting, standing or walking and accompanied by some physical stress, energy consumption is from 120 to 150 kcal / h
II	Physical work of moderate severity
II a	Activities that include work related to walking, moving small (up to 1 kg) products and objects in a standing or sitting position and requiring a certain physical exertion. Energy consumption is 150 to 200 kcal/h
II b	Activities that include work performed while standing, associated with walking, carrying small (up to 10 kg) weights and accompanied by moderate physical exertion. Energy consumption is between 200 and 250 kcal/h
III	Heavy physical work
Activities that include work associated with constant movement, moving and carrying significant (more than 10 kg) weights and requiring great physical effort. Energy consumption exceeds 250 kcal/h

Knowledge of energy consumption is necessary not only to identify groups of labor intensity, but also to determine the energy needs of people different ages and professions in the specific conditions of their life and work. Daily energy expenditure, and hence energy demand, can be viewed as consisting of energy expenditure for productive activities, off-duty work, and sleep. Data on the energy needs of a "standard" man and a "standard" woman can be used as a starting point for calculating the energy needs of men and women of various professional and age groups of the population. In such calculations, corrections are also used that take into account the influence on the need for energy of factors such as body weight, age, gender, the influence of working conditions and environmental factors.

Microclimate

Hygienic standardization of parameters industrial microclimate established by the norm of labor safety standards, as well as SNiP 2.584-96. Normalized minimum and valid parameters microclimate - temperature, relative humidity and air velocity. The values ​​of the microclimate parameters are set depending on the person's ability to acclimatize at different times of the year and the category of work in terms of energy consumption. The period of the year determines the body's ability to acclimatize, and hence the value of the optimal and acceptable parameters.

When normalizing, a warm and cold period of the year is distinguished. The warm period of the year is characterized by an average daily outdoor temperature above +10°, and the cold period of the year is +10° and below.

When normalizing microclimate parameters, categories of work are taken into account according to the severity of performance based on the total energy costs of the body per unit of time.

There are the following categories of work:

1) Light physical work - all activities that are performed while sitting, standing or walking and accompanied by some physical stress (seamstresses, controllers);

2) Physical work of moderate severity - work associated with constant walking and moving small ones up to 1 kg. products, work related to walking and moving weights up to 10 kg. (professions in foundries, forgings, welding shops);

3) Heavy physical work - work associated with systematic physical stress and carrying significant weights over 10 kg.

Psychophysical and economic bases of labor safety.

Mental processes, properties and conditions affecting labor safety.

Human mental activity includes:

mental processes;

Mental properties;

mental states.

Mental processes form the basis mental activity. There are cognitive, emotional and volitional mental processes.

When establishing hygienic standards for the microclimate of premises, they proceed from the fact that they must provide thermal comfort for a person. In the case of normal microclimatic conditions, about 10% of people (on average) still feel thermal discomfort. This is due to individual differences in the intensity of metabolic processes, the thickness of the subcutaneous fat layer, national and social characteristics, etc. The microclimate is considered favorable if the number of subjective ratings "comfort" or "normal" is more than 75%, and uncomfortable - less than 25%.

For hygienic regulation the microclimate of the premises, the following should be taken into account:

Conditions of people's activity (appointment of premises);

Seasonal difference in microclimate parameters (separate for warm and cold periods of the year);

The need to create a narrow range of normalized microclimate parameters.

In addition, it is necessary to substantiate the individual components of the microclimate, which together create a feeling of thermal comfort in a person. Thermal comfort is understood as meteorological environmental conditions that contribute to the optimal level of physiological functions, including thermoregulatory ones, with a subjective feeling of comfort. As can be seen, the subjective factor plays the main role in this.

It is impossible to establish uniform hygienic standards for microclimate indicators various premises, since it is impossible to impose the same hygienic requirements, for example, on the microclimate of residential premises.

Most researchers believe that the boundary of the deterioration of mental performance is the temperature in the premises of 28-30 ° C, above which the number of erroneous reactions from operators increases. So at an air temperature of 27-31C - °, the number of errors when working with Morse code increases by 50%, at 36-50 °C they increase six times.

At a temperature of 40-50 ° C and a relative humidity of 70-80%, the pace of mental work is halved, concentration of attention drops sharply with an increase in the number of errors by 5-6 times, with a further increase in air temperature, coordination of movements is disturbed. Physical performance in conditions of high air temperatures decreases later.

Regardless of the state of natural meteorological conditions in industrial premises and workplaces, climatic conditions must be created that are safe for humans and most favorable for performing work.

Under microclimate industrial premises are understood as the meteorological conditions of the internal environment of the premises, which are determined by the combinations of temperature, humidity, air velocity and thermal radiation acting on the human body.

Microclimate indicators should ensure the preservation of the thermal balance of a person with the environment and the maintenance of an optimal or acceptable thermal state of the body.

The indicators characterizing the microclimate in industrial premises are:

air temperature,

surface temperature (the surface temperature of enclosing structures, devices, process equipment is taken into account),

air humidity,

air speed,

thermal irradiation (in the presence of sources of radiant heat).

The sanitary rules establish hygienic requirements for the indicators of the microclimate of workplaces in industrial premises, taking into account:

intensity of energy consumption of the worker.

Based on the intensity of the total energy consumption of the body in kcal / h (W), work is divided into categories (SanPiN 2.2.548-96 "Hygienic requirements for the microclimate of industrial premises"):

Category IIa includes work with an intensity of energy consumption of 151-200 kcal / h, associated with constant walking, moving small items (up to 1 kg) in a standing or sitting position and requiring a certain physical exertion.

Category II b includes work with an intensity of energy consumption of 201-250 kcal / h, associated with walking, moving and carrying heavy loads (up to 10 kg) and accompanied by moderate physical stress.

Category III includes work with an intensity of more than 250 kcal / h, associated with constant movement, moving and carrying significant (over 10 kg) weights and requiring great physical effort;

time to complete the work;

periods of the year:

warm period of the year - characterized by an average daily temperature of the outside air above + 10С о;

the cold period of the year is characterized by an average daily temperature of the outside air equal to + 10 ° C and below.

Microclimate assessment

The assessment of the microclimate is carried out on the basis of measurements of its parameters at all places of stay of the employee during the shift and comparison with the SanPiN 2.2.4.548-96 standards in terms of:

temperature,

air humidity,

air speed,

thermal radiation.

The air temperature in industrial premises is measured at several points at workplaces at different times at a height of 1.3-1.5 m from the floor and no closer than 1 m from heating devices and external walls.

Mercury thermometers are usually used for measurements above 0 ° C, and alcohol thermometers - below 0 ° C. To measure air temperature under conditions of thermal radiation, a paired thermometer is used: one thermometer with a blackened surface of the tank with mercury, the other with silver coating. A thermograph is used to record temperature over time. Relative humidity is measured with psychrometers and hygrometers. The simplest static psychrometer (August psychrometer), consisting of 2 thermometers - dry and wet.

For more accurate measurements, an aspiration psychrometer (Assmann psychrometer) is used - a dry and wet thermometer with a built-in fan. Based on the readings of wet and dry thermometers, relative humidity is determined from the tables. A hygrograph is used to record changes in humidity over time.

The speed of air movement is measured by anemometers: vane anemometers are used from 0.4 to 10 m/s, cup anemometers are used from 1 to 35 m/s. Electric anemometers are used to measure low velocities less than 0.4 m/s. The intensity of thermal radiation is measured by actinometers, the action of which is based on the absorption of radiant energy and its transformation into thermal energy, the amount of which is recorded in various ways.

If the measured parameters comply with the requirements of SanPiN 2.2.4.548-96, then the working conditions in terms of microclimate indicators are characterized as optimal (grade 1) or acceptable (grade 2).

Optimal microclimatic conditions - provide a general and local feeling of thermal comfort during an 8-hour work shift, do not cause deviations in health status, create prerequisites for a high level of performance and are preferred in the workplace.

The microclimate of the room is the state of its internal environment, which has a direct impact on the human body. The administration of trade and public catering organizations, whether it be a cafe, restaurant, buffet, bar or canteen, in order to increase efficiency, reduce fatigue and preserve the health of its employees, is obliged to bring their workplaces in accordance with SanPiN 2.2.4.548-96 “Hygienic requirements for the microclimate of production premises” and provide comfortable and safe working conditions.

In accordance with this regulatory document, environmental conditions are divided into optimal and permissible. Optimal microclimatic conditions are distinguished by the fact that they provide complete comfort to the thermal and functional state of the human body during working hours.

Permissible microclimatic conditions are established according to the criteria for the permissible functional state of a person for the period of the working day. They are not as comfortable as optimal, but do not cause damage or any other health problems.

In practice, it often happens that in industrial premises, in particular in bakeries, hot shops of public catering establishments, where, due to technological requirements, the air temperature in the working area (at the level of the worker’s face) can reach 30-40ºС and higher, it is impossible to establish only optimal, but also acceptable standard values. In this case, the microclimate conditions must be considered as harmful and dangerous. Working in such conditions can lead to overheating of the body up to the violation of the thermal balance of the body, which does not exclude heat stroke and other serious consequences.

One of important indicators characterizing the state of the microclimate - the speed of air movement. It affects the distribution of harmful substances in the room. Air currents can spread them throughout the room, transfer dust from a settled state to a suspended one. The hygienically justified speed of air movement increases with an increase in its temperature and should be 0.1-0.2 m/s at a relative humidity of 40-60%. So, with an increase in air temperature, it is necessary to create conditions for a corresponding increase in the speed of its movement.

If the speed of air movement with a sharp increase in its temperature is not increased, this has a very adverse effect on the human body. The main reason for low air speeds, as a rule, is imperfect or insufficiently efficient systems. supply and exhaust ventilation.

Another important factor microclimate - the impact of thermal (infrared) radiation, that is, the process of propagation of radiant energy in the form of electromagnetic oscillations, on the body. The higher the temperature of the heated surface, the shorter the length of the emitted wave, which easily penetrates inside and heats the human body.

In catering establishments, workers may be adversely affected by hot cooker surfaces.

Great importance air humidity also plays a role, which affects the thermoregulation of the body. High humidity (more than 85%) makes it difficult, and low (below 20%) causes drying of the mucous membranes.

A significant improvement in the microclimate of industrial premises of public catering enterprises is facilitated by their equipping with modern specialized technological equipment, which has thermal insulation and emits significantly less radiant heat to the outside.

Along with this, well-thought-out layout of workplaces, organization of additional breaks for staff (without increasing the length of the working day), availability of showers, use of overalls, installation of air conditioners, and so on are important.

The well-being of employees of public catering enterprises is one of the important factors in the chain of relationships between management, staff, and consumers.

In accordance with SP 2.3.6.1079-01 "Sanitary and epidemiological requirements for public catering organizations, the production and handling of food products and food raw materials in them", we present below the indicators of the microclimate of public catering premises.