z350_422 (1).pdf

Ministry of education and science of the Russian Federation
South Ural State University
Department of Life Safety
658.382(07)
S59
A.I. Sidorov, O.A Khanzhina
TECHNOSPHERIC SAFETY
Training manual
Chelyabinsk
Publishing Center of SUSU
2018

UDC 658.382.2(075.8) + 502.34(075.8)
S59
Approved by the educational and methodical commission
of Faculty of Mechanics and Technology
Reviewers:
I.L. Kravchuk, K.B. Kuznetsov
S59
Sidorov, A.I.
Technospheric safety: training manual / A.I. Sidorov, O.A Khanzhina.
– Chelyabinsk: Publishing Center of SUSU, 2018. – 89 p.
The training manual is intended for students, undergraduates, post-
graduates studying at SUSU in English. It contains theoretical framework
of life safety, conditions are considered that determine the absence of
harmfulness to the human body, the effect of an electric current on a per-
son. Measures are provided to protect against harmful and dangerous fac-
tors.
UDC 658.382.2(075.8) + 502.34(075.8)
© Publishing Center of SUSU, 2018

3
CONTENTS
Introduction .......................................................................................................... 4
1. Theoretical basis of life safety
1.1. “Human – technology – environment” system: general description .... 6
1.2. “Human – technology – environment” model ...................................... 6
1.3. The effectiveness of the security system............................................... 9
1.4. The cost of safety system ..................................................................... 11
1.5. Dangers and their sources. Quantitative characterization
of the danger. The concept of acceptable risk...................................... 11
1.6. The concept of security. Security Systems. Principles and methods
of safety ensuring ................................................................................. 16
2. Working conditions..................................................................................... 20
2.1. The microclimate of industrial premises.............................................. 20
2.2. Harmful substances .............................................................................. 29
3. Industrial lighting
3.1. Types of industrial lighting.................................................................. 42
3.2. Sources of artificial lighting ................................................................ 47
3.3. Luminaire............................................................................................. 55
4. Noise of electrical machines
4.1. An effect of the noise on the body....................................................... 58
4.2. Noise of rotating electrical machines .................................................. 61
4.3. Noise of transformers........................................................................... 65
5. The effect of an electric current on a human body
5.1. Modern ideas about the mechanism of electrotraction........................ 70
5.2. Electrical parameters of the human body
5.2.1. General characteristics and assessments ................................... 72
5.2.2. Threshold Voltages.................................................................... 73
5.2.3. Threshold currents ..................................................................... 74
6. Technical methods of ensuring the safety of operation of electrical
installations
6.1. Safety analysis of electrical installations ............................................ 77
6.2. Protective ground................................................................................. 83
6.3. Zeroing................................................................................................. 84
6.4. Control and prevention of insulation damage ..................................... 86
Bibliographic list................................................................................................. 89

4
INTRODUCTION
The word “Safety” seems to be familiar to everyone. Safety, as the lack of
safety, parents convince their children, there is a school subject called as “Prin-
ciples of personal and social safety”, but injuries and deaths does not stop
spread. Thousands of children die and get injured in games, everyday life, kin-
dergartens and schools. Thousands of working age people die or get injured in
the streets, in the cars, at the houses, on vocation, during work activities. Practi-
cally all of them, anyway, they are warned about dangers, but for some reasons
they sincerely think that nothing can happen to them. However it happens to
them. The reason of it is the person himself. This person projects and produces
different technical devices that are insufficient safe, this person organizes tech-
nological process, in which insufficiently taken into account safety require-
ments. This person exploits equipment and does not observe safety rules. All
this, of course, different humans, but humans.
Any person lives in the world of danger. Stair treads, open windows, appli-
ances, gas device system in the kitchen – all that surrounds most people from
childhood. Bicycle, motor bicycle, car, public transport – all these things sur-
round us during all our life. Various equipment accompanies a person in his
working activity with its special dangers. How can a person get a rid of these
dangers influence?
“Health and safety” as the educational subject is for studying regularity of
appearance, development, prevention of dangers and also is for practical realiza-
tion PF dangers prevention.
The descriptive material at the dawn of modern humanity contains charac-
teristics of floods, earthquakes, volcanic eruptions, droughts, epidemics and the
behavior of people that managed to survive in these situations. Chronicles, reli-
gious treatises, other sources of literature make a point out those actions that
help to prevent diseases and the deaths of people during natural disasters.
In the latest millennium because of modern science development appeared
experimental proof of various dangers – Riemann death from lightning, chemi-
cal poisonings of people, workers’ injuries on the woods and metal working ma-
chines, on knitting looms, miners’ diseases, burns of people working with steam
engine machines, steam boiler explosions, etc. All this accrued by practice, hu-
man victims, disability and so on. Regretfully, the humanity did not have some
other ways, as discovery of something new is the beginning of uncertainty. The
first works with radioactive radium were held with bare hands, without any pro-
tection. The protection necessity was explored long after when a lot of people
suffered from radiation disease.
Facts accumulation has always obligate the scientists that were analyzing
these facts to set regularities of danger appearance, development and also to find
the ways to prevent them and to protect from them.

5
All sorts of individual and collective remedies have a meaning as protec-
tion to keep accomplish technological operations under conditions of significant
dangers, saving the workers’ lives. A lot of things have been done to prevent
professional diseases and to lower the results of their consequences. However,
there is no scientific approach to substantiation of person protection measures
from equipment in the development stage, testing and exploitations.
It was offered to use the method similar to reliability. Really, as in the reli-
ability, an injury is an accident. A person is an element of the “person- technol-
ogy” system. A person’s injury is an element’s refusal. So it was attractive to
many people that it is possible to speak about safety with, for example, 0,95 of
probability. A little detail is forgotten, firstly, we can’t carry out a test to refusal
with a person taking part in it, secondly, figure 0,95 shows that in 5 cases from
100 a person will have injury or will die. Will we find any people that want to
work with the equipment on which 5 people must die during 3 months?
Nowadays the biggest expansion gets the “risky” method, the main con-
tents of which consists of risk assessment of getting injured or dying. After re-
jecting reliability method, the theory remains under the probable assessment of
getting injured and dying with disadvantages that have been already pointed out.
The main of them is that there is no possibility to set quantitative requirements
to equipment safety, the working place and technological process to verify their
implementation at the stages of design, manufacturing, testing and operation.
“Health and safety” academic discipline is a synthetical application disci-
ple, basing on common principles of physics, on knowledge of mathematics,
physics, chemistry, biology, medicine, ecology, meteorology, geology, geophys-
ics, volcanology, seismology and other disciplines. The knowledge of mechan-
ics, structural resistance, stability theory, electrical technology, flow dynamics,
acoustics, oscillation theory, electromagnetic field theory, combustion and ex-
plosion theory and other application disciplines let identify the influence of dan-
gerous and harmful factors on human body and develop methods and means of a
person protection from them.
Together with the use of other sciences achievements, “Health and safety”
has its own object and subject matter. Object matter of “Health and safety” is a
system “human-technology-environment” and a subject matter is regularity of
dangers appearance, development and methods and protective equipment from
dangerous and harmful factors.
Consequently, it is necessary to find regularities of dangers appearance and
development and protection from them in simple, understandable and measura-
ble dangers parameters, their changes, transformation and mutual influence.
Under safety we will understand lack of danger for a person (V.I. Dahl).
However, a person can not be in abstract space. He is always connected
with technology and natural environment, in other words he is in the “human-
technology-environment” (HTE) system.

6
1. THEORETICAL BASIS OF LIFE SAFETY
1.1. “Human – technology – environment” system: general description
People are never alone; a certain environment and technology always sur-
round them. Furthermore, they are constantly interacting with technology using
it for their own purpose. Thus, the system can be defined as “a set of interrelated
elements, which interaction is aimed at achieving certain goals”. These goals are
set by man. Achievement of the goals requires appropriate technology and
means. Human interaction with technology and environment is a certain process
– therefore, it is a system-forming factor. This process is controlled by man and
always accompanied by the emergence of the relevant information.
This is the most common description of a model that defines “human –
technology – environment” system that is necessary for the analysis and synthe-
sis of the safety system. As we know, people operate with dangerous technology
all the time. This process takes place in different locations (indoors, outdoors)
and has a lot of natural factors (low temperature, rain, snow storms, rock falls,
mudflow, flood, earthquakes) that either increase or decrease various effects
from that technology. People need technology in order to achieve their goals.
Human-technology interaction – is a process that can involve only one person in
his workplace as well as several people in different places. During this interac-
tion both people and technology could be dislocated.
The functioning of technology cannot exist without the emergence of new
information: instrument readings, creation of sound, vibratory and electromag-
netic fields, temperature, etc.
This information makes possible to control the system of safety. On the ba-
sis of information on the state of security, measures are planned to improve it,
which are provided with the necessary information, human, material resources,
are promptly managed by the relevant authorities, and the results of improving
security are recorded and analyzed.
Thus, the definition of a safety system meets the requirements of system el-
ements selected from general variety. The system of safety can be considered as
a complex system that needs to be studied and analyzed.
1.2. “Human – technology – environment” model
Analysis and synthesis of the safety system are only possible with its math-
ematical description, i.e. models. However it is difficult to create such models. It
can be explained by a variety of system’s elements and its complications. There-
fore, it is necessary to use mathematical apparatus, which has a high degree of
abstraction. In this case:

7
L – amount of people;
T – amount of technology;
E – amount of environmental elements;
J – amount of information;
Y – amount of control elements.
R – interaction between these elements (functional features, preferences,
choices and other interactions). Thus we have:
LR1T, TR5L, ER9L, JR13L, YR17L,
(1.1)
LR2E, TR6E, ER10T, JR14T, YR18T,
LR3J, TR7J, ER11J, JR15E, YR19E,
LR4Y, TR8Y, ER12Y, JR16Y, YR20J.
The system of equations (1.1) is a model of the security system, if only
those of them that are related to safety are considered from all human properties,
only those that are related to the dangers or safety of a person from all the prop-
erties of nature only those that are dangerous for a person are considered, and
finally, information is only about the dangers and safety of people. Management
is initially formulated as a safety management..
Since the abstract description (1.1) does not allow us to directly analyze
and synthesize security systems, we make the following transformations. As is
known, binary relations can be decomposed into more complex ones with the
introduction of an additional variable, called the state C, if only the sets con-
nected by a relation can be divided by some criterion into at least 2 subsets. In
our case, such a division is quite possible, for example, on the basis of danger:
“dangerous - not dangerous”. In this case the system (1.1) is transformed in the
following manner:
(1.2)
Based on (1.2) it is possible to determine condition (C) for all elements of
the safety system:

8
(1.3)
(1.4)
(1.5)
(1.6)
(1.7)
(1.8)
Man’s condition depends on its own properties (health, education, disci-
pline, accuracy of actions, mindfulness) as well as on the safety of technology
and environment and the information that is given to people, how effective is se-
curity management.
The condition of technology depends on the personal safety of the techni-
cian, on how much people work safely on the machinery, on how much the envi-
ronment affects the safety of the equipment, how much information about the
technology is spread among the attendants, how the safety management system
affects the machinery.
The condition of the environment is determined by its own properties (air
dispersion, dissolution in water, congestion in lowlands, etc.) and from actions
of people to change the safe state of the environment, from how the technology
changes the safe state of the environment, from information about the safety of
the environment, from the impact of the control system on the environment.
The condition of the information also depends on its own properties (com-
plete, timeliness and reliability), as well as the influence of people on infor-
mation, the condition of technology issuing information, and the influence of
management on information.
The condition of security management depends on one's own properties-
management effectiveness and efficiency, as well as on how people are prepared
and relate to security controls, how the environment can be influenced, how in-
formation makes it possible to adopt the optimal security management solution.
The condition of the safety system (“human – technology – environment”)
determines by system properties (efficiency, accuracy) and condition of system
elements.
The cost of the safety system is obvious and determined by funds invested
in the designing, testing, manufacturing and installation of such system. The ef-
fectiveness of the system - the degree of achievement of the goal - requires a
separate consideration.
The condition of a system can be “safe” : the sources of danger cannot
lead to injury, death or disease of a person. If some sources can lead to human
health deterioration or cause death or disease, but there are no sufficient condi-
tions, i.e. other parameters do not allow damage to a person, the condition is

9
“dangerous situation” . The condition in which trauma, death or disease of
a person occurs can be called the state of an “accident” (fig. 1.1)
Fig. 1.1. Graph of system transition
from one condition to another
Originally the system is in the condition . During the process of work
parameters of the sources of danger change and system can transform into con-
dition . A transition into the state is possible only from the condition
. The duration of the can vary from years to milliseconds, but the sys-
tem must be in a dangerous situation. From the state the system can transit
into or . After the transition ends – there can be only another
system.
1.3. The effectiveness of the security system
The effectiveness of the security system depends on the formulation of its
purpose. Apparently, there can be no other goal, except for exclusions of inju-
ries, death, diseases. In this regard, a criterion for the effectiveness of the safety
system should be a criterion that assesses the absence of injuries, deaths or oc-
cupational diseases. Consequently, it must determine the possibility of the HTE
system to avoid . The possibility of getting or not getting into any state can
be estimated by probability – or
(1.9)
It is clear that the requirements for the system of this indicator cannot be
specified. Existing systems can only be evaluated and compared.
From fig. 1.1. the probability of the HTE system getting into can be
determined as follows.
will be the state “1”; as – “2”, and – “3”.
Then: – is probability of transition from “1” to “2”, – probability of
transition from “2” to “1”, and – robability of transition from “2” to “3”
(fig. 1.2).

10
Fig. 1.2. Probability transition graph
It is advisable to consider such processes using the apparatus of semi-
Markov random processes. The semi-Markov process is used because there is no
confidence in the exponentially of the distribution law of random events of tran-
sition from one state to another.
The system of algebraic equations of probabilities of getting into each state
and the normalizing equation can be written as follows:
(1.10)
Substituting in and then in we get:
(1 (1.11)
The probability of HTE system to get or avoid the condition of the accident
determines the effectiveness of the system:
(1.12)
When the probability of system transition from the state of the dangerous
situation into the safe condition equals the probability of transition from
the safe condition into the dangerous situation , the effectiveness coeffi-
cient is defined by probability and . If is greater than ,
which means the probability of returning is greater than the probability of transi-
tions in a dangerous situation, then the protection system is good.
3
2 1

11
The most interesting variable, of course, is . It is defined by infor-
mation about sources of danger, protection system, and management system.
1.4. The cost of safety system
The cost of safety system is the totality of the money resources re-
quired to ensure the absence of injuries, death or illnesses in the enterprise, in
the shop, and in the office, in the school, etc. At the same time, this means of
protection includes the cost of protection equipment, the cost of training, the
cost of signaling, the cost of automation, switches, the cost of maintaining the
control system, the cost of additional premises to accommodate equipment (for
example, computers), the cost of special clothing. All this is supplemented by
operating costs associated with equipment maintenance, its periodic inspections
and certification, as well as depreciation charges.
The increase in funds invested in the security system should be to improve
the efficiency. The qualitative dependence of the embedded in the securi-
ty system creation looks like this (fig. 1.3).
Fig. 1.3. Qualitative dependence of efficiency on invested funds
With minimal investment in organizational measures the increase in effi-
ciency is not noticeable. However, it becomes noticeable when the use of tech-
nical safety tools starts. Especially the increase in efficiency is noticeable with
the use of a comprehensive automated safety system.
1.5. Dangers and their sources. Quantitative characterization
of the danger. The concept of acceptable risk
Negative impacts in the "human-habitat" system are commonly designated
danger.
Danger – a complex of properties of human environmental factors (or a
specific situation) that can cause adverse health effects under certain exposure
conditions.

12
The source of danger can be all living and non-living and all living and
non-living can also be endangered. When analyzing dangerы, one must proceed
from the principle “everything affects everything”. Dangers do not possess an
elective property and, if they occur, negatively affect on the entire surrounding
them material environment. They are realized in the form of flows of energy,
substance and information, exist in space and time. All dangers are classified ac-
cording to a number of characteristics.
By types of sources of origin, there are natural, man-triggered and anthro-
pogenic dangers.
Natural dangers are caused by natural phenomena, climatic conditions,
land topography, etc.
The dangers created by technical means are called man-triggered, and an-
thropogenic dangers arise as a result of erroneous or unapproved actions of a
person or a group of people.
By types of flows in the vital space, the dangers are subdivided into energy,
mass and information.
At the time of origin of danger are subdivided into predictable and sponta-
neous.
By the type of impact to humans are distinguished between harmful and
traumatic.
By the objects of protection distinguish between the dangers affecting man,
the environment and material resources.
By types of impact zones, dangers are subdivided into production, house-
hold, urban (transport, etc.), emergency zones.
By probability of the impact to human and habitat, dangers are subdivided
into potential, real and realized.
Potential danger is a threat of general character not associated with space
and time of exposure. For example, the expression “noise is harmful to human”
refers only to the potential danger of noise for a person. The presence of poten-
tial dangers is reflected in the axiom: “Human life is potentially dangerous”.
This axiom determines that all human actions and all components of the envi-
ronment, primarily technical means and technologies, except to positive proper-
ties and results, have the ability to generate a danger. At the same time, any new
positive action of a person or his result inevitably leads to the emergence of new
dangers (negative factors).
The higher the transforming activity of a person, the higher the level and
number of anthropogenic and man-triggered dangers – harmful and dangerous
factors, negatively affecting the person and his environment.
Harmful factor – negative impact on a person, which leads to a deteriora-
tion of health or disease.
Dangerous factor– negative impact on a person, which leads to injury or
death. At present, the list of objectively acting man-triggered and anthropogenic

13
negative factors is significant and includes more than 100 species. The most
common and possessing sufficiently high concentrations or significant energy
levels include harmful production factors: dust and gas contamination of air,
noise, vibration, electromagnetic fields, ionizing radiation, etc. Everyday life of
a person also is accompanied many negative factors. These include polluted air,
poor-quality food, noise, electromagnetic fields of household electric appliances,
etc.
The real danger is always associated with a specific threat of impact to
human, it is coordinated in space and time. For example, a road tanker with an
inscription “flammable” moving along the road is a real danger to a person on
the roadside. As soon as the road tanker leaves at a certain distance, it will turn
into a source of potential danger to this person.
Realized danger – the fact of the impact of a real danger on a person and
(or) the habitat, leading to loss of health or to a death of a person, to material
losses. If the explosion of a road tanker led to its destruction, the death of people
and the fire of buildings, then this is a realized danger. The realized dangers are
subdivided into accidents, emergency, crash, catastrophes and natural disasters.
Accident is an event consisting of negative impact with causing damage to
human, natural or material resources.
Emergency is an event that occurs for a short time and has a high level of
negative impact on people, natural and material resources. Emergency includes
major crash, catastrophes and natural disasters.
Crash is an incident in the technical system, not accompanied by death of
people, in which the restoration of technical means is impossible or economical-
ly impractical.
Catastrophe is an incident in the technical system, accompanied by death
of people or missing people.
Natural disaster is an incident related to natural phenomena on Earth
and leading to the destruction of the biosphere, technosphere, death or loss of
human health.
Emergency situation (ES) is the state of the object, territory or water
area, usually after of emergency, which threatens life and health for a group of
people, causing material damage to the population and the economy, degrading
the natural environment.
The concept of “risk” is used to quantify the danger.
Risk is the frequency of the realization of a hazard, which can be deter-
mined by the formula
, (1.13)
where n is the number of those or other adverse consequences; N – possible
number of adverse consequences for a certain period.

14
In accordance with modern views, risk is usually interpreted as a probabil-
istic measure of the occurrence of man-triggered or natural phenomena, accom-
panied by the formation and operation of harmful factors, and social, economic,
environmental and other damage caused at the same time.
Based on the statistics of production data on the incidence of adverse ef-
fects, it is possible to predict the magnitude of possible risks. Such a forecast
makes it possible to determine the significance of each risk and to develop
measures to improve working conditions in production from a security position.
Distinguish individual, social, aggregate and other risks.
Individual risk characterizes the danger of a particular species for an indi-
vidual. Social (collective) is a risk to a group of people.
Aggregate risk is the probability of causing harm to the life or health of cit-
izens, to property, to environment, life or health of animals and plants, taking
into account the severity of this harm. Aggregate risk integrates several diverse
concepts of risk (health, ecological, property damage).
The procedure for determining the risk is very approximate. There are four
methodical approaches to the definition of risk:
1) engineering, based on statistics, frequency calculation, probabilistic safe-
ty analysis, construction of trees of danger;
2) model, based on building models of the impact of harmful factors on an
individual, social, professional groups, etc.;
3) expert, when the probability of various events is determined on the basis
of a quiz of experienced specialists, i.e. experts;
4) sociological, based on a quiz of the population.
The traditional safety technique is based on the categorical imperative: to
ensure safety, to prevent any crash. As practice shows, such a concept is inade-
quate to the laws of the technosphere. The demand for absolute security, bribing
with its humanity, can turn into a tragedy for people, because it is impossible to
ensure zero risk in existing systems. The modern world rejected the concept of
absolute security and came to the concept of acceptable (permissible) risk, the
essence of which is the desire to achieve such a small danger that society will
accept in this period of time.
Acceptable risk combines technical, economic, social and political aspects
and represents a certain compromise between the level of security and the possi-
bilities for achieving it. First of all, it must be borne in mind that the economic
opportunities for increasing the safety of technical systems are not unlimited.
Spending excessive funds on improving security can damage the social sphere,
for example, worsen medical care.
Figure 1.4 shows a simplified example of the definition of acceptable
(permissible) risk: it can be seen that with increasing security costs, the technical
risk of is decreasing, but the social and economic risk of is growing. The
total risk has a minimum at a certain ratio between investments in the technical

15
and social spheres. This circumstance should be taken into account when choos-
ing the risk with which the society is ready to put up.
Fig. 1.4. Determination of acceptable risk (RA)
Presently, there are ideas about the values of acceptable (negligible low)
and unacceptable risk: negligibly low level of individual risk of human death is
usually considered the level, equal to 10–6
per year, and unacceptable risk has a
probability of more than 10–3
.
When characterizing the public health risk caused by impact chemicals pol-
luting the environment, they are guided by the system of risk acceptance criteria.
In accordance with the criteria, the risks are classified into four ranges
(tabl. 1.1).
Table 1.1
Classification of risk levels
Range of risk
The amount
of individual risk R
1st – negligible low (acceptable) R ≤ 10–6
2nd – the maximum permissible 10–6
< R < 10–4
3rd – acceptable for professional groups and un-
acceptable for the population
10–4
< R < 10–3
4th – unacceptable for the population and for
professional groups
R ≥ 10–3
A negligible low (acceptable) range of risk (1st risk range) characterizes
such levels of risk that are perceived by all people, as negligible, not differing
Socio-economic risk RSE
Technical risk RТ
Security costs
Risk
of
death
in
a
year
RA
The total risk (RТ+RSE)

16
from ordinary, daily risks (an individual lifetime risk equal to or less than 10–6
,
corresponds to one additional case of a serious illness or death per 1 million ex-
hibited persons). Such risks do not require any additional measures to reduce
them and their levels are subject only to periodic monitoring.
The maximum permissible (2nd) range of risk corresponds to the upper
limit of acceptable risk (individual risk throughout life more than10–6
, but less
than10–4
). At this level of risk, most foreign and hygiene standards recommend-
ed by international organizations for the general population are established. For
example, for drinking water, the World Health Organization (WHO), as an ac-
ceptable risk, uses a value of10–5
, for atmospheric air – 10–4
. These levels are
subject to constant monitoring. In some cases, at such levels of risk, additional
measures may be taken to reduce them.
Acceptable for professional groups and unacceptable for the population
(3rd) range of risk – individual risk throughout life more than10–4
, but less
than10–3
. The emergence of such a risk requires the development and implemen-
tation of planned health-improving activities. The planning of measures to re-
duce risks in this case should be based on the results of a more in-depth evalua-
tion of various aspects of existing problems and determining their degree of pri-
ority in relation to other hygienic, ecological, social and economic problems on
this territory.
Unacceptable for the population and for professional groups
(4th) range of risk – individual risk throughout life, equal to or more than10–3
.
When this range of risk is reached, it is necessary to give recommendations to
the persons making decisions on conducting emergency health-improving events
to reduce risks.
When planning long-term programs, establishing regional hygienic stand-
ards, it is advisable to focus on the value of the target risk – the level of risk that
must be achieved as a result of risk management activities. In most countries, as
well as in the recommendations of WHO experts, the value of the target risk is
taken to be 10–6
.
The value of the target risk for conditions existing in populated areas in
Russia is 10–5
–10–6
.
At present, the concept of risk assessment in virtually all countries of the
world is considered as the main mechanism for the development and adoption of
managerial decisions both at the international, state or regional levels, and at the
level of individual production.
1.6. The concept of security. Security Systems.
Principles and methods of safety ensuring
All dangers are then real when they affect specific objects (protection ob-
jects). The objects of protection, like the sources of dangers, are diverse. Every

17
component of our environment can be objects of protection from dangers. The
basic desired state of the objects of protection – safe.
Security is the state of the object of protection, in which the impact on it of
all flows of substance, energy and information does not exceed the maximum
allowable values. Speaking about the realization of the state of security, it is
necessary to simultaneously consider the object of protection and the set of dan-
gers acting on it. Today there really exist the following security systems:
personal and collective security of a person in the process of his life activity;
environmental protection (biosphere);
state security;
global security.
The systems of ensuring human security is possessed of the historical prior-
ity, which at all stages of its development constantly strived to ensure comfort,
personal safety and preservation of one's health.
Principles and methods of of safety ensuring relate to private or special
methods, in contrast to the general methods inherent in dialectics and logic. The
principle is an idea, a thought, a basic position. The method is the way, the
method of achieving the goal, proceeding from the knowledge of the most gen-
eral regularity.
The principles of security can be divided into orienting, technical, organi-
zational and managerial.
The orienting principles include the principles of operator activity, human-
ization of activities, destruction, operator replacement, classification, elimina-
tion of danger, systematic approach and risk reduction.
Technical principles include the principles of blocking, vacuum treatment
evacuation, hermetic, distance protection, compression, strength, weak link,
phlegmatization and screening.
Organizational principles include the principles of time protection, infor-
mation, incompatibility, rationing, selection of personnel, consistency and ergo-
nomics.
Management principles include the principles of adequacy of control, feed-
back, responsibility, planning, incentives, management and efficiency.
Here are some examples of realization some principles.
For example, the organizational principle of rationing is the establishment
of certain parameters, the observance of which ensures the protection of a per-
son from the corresponding danger. To such parameters include MPC (maxi-
mum permissible concentrations) of harmful substances, MPE (maximum per-
missible emissions) of harmful substances, MPL (maximum permissible levels)
of harmful substances, etc.
The technical principle of a weak link is that an element is introduced into
the system (object) in question for the purpose of safety, which is designed to
perceive or react to a change in the corresponding parameter, preventing a dan-

18
gerous phenomenon. An example of the realization of this principle are rupture
membranes, fuses and other elements, the protection of various devices and
mechanisms.
The organizational principle of information is the transfer and assimilation
of information by the personnel, the realization of which provides an appropriate
level of security. Examples of realization: training, briefing, warning labels, etc.
The orienting principle of classification (categorization) consists in divid-
ing the objects into classes and categories according to the signs associated with
the dangers: sanitary protection zones, categories of production according to ex-
plosion danger, etc.
For consideration of security methods, we introduce the following defini-
tions.
The homosphere is the space (working area) where the person is in the
process of the activity under consideration.
The noxosphere is a space in which there are always or periodically appear
dangers.
The combination of the homosphere and the noxosphere is unacceptable
from the standpoint of security. In figture 1.5 it is shown that safety is provided
if these two spaces (the homosphere and the noxosphere) have no common
points.
а b c
Fig. 1.5. Three possible variants of finding in the space
of the homosphere (H) and the noxosphere (N)
If the homosphere and the noxosphere are separated in space (fig. 1.5a),
then security is ensured. In the case shown in fig. 1.5b (contact between two
spaces H and N), negative consequences for the person are already possible and
fig. 1.5c illustrates not only the possibility of negative consequences for humans,
but also allows us to estimate the probability of this event (shaded area). It fol-
lows that if these two spaces completely coincide, then an unfavorable event is
bound to happen!
Security is provided by three main methods: A, B and C.
Method A consists in the spatial and (or) temporal separation of the
homosphere and the noxosphere. This is achieved by means of remote control,
automation, robotics, etc.
Here it is necessary to note the correctness of determining the time separa-
tion of the homosphere and the noxosphere. Explain this with the example of a
N
H N
H N
H

19
traffic-controlled intersection. It would seem that the corresponding signals of
the traffic light divide the human and transport streams. We will not take into
account violators of traffic rules. Can the car break down any elements of the
control system? Can! Can anything happen to a vehicle driver who won't let him
drive? Can! Therefore, in our example, method A will be realized when the hu-
man flow along one path (different transitions), and the transport one in another
way.
Method B consists in the normalization of the noxosphere by eliminating
dangers. It is a combination of measures that protect people from noise, gas,
dust, and various means of collective protection.
Method C contains a gamut of device and means aimed at adapting a per-
son to the appropriate environment and increasing their security. This method
realization the possibilities of professional selection, training, psychological im-
pact, personal protective equipment (PPE).
In real conditions, these methods, as a rule, are used together or in various
combinations.

20
2. WORKING CONDITIONS
A person is exposed to hazards during his work activity. This activity is
carried out in a space called the production environment. The set of factors of
the production environment and the labor process that affect the working capaci-
ty and health of the employee is called the working conditions. The identifica-
tion of factors depends on the objectives of the assessment of working condi-
tions, namely: is it possible for the employee to receive an injury and (or) occu-
pational disease. Factors can be dangerous and harmful.
Dangerous production factor – a production factor, the impact of which on
the employee can lead to his injury. Some dangerous production factors that can
lead to injury to the employee are following:
• electric current of a certain strength;
• incandescent objects;
• the possibility of falling of an employee from the height or different parts
and objects;
• equipment operating under pressure exceeding atmospheric pressure;
• moving objects, mechanisms or machines, as well as their fixed elements
in the workplace (with mechanical action: gear, chain, V-belt drives, crank
mechanisms, movable tables, rotating parts, controls), etc.
A harmful production factor is a production factor, the impact of which on
an employee can lead to his illness.
2.1. The microclimate of industrial premises
Man is in constant relationship with surrounding environment. As far as
possible, he adapts to it, and in the absence of such an opportunity – adapts it
with all available means, thereby providing the conditions for his normal exist-
ence.
A working person is about one third of his time in production under the in-
fluence of the production environment, which is characterized by various fac-
tors: the microclimate of production facilities, the intensity of the technological
process, the materials and mechanisms used, etc.
The microclimate of production premises is the meteorological conditions
of the internal environment of these premises, which are determined by the
combinations of temperature, humidity, speed and motion of air and thermal ir-
radiation acting on the human body.
The microclimate indicators should ensure the preservation of the human
heat balance with the environment and the maintenance of the optimal or per-
missible thermal state of the organism.

21
The human body is called as a thermodynamic system with a high constan-
cy of the average body temperature with significantly changing conditions of in-
take and heat losses.
Throughout life, a person exists within a very limited and actively protect-
ed range of internal body temperatures. The maximum permissible limits for the
vital activity of cells ranges from 0 °C (the formation of ice crystals) to 45 °C
(thermal coagulation of intracellular proteins). However, for short periods of
time, a person can bear body temperature below 35 °C or above 41 °C.
Taking into account only those temperature differences that exist between
the surface of the ice shield of Antarctica, where the air temperature can drop to
–82.6 °C, and the jungle of the tropics, where it sometimes rises to +50 °C, it
can be assumed that a person is able to inhabit in an environment whose thermal
range exceeds 100 °C.
Consequently, the human body can produce a truly huge amount of energy
to fight the cold and heat. His body can be compared to a continuously operating
heat factory, provided with perfect physiological mechanisms of self-regulation.
To maintain the temperature of own body within these limits, a person has effec-
tive physiological reactions, with which he usually responds to sudden changes
caused by strong heating or cooling of the body. This fact provides evidence of
the tremendous adaptive capabilities of the human body developed in the course
of evolution, including with the help of modern technology: the creation of a
special microclimate in rooms, heating, air conditioning, specialized transport
systems, clothing with heating or cooling, etc. At the heart of these reactions,
caused by the need to coordinate various systems of the human body and regu-
late the processes of heat release to maintain a constant temperature of the hu-
man body, lies thermoregulation function.
The famous Russian physiologist I.P. Pavlov (1849–1936) in 1881 put for-
ward the position that the human body is divided into a core and a shell. Accord-
ing to modern concepts, the mass of the nucleus, i.e. Internal tissues and organs,
is approximately half the body weight. When a person is healthy and environ-
mental conditions do not require undue stress of his thermoregulatory systems,
the core temperature remains constant. It can to a certain extent increase with
particularly hard physical work, very intense heat or fever during the illness, and
also decrease with too much cooling. For all these states, a person's life is in
danger.
To maintain a constant temperature of the core of the human body, a heat
balance must be observed: the heat input to it and its internal production must be
balanced by the consumed heat. Under the conditions of zero thermoregulation,
the heat gain is balanced by heat losses, heat is not conserved, and body temper-
ature is maintained in an equilibrium state.
The temperature regime of the shell of the human body (2–2,5 cm thick), to
which the extremities and external tissues of the trunk belong, is different from

22
that of the internal organs. The shell is called the “thermal lock of the body”,
where heat can be concentrated or consumed without noticeable changes in the
temperature of the deep layers of the body and without harm to health. A person
lives in conditions of constant temperature of the internal parts of the body: in
order for his existence and activity to be possible, the temperature of his body
(shell) must be kept at a constant 36–37 °C.
The average limits of body temperature, in which a person remains viable
(but not workable!), are relatively small: from 25 to 43 °C. Now, a method of
significant cooling of the patient's body is used during operations: from 36 to
25 °C. In the foreign press, sensational reports are given about the survival of
people whose body temperature has dropped to lower limits. The upper and
lower pain threshold values for human skin temperature are approximately 43
and 10 °C, respectively.
Morphological studies revealed the location of the largest thermoregulatory
device in the region of the brain, known as the preoptic, or preceding, hypothal-
amus. At this point, nerve cells are located, which react both to heating (neurons
sensitive to heat) and to cooling (neurons sensitive to cold). This area dominates
the body temperature control system by accepting incoming sensory information
regarding body temperature and sending outgoing signals to the shell, muscles
and other organs participating through the autonomic nervous system in temper-
ature regulation. The human body temperature control system is similar to the
thermostatic function of a domestic thermostat, which can both heat up and cool
the room in the house. When the body temperature rises above a certain “estab-
lished” theoretical mark, a certain executive element connected with the cooling
of the organism (sweating, increasing the flow of blood to the shell of the body)
starts to act. When the body temperature falls below the “set” temperature, the
elements that are responsible for the increase in heat fluxes (diminishing blood
flow inside the body shell, laxity, trembling, etc.) are connected to the system.
However, unlike household heating and cooling appliances, the human ther-
moregulation system does not work as a simple “on-off” system. It can also be
adjusted by shut-off, depending on the adjustment characteristics.
At an air temperature of + 20 °C, the distribution of incoming heat in the
human body from the sun (or heat sources), from the atmosphere and oxidative
processes inside the human body is as follows: 31 % of its total amount is car-
ried away by moving air, 44 % is spent for radiation into the environment, 22 %
goes to evaporation from the surface of the skin, 1 % is consumed for heating
food, 1,3 % – for heating the air in the lungs and 0,7 % is lost with excreta.
The main external factors affecting human thermoregulation – the flow of
heat exchange processes by convection, radiation and vaporization, are the am-
bient temperature (t, °С), relative humidity (φ, %), air velocity (V, m/s) And
thermal radiation from hot surfaces (ts, °C, and J, W/m2
).

23
The assessment of human exposure to temperature varies depending on the
time of year, the geographic location of the area, the state of the air environ-
ment. In different temperature conditions, all items of heat consumption by the
human body have different indicators. There is an expression: “The climate en-
ters the body through the skin.”
At high temperature, the body struggles with overheating. A person is freed
from excessive heat by heat transfer to the environment through radiation, con-
vection and evaporation. To facilitate this heat exchange, two primary systems
of the actuator are activated and regulated: when the heat reflexively dilates the
skin vessels (vasodilatation of the body shell) and increases sweating.
The expansion of the vessels of the skin occurs primarily in order to trans-
fer heat from the core to the human body shell (internal heat transfer), while
sweat evaporation is an extremely effective means of cooling the blood before it
returns to the deep tissues of the human body (external heat transfer). In this
case, in order to facilitate temperature regulation, the surface blood flow in-
creases, and its volume is increased. This affects the work of the cardiovascular
system: the central blood flow decreases, the suction volume decreases. As a re-
sult, in hot conditions, the heart rate becomes higher, breathing and pulse in-
crease, blood pressure decreases, skin redness is observed, the skin temperature
rises, resulting in a greatly increased loss of heat by radiation.
In the heat regulation of human life, from 2 to 4 million exocrine sweat
glands, randomly and unevenly scattered throughout the surface of the body.
Exocrine glands secrete sweat directly on the surface of the body shell. It has a
high heat of vaporization and ideally satisfies the cooling purpose. The efficien-
cy of this cooling system is high. For example, a working person with a con-
sumption of oxygen in a volume of 2,3 liters per minute produces heat up to 640
Watts. If there was no sweating, then the temperature of the human body would
increase by 1 °C every 6–7 minutes. Cooling the body is achieved by evaporat-
ing the sweat. With an effective evaporation of about 16 g/min (a reasonable rate
of heat loss), heat release can corresponds to the norm and, as a consequence,
the internal temperature of the body will be in an equilibrium state.
Changes occurring in the body in hot weather lead to a loss of heat that is
twice bigger comparing to heat losses during cold weather. The process of evap-
oration proceeds with a large expenditure of energy: 1g of water is spent to
transfer it into steam about 600 calories of heat. The amount of sweat evaporated
from the surface of the body and, consequently, the intensity of cooling achieved
in this case depends on the work of the mechanisms of sweat secretion and the
rate of its removal from the surface of the skin. They are related in turn to how
“correctly” a person sweats, i.e. Whether the moisture is gradually and evenly
distributed on the surface of the body and whether it is able to leave it soon
enough. This process depends on both the properties of the organism and the
meteorological conditions.

24
With normal perspiration, cooling due to the evaporation effect depends on
the relationship between the pressures of the water vapor of the wet envelope
and the surrounding air. Numerous observations have established that the heat
balance of a person at rest is maintained with some difficulty already at an air
temperature of 40 °C and a relative humidity of 85 %. When these indicators are
exceeded, the state of health of most people deteriorates sharply. Thus, high
humidity and dense or waterproof clothing limit the cooling by evaporation,
while dry air, airing the body with the use of lightweight porous clothing facili-
tates evaporation. But if the work is associated with heavy physical exertion and
accompanied by excessive perspiration, cooling by evaporation may be limited
by the body's ability to sweat (no more than 1–2 l/h).
An effective strategy against body hypothermia is to try to increase the
thermal insulation of the shell of the human body, namely, to reduce the heat
output from the skin and increase the heat production. This is achieved by reduc-
ing the surface blood flow to his skin. To do this, as a result of the correspond-
ing signals of the nerve receptors and the command received from the central
nervous system, the vessels of the skin and subcutaneous tissue decrease, and at
a lower temperature or especially a sharp drop, goose skin appears – a sign that
the smooth muscles of the skin began to contract. The narrowing of the skin ves-
sels is more pronounced on the limbs of a person than on his body.
The heat costs for evaporation of sweat in such conditions fall to very small
values. The blood flow in the superficial layers of the body is weakened: its out-
flow to the internal organ takes place, because of which the difference between
the skin temperature and the ambient temperature decreases. This leads to a re-
duction in radiation – the main item of heat consumption, accounting for about
half of all its costs. In this case, the heat exchange of the body with the environ-
ment decreases in proportion to the difference in body and ambient air tempera-
tures. However, the decrease in radiation is more significant, since it is propor-
tional to the fourth degree of body temperature, hence, a small decrease in its
near the skin leads to a very significant decrease in this item of heat consump-
tion. In this way, adaptive processes can reduce the heat loss of the body to 70 %.
In the initial period of exposure to low temperatures, a decrease in the res-
piratory rate and an increase in the volume of inspiration are observed on the
human body. With prolonged action, breathing becomes irregular, the frequency
and volume of inspiration increase, the carbohydrate balance changes. In pa-
tients and unoccupied people, the work of adaptive systems is more or less dilut-
ed, so the reaction of their body to a decrease in the ambient temperature, espe-
cially when the weather changes sharply, causes a deterioration in well-being,
pain, recurrence of chronic diseases and various colds.
Subcooling can take various forms, affecting the heat balance of the whole
organism, causing a decrease in the internal temperature of the body, as well as
limbs, skin, and lungs (fig. 2.1).

25
Overcooling leads to discomfort, a violation of sensory and neuromuscular
function and eventually frostbite (fig. 2.2). A distinctive feature of the person's
reaction to cold is the fact that in the thermoregulatory reaction to cold, behavior
is much more important. For example, compared to heat in a cold environment,
a much more important role is played by what kind of clothes a person wears,
and what work it does.
Fig. 2.1. Negative consequences of hypothermia
Fig. 2.2. Dependence of the work of elements of the human body
of ambient temperature

26
Sufficient heat protection prevents undercooling. The amount of heat loss is
determined by the heat-protective properties of clothing and climatic conditions
of the environment. However, the thermal protection itself can cause undesirable
or unfavorable effects on the human body. The use of heat-shielding clothing,
shoes, gloves and hats reduces the mobility and agility of the worker. There is
such a thing as the “cost of defense”, but meaning that movement from place to
place and body movements can not happen endlessly, as they ultimately lead to
a loss of strength. One of the important directions of research in ergonomics is
the refinement of the functional capabilities of clothing to maintain heat protec-
tion from cold.
The value of the relative humidity of air shows the percentage of the
amount of water contained in a specific volume of air (at a certain temperature
and pressure) of water vapor to the amount that completely saturates this volume
before moisture falls in the form of rain drops:
(2.1)
Where Pv is the pressure of water vapor contained in air, Pa; PS – saturated
vapor pressure, depending on temperature and air pressure, Pa; – density of
water vapor contained in air, kg/m3
; is the density of saturated water vapor,
kg/m3
.
The influence of relative humidity on the well-being of a person is deter-
mined in addition to the air temperature t of the barometric pressure, the features
of the process of its breathing. The main organ of human respiration, through
which gas exchange with the environment is carried out, is the tracheobronchial
tree and a large number of pulmonary cells – the blisters (alveoli), whose walls
are penetrated by a dense network of capillary vessels. Through the walls of the
alveoli, oxygen enters the bloodstream to feed the tissues of the body. Through
them, carbon dioxide (carbon dioxide) is extracted from the blood, which is re-
leased by the use of oxygen. In addition, the pulmonary cells suck blood out of
the body for an extra amount of water. She exits from it with exhalation along
with the air.
It was experimentally established that the intensity of diffusion of oxygen
into the blood is determined by the partial pressure of oxygen in the alveolar air,
the change of which is proportional to the changes in the atmospheric pressure
of the inhaled air. According to Dalton's law, the atmospheric air pressure Pair is
determined by the sum of the partial pressures of the gases entering into it,
namely the partial pressures of carbon dioxide , oxygen , nitrogen ,
water vapor , etc. .:
+ + +… (2.2)

27
The change in the composition and amount of water vapor, as well as the
change in other components contained in the inspired air, leads to a change in
the intensity of diffusion of oxygen into the blood. A person's well-being re-
mains at a relative humidity of 40–60 %. At high temperatures (over 30 °C), the
increased humidity of the air has an adverse effect on the person's thermal
health, since almost all the heat released is released to the environment when the
perspiration evaporates, which does not evaporate but drips from the skin and
does not provide the necessary heat transfer.
The data of physiologists and bioclimatologists confirm that it is easier to
tolerate a fever in a person with more dry air. But everything has a limit: if the
relative humidity is less than 20 %, the evaporation from the surface of the mu-
cous membranes of the human respiratory tract is so great that they begin to dry
out, which causes unpleasant sensations of dryness in the throat and nose, crack-
ing of the lips, and also reduces the protective action of these membranes as fil-
ters, blocking the entry into the body of dust and microbes.
The influence of the speed of air flow on a person can sometimes be esti-
mated as positive, and in some cases as negative. The point, first of all, in the
intensity of air movement, temperature and humidity of the environment.
At low air temperature, the speed of air movement has a cooling effect on
the human body, carrying away the layers of air that are adhering to the body
and pressing new portions of cold to it (fig. 2.3).
In addition, the humidity of air has a noticeable effect. Thus, at an air tem-
perature close to zero and high humidity, a sharp increase in the heat transfer of
the organism occurs due to additional costs not only for heating the body, but
also for drying out the open surfaces of the body and clothing. If the speed of the
air is high, the warmth is still worse, since the wind keeps warm and dried layers
of air from the body and catches up new portions of moist and cold air, which
increases the process of further cooling the body.
In many branches of modern production, most of the personnel work in
conditions related to the thermal impact from the process equipment: furnaces,
boilers, pipelines, etc. For example, in hot workshops of industrial enterprises,
most of the technological processes take place at temperatures much higher than
the ambient temperature. Heated surfaces radiate into the space streams of radi-
ant energy. At a temperature of up to 500 °C, thermal (infrared) rays with wave-
length λ from 1...2 mm to 0,74 μm are radiated from the heated surface, and at a
higher temperature, along with the increase in infrared radiation (IR radiation),
visible light and ultraviolet rays are appeared.

28
Fig. 2.3. Dependence of the state of the human body
from negative values of air temperature and wind force
Infrared rays have mainly thermal radiation on the body, as a result of
which biochemical shifts occur in the body, oxygen saturation of blood decreas-
es, venous pressure decreases, blood flow slows down, cardiovascular and nerv-
ous system activity is disrupted.
By the nature of the impact on the human body, infrared rays are divided
into short-wave rays with a wavelength of 0,76...1,5 μm and long-wavelength
rays with a wavelength of more than 1,5 μm. The thermal radiation of the short-
wave range penetrates deep into the tissues and warms them, causing rapid fa-
tigue, decreased attention, increased sweating, and with prolonged irradiation –
heat stroke. Long-wave rays do not penetrate deeply in the tissue and are ab-
sorbed mainly in the epidermis of the skin. They can cause skin and eye burns.
The most frequent and severe eye damage due to infrared rays is the cataract of
the eye.
To characterize the thermal irradiation, the concepts of the intensity of
thermal irradiation JE, W/m2
, – the radiant flux per unit of irradiated area, and
the exposure dose (DOE), W · h, defined as
, (2.3)
where is the intensity of thermal irradiation, W/m2
, S is the irradiated sur-
face area of the body, m2
, τ is the duration of irradiation for the work shift, h.

29
When determining the irradiated surface of the body, it is necessary to take
into account the proportion of each part of the body, %: head and neck – 9, chest
and abdomen – 16, back – 18, hands – 18, legs – 39.
Thermal irradiation is limited by the thermal pain threshold of the skin. So,
the intensity of up to 350 W/m2
does not cause unpleasant sensation, at a dose of
1050 W/m2
after 3–5 minutes on the surface of the skin there is unpleasant burn-
ing, the skin temperature rises by 8–10° C, and at a dose equal to 3500 W/m2
,
after a few seconds, possible burns.
In addition to direct exposure to humans, radiant heat heats the surrounding
structures. These secondary sources give off the warmth to the environment by
radiation and convection, as a result of which the air temperature inside the
room rises.
2.2. Harmful substances
Atmospheric air, getting into production premises, can change its composi-
tion, polluting with impurities of harmful substances: gases, vapors, dust,
formed during production. Getting into the human body during breathing, as
well as through the skin or esophagus, such substances can have harmful effects.
The deterioration of human health, caused by poor indoor air quality, may result
in the appearance of a set of acute and chronic symptoms or in the form of a va-
riety of specific diseases (fig. 2.4).
Currently, about 7 million chemicals and compounds are known. 500–1000
new chemical compounds and mixtures appear on the international market every
year. About 60 thousand substances are used in human activities.
The entry into the air of industrial premises of a harmful substance depends
on the technological process, the raw materials used, and also on intermediate
and final products.
Depending on the aggregate state, harmful substances belong to different
groups of hazardous and harmful production factors. For example, aerosols
(dusts) of predominantly fibrogenic action refer to physical hazardous and harm-
ful production factors, vapors and (or) gases refer to chemical hazardous and
harmful production factors.
There are four classes of hazardous substances:
• substances of the 1st class – extremely hazardous harmful substances;
• substances of the 2nd class – highly hazardous substances;
• substances of the 3rd class – moderately hazardous substances;
• substances of the 4th class – slightly hazardous substances.
The hazard class of a harmful substance is established by toxicological in-
dicators.

30
Fig.2.4 Symptoms and diseases associated with indoor air quality
Given the specific effects on the human body, chemically hazardous and
harmful production factors are classified:
• by the nature of the effect on the human body – on toxic, irritating, sensi-
tizing, carcinogenic, mutagenic factors and factors affecting human reproductive
function;
• the way of penetration into the human body – the factors that act through
the respiratory system, the gastrointestinal tract, skin and mucous membranes.
Toxic substances are substances, poisons, which, entering the body in
small amounts, then enter into chemical or physico-chemical interaction with
tissues and, under certain conditions, cause a violation of health. Although al-
most any substance can possess toxic properties, it is customary to treat poisons
only those substances that exhibit their harmful effects under normal conditions
and in relatively small amounts. Industrial poisons relate to the category of
harmful substances and are subject to the study of toxicology. The action of poi-
sonous substances can be manifested in acute and chronic poisonings.
Acute poisoning is a disease that occurs immediately after the action of the
poison. Acute poisonings are characterized by a short-term effect of poisons (no
more than one shift) and the introduction of harmful substances into the body in

31
relatively large quantities. Acute poisoning causes such industrial poisons as
prussic acid, carbon disulfide, etc. Acute poisonings are investigated and ac-
counted for as accidents.
For industrial conditions in the case of non-compliance with safety rules,
chronic poisoning is more typical as a result of prolonged systematic penetra-
tion of the poison into the body in small quantities. In this case, poisoning oc-
curs either as a result of the gradual accumulation (material cumulation) of the
poison in the body, or due to the gradual accumulation of changes caused by the
ingestion of a poison (functionally cumulative). The action of the same poison is
different for chronic and acute poisoning. For example, in acute poisoning with
benzene, the nervous system is mainly affected, while the chronic system is af-
fected by the hematopoiesis system.
Toxic effect of harmful substances. It is characterized by indicators of
toxicometry, according to which substances are classified into poisons with gen-
eral toxic effects and toxins of selective toxicity (tab. 2.1).
The indicators of toxicometry and criteria for toxicity of harmful substanc-
es are quantitative indicators of toxicity and the hazard of harmful substances.
The degree of toxic effect of poison depends on its structure, physical state at
the time of exposure, the duration of ingestion, and the body's response. The
gender and age of employees working at the enterprise, as well as their individu-
al sensitivity, are important.
Industrial poisons can cause not only specific poisoning, but also contribute
to the occurrence of diseases such as upper respiratory catarrh, tuberculosis,
kidney disease, cardiovascular system, etc.
Irritant harmful substances are substances that irritate the mucous mem-
branes of the respiratory tract, eyes, lungs, skin. These include bromine, chlo-
rine, fluorine, ammonia, acids, alkalis, nitrogen oxides, hydrogen sulphide, etc.
Table 2.1
Toxicological classification of harmful substances
Toxic effect Toxic substances
General information
Nervous-paralytic action
(bronchospasm, choking,
convulsions and paralysis)
Phosphoroorganic insecticides
(chlorophos, carbofos, nicotine,
poisonous substances, etc.)
Skin-resorptive action (local
inflammatory and necrotic changes
in combination with general toxic
resorptive phenomena)
Dichloroethane, hexochlorane, acetic
essence, arsenic and its compounds,
mercury (mercuric chloride)
General toxic effects (hypoxic
convulsions, coma, cerebral edema,
paralysis)
Cyanic acid and its derivatives,
carbon monoxide, alcohol and its
surrogates, poisonous substances

32
The rest of the tab. 2.1
Toxic effect Toxic substances
Asphyxiant (toxic pulmonary edema)
Oxides of nitrogen, poisonous
substances
Tear and irritant effect (irritation
of the outer mucous membranes)
Vapors of strong acids and alkalis,
chloroFigrin, poisonous substances
PsychotroFig action (violation of
mental activity, consciousness)
Drugs, atropine
Electoral
Cardiac with a predominant
cardiac effect
Vegetable poisons, soybean metals:
barium, potassium, cobalt, cadmium,
etc.
Nervous, causing a violation
of predominantly mental activity
Carbon monoxide, organophosphorus
compounds, etc.
Blood Aniline and its derivatives, nitrites,
arsenic hydrogen, etc.
Hepatic Chlorinated hydrocarbons, phenols,
aldehydes, etc.
Kidney
Heavy metal compounds, etc.
Pulmonary Oxides of nitrogen, ozone, phosgene,
etc.
Sensitizing substances are various harmful substances, which cause allergic
diseases. These include formaldehyde, solvents and varnishes based on nitro
compounds, beryllium and its compounds, cane-foil, detergent synthetic agents.
Carcinogenic, mutagenic and effects that affect the reproductive function
are related to the long-term effects of the effects of chemical compounds on the
human body. This is a specific action that manifests itself after years and even
decades. Carcinogenic effects of harmful substances usually cause malignant
tumors (aromatic hydrocarbons, benzene, coal tar pitches and pitch, asbestos,
chromium, nickel, etc.). Substances affecting reproductive (fertile) function (sty-
rene, mercury, lead, benzopyrene, gasoline, manganese in welding aerosols, ra-
dioactive isotopes, etc.). In addition, the appearance of various effects in the
next generation is noted.
Many production processes are accompanied by a dust factor. In the air in-
haled by a person, dust particles with a diameter up to 20 μm can be contained.
Particles with a diameter of 10–20 μm are retained in the upper parts of the res-
piratory tract. In the alveoli of the lungs, particles with a diameter of up to 5 μm
are mostly retained.
The reasons for the release of dust can be very diverse. Dust can form dur-
ing mechanical processing of brittle metals, grinding, polishing, packaging and
packaging. These types of dust formation are primary. In the conditions of pro-

33
duction, secondary dust formation may occur, for example, during ventilation,
cleaning of premises, movements of people.
Dust is a dispersed phase of solid substances formed during their crushing,
grinding, and also in the condensation of metal vapors and nonmetals in air.
Dusts suspended in the air form aerosols, a cluster of settled dust – aerogels.
The harmful effect of dust on the human body depends on the amount of
inhaled dust, the degree of its dispersion, the shape of dust particles, its chemical
composition and solubility. According to the nature of the effect on the body,
industrial dusts are divided into general toxic and irritating.
General toxic dust (lead, arsenic, beryllium, chromium trioxide, etc.), dis-
solving in the biological fluid of the body, act as a poison introduced into the
body and cause acute or chronic poisoning.
Irritant dusts do not have the ability to dissolve well in body fluids, but can
affect the body by irritating the skin, eyes, ears, gums, causing allergic reactions.
A large group of aerosols that do not have significant toxicity, differs from
other harmful substances by fibrogenic action on the human body. Getting into
the respiratory system, the substances of this group cause atrophy or hypertro-
phy of the mucosa of the upper respiratory tract, and being trapped in the lungs,
lead to the development of connective tissue in the air-exchange zone and scar-
ring (fibrosis) of the lungs. Occupational diseases associated with exposure to
aerosols, pneumoconiosis and pneumosclerosis, chronic dust bronchitis are the
second most frequent among occupational diseases in Russia.
Pneumoconiosis is the general name of a number of lung diseases, which,
depending on the type of inhaled dust, are divided into silicoses (silicic dust),
silicates (salts of silicic acid), anthracoses (coal dust), metallocanioses (metal
dust), etc. In pneumoconiosis, anatomical degeneration of the connective tissue
of the lungs (fibrosis) is observed, leading to a restriction of their respiratory
surface and changes in the entire body.
Employees of many enterprises are usually exposed to the combined effect
of several harmful substances.
A combined action is a simultaneous or sequential action on the human
body of several harmful substances with the same pathway. Depending on the
effects of toxicity, additive, potentiated, antagonistic and independent types of
combined action of toxic substances are distinguished.
The additive effect of several harmful substances is the total effect of the
mixture, equal to the sum of the effects of the active components. Additivity is
characteristic for substances of unidirectional action, when the components of
the mixture affect the same body systems.
With the simultaneous content of several harmful substances in the air of a
unidirectional impact (according to the conclusion of the sanitary inspection
bodies), the sum of the ratios of the actual concentrations of each of them (K1,
K2, ..., Kn) in air to their MPC1, MPC2, ..., MPCn should not exceed units, so as

34
(2.4)
An example of additivity is the narcotic effect of a mixture of hydrocarbons
(benzene and isopropylbenzene), nitrogen oxides and carbon, amino compounds
and carbon monoxide, nitro compound and carbon monoxide.
With a potentiated action (synergism), the components of the mixture act
so that one substance enhances the effect of the other. The effect of combined
action with synergism is more additive, which is taken into account when ana-
lyzing the hygienic situation in specific manufacturing conditions. However, this
phenomenon does not have a quantitative assessment. Potentiation is noted with
the combined action of sulfur dioxide and chlorine, alcohol is exacerbated by the
risk of poisoning with mercury, aniline. The phenomenon of potentiation is pos-
sible only in case of acute poisoning.
The antagonistic action is the effect of a combined action of the least ex-
pected. The components of the mixture act so that one substance weakens the
effect of the other. In this case, the effect is less additive. An example of antago-
nistic action is the interaction between eserin and atropine.
With an independent action, the combined effect does not differ from the
isolated action of each toxic substance separately.
Activities to reduce exposure to harmful substances. Such measures
primarily include engineering and technical measures aimed at replacing obso-
lete and introducing new technological processes and equipment that contribute
to the elimination of unfavorable working conditions. Promising directions here
are automation, mechanization and remote control of production processes that
take place in unfavorable for the human body of the microclimate, accompanied
by the release of harmful substances:
• use of stamping instead of forging works, replacement of annular furnaces
for drying molds and rods in tunnel foundry;
• welding in a vacuum prevents the entry of toxic gases and aerosols into
the air;
• coloring in the electrostatic field significantly reduces the release of sol-
vent vapors and colorful aerosols into the work area;
• application of pneumatic transport in loading and unloading operations in
the technological processes, mechanization during cleaning of parts, blanks al-
lows to reduce the length of stay of workers working under unfavorable working
conditions;
• tightness of the equipment, namely tightly fitted doors, dampers, blocking
of the closing of technological openings with equipment operation – all this sig-
nificantly reduces the release of heat and harmful substances from open sources.
Hygienic and sanitary measures are aimed at creating harmless working
conditions in the current production. These include: hygienic standardization,

35
monitoring of the air environment, compliance with hygiene requirements in the
face of increased danger of poison (emergency situations, repair work), the use
of protective equipment, ventilation, the prevention of poisoning through appro-
priate planning and decoration of buildings, sanitary briefing of workers.
Hygienic standardization means the elimination and restriction of the con-
tent of harmful substances in the raw materials and in the final products of pro-
duction (lead in printing inks, arsenic in the composition of acids and metals,
etc.).
Depending on the features of the technology, equipment, the degree of cur-
rent-toxicity of the processed products, the corresponding types of planning, fin-
ishing the premises and location of the equipment are also used. For example,
equipment that is a source of dangerous poisonous substances, isolates from
working by the introduction of remote control of such equipment. To avoid the
sorption of toxic substances, materials that do not absorb toxic substances (ce-
ramic tiles, plastics, etc.) are used by windows, wooden window fences, floors.
Planning issues are closely connected with the device of general exchange venti-
lation, which allows creating excessive pressure in the premises in order to pre-
vent the penetration of substances from neighboring rooms, and also to dilute
harmful emissions to safe concentrations. In some cases, an effective measure is
the installation of local exhaust ventilation, trapping harmful substances at the
sites of their isolation.
Medical and preventive measures are aimed at preventing the occurrence of
industrial poisoning and diseases. They are: compulsory preliminary upon ad-
mission to work and following periodic medical examinations, organization of
additional and special food; vitaminization; ultraviolet irradiation of workers;
alkaline inhalation, respiratory gymnastics. Those working with toxic substances
undergo special sanitary instruction.
Legislative measures. In accordance with the Russian labor legislation, the
limitation of working hours, the provision of additional leave, the earlier age of
retirement, and the increase in the wage rates of official salaries are provided for
persons working with harmful substances. In a number of industries, the em-
ployment of women and adolescents is not allowed. The registration and regis-
tration of occupational poisoning are obligatory. Accepted norms for MPC of
harmful substances in the air of the working area are mandatory for the admin-
istration of enterprises, institutions, organizations.
Individual respiratory protection. If the application of engineering and
technical measures does not lead to a reduction in the concentration of harmful
substances, as well as in the case of temporary stay of a worker in a hazardous
zone of toxic fumes, gases, individual protective equipment is used.
Respiratory protection means are designed to protect workers from harmful
substances (aerosols, gases, vapors, dust) present in the ambient air during vari-
ous technological processes. When selecting personal respiratory protection

36
equipment (PPE), you need to know what substances you have to work with,
what is the concentration of substances, in what state they are (in the form of
gases, dust, aerosols), is there a danger of oxygen hunger, how long have to
work in dangerous conditions, what are the physical loads in the process of
work.
There are two types of respiratory protection, based on two different meth-
ods for providing individual protection of the respiratory organs from the effects
of the ambient air: filtering (air purification) and insulating (supplying clean air
or oxygen-based breathing mixtures from a source).
The filtering RPEs supply air to the respiration zone. For the purpose of fil-
tering RPE, depending on the aggregate state of harmful substances from which
protection is necessary, are divided into three classes: anti-aerosol; anti-gas; an-
ti-gas aerosol (combined).
According to the design, the filtering PPE is subdivided:
• with filtering face without valves (fig. 2.5, a);
• with a filter face with valves (fig. 2.5, b);
• with the front part of insulating materials with filter systems, valves and
without them (fig. 2.5, c, d).
The advantages of filtering agents are their ease, convenience, simplicity in
handling; they are securely fixed in the working position, do not interfere with
the freedom of movement of the worker. The disadvantages of these remedies
are the difficulty of breathing due to the resistance of the filter; limited operation
with the use of a filter in time (if there is no filter mask, which is equipped with
blowing), in addition, filters have a limited shelf life.
To protect the respiratory organs from toxic vapors and gases, use filter
masks, respirators, panoramic masks, helmet masks.
Filter respirators and respirators can only be used if there is sufficient oxy-
gen in the ambient air (at least 18 % by volume) and with a limited known con-
tent of harmful substances. They can not be used for work in hard-to-reach
rooms of small volume, in closed and semi-enclosed spaces (tanks, pipes, pipes,
etc.), as well as in various emergency situations where the amount of harmful
substances in the ambient air is unknown. In such cases, insulating breathing ap-
paratus is used.
Isolating RPE (fig. 2.5, e) provides air to the breathing zone from special
containers or from clean space located outside the working area.
Isolation protectors are used in the presence of oxygen deficiency in in-
haled air, air pollution at high concentrations or when the concentration of con-
tamination is unknown (for example, in case of emergency release of chemical
or radioactive substances, in case of fire, etc.) if heavy work when breathing
through the filtering equipment is difficult due to the resistance of the filter, to
work in particularly dangerous conditions (in isolated volumes, in the repair of
heating furnaces, gas networks, etc.).

37
а)
b)
c) d) e)
Fig. 2.5. Filtering personal protective equipment for respiratory system
The range of insulating PPE is extensive and constantly expanding. Cur-
rently, there are means to provide comprehensive protection of a person from
dangerous and harmful factors, while simultaneously protecting the organs of
sight, hearing, breathing, and protecting individual parts of the human body.

38
Activities and means of normalizing the air environment of industrial
premises and workplaces
To prevent adverse effects of the microclimate, protective measures should
be used. For example, the use of a local air conditioning system, air rains, com-
pensation for the adverse effects of one parameter of the microclimate by chang-
ing another, overalls and other personal protective equipment, rest and heating,
regulation of the working day, increase in length of leave, work,
The means of protecting workers, depending on the nature of their applica-
tion, fall into two categories:
• means of collective protection;
• individual protection means.
Collective means of normalizing the air environment of industrial premises
and workplaces include the following devices:
• air conditioning;
• heating;
• automatic control and signaling;
• air deodorization.
The localization of harmful factors includes devices to reduce the adverse
effects of heat and cold. This, for example, various heat-shielding means: heat
insulation, heat shields, air cramps, air curtains and oases.
The choice of thermal protection means should be carried out taking into
account the requirements of ergonomics, technical aesthetics, safety for this pro-
cess or type of work and feasibility study. Heat-shielding means should be easy
to manufacture and install, convenient for maintenance, do not interfere with
checking, cleaning, lubricating aggregates, have the necessary strength, have
minimum operating costs, provide irradiation of equipment no higher than
308 K (35 °C) at a source temperature of up to 373 K (100 °C) and no higher
than 318 K (45 °C) at a temperature inside the source above 373 K (100 °C).
Thermal insulation of the surfaces of radiation sources (ovens, vessels,
pipelines with hot gases and liquids) reduces the temperature of the radiating
surface and reduces both the total heat release and radiation.
Heat shields are used to localize sources of clean heat, reduce irradiance in
the workplace and reduce the temperature of the surfaces surrounding the work-
place. The attenuation of the heat flow behind the screen is due to its absorptive
and reflective capacity. Depending on what screen capacity is more expressive,
heat-reflecting, heat-absorbing and heat-dissipating screens are distinguished. In
terms of transparency, heat shields are divided into three classes:
opaque – metal water-cooled and lined asbestos, alfoly and aluminum;
translucent – made of metal mesh, chain curtains, made of glass, reinforced
metal mesh (all these screens can be watered with a water film);
transparent – from various glasses (silicate, quartz and organic, colorless,
colored and metallized) and film water curtains.

39
Air strangulation – the air supply in the form of an air jet directed to the
workplace is used when exposed to working heat radiation of 0,35 kW/m2
and
more, and also 0,175 to 0,35 kW/m2
with the area of radiating surfaces within
More than 0,2 m2
. Air strangulation is also arranged for production processes
with the release of harmful gases or vapors and when it is impossible to arrange
local shelters.
The cooling effect of air shuffling depends on the difference in the temper-
atures of the body of the worker and the air flow, and also on the speed of air
flow around the cooled body. To provide the workplace with specified tempera-
tures and air velocities, the air flow axis is directed to the human chest horizon-
tally or at an angle of 45°, and to ensure acceptable concentrations of harmful
substances, it is sent to the respiratory zone horizontally or from above at an an-
gle of 45°.
The flow of air from the striking nozzle should have a uniform speed and
the same temperature as possible. The distance from the edge of the stripping
pipe to the workplace must be at least 1 m. The minimum diameter of the nozzle
is assumed to be 0,3 m; at fixed work stations, the estimated width of the work-
ing platform is assumed equal to 1 m.
At an irradiation intensity above 2,1 kW/m2
, an air shower can not provide
the necessary cooling. In this case, it is necessary to provide thermal insulation
or shielding. For periodic cooling of the workers, they arrange radiation booths
and rest rooms.
Air curtains are designed to protect against the entry of cold air into the
building through the building openings necessary for the passage of personnel
(gates, doors, etc.). The air curtain represents an air jet directed at an angle to
meet the cold flow of air. It plays the role of an air gate, reducing the flow of air
through the openings. Air curtains must be arranged:
• at permanently open openings in the external walls of premises, as well as
at the gates and openings in external walls that do not have tambours and open
more than five times or less than 40 minutes per shift in areas with a calculated
temperature of the outside air – 15 °C or lower;
• exterior doors of public lobbies and administrative buildings – depending
on the estimated temperature of outdoor air and the number of people passing
through the door within 1 hour;
• exterior doors, gates and openings of rooms with wet conditions;
• on special technological requirements and justifications.
The amount and temperature of the air for the air curtain is determined by
calculation.
Several basic schemes of air curtains are used (fig. 2.6). The beams with
the bottom feed (fig. 2.6, a) are the most economical in air consumption and are
recommended in the case when the temperature is not allowed to drop near
openings. For apertures of small width, the circuit shown in fig. 2.6, b. The

40
scheme with a two-sided lateral direction of the jets (fig. 2.6, c) is used in cases
where it is possible to stop the transport at the gate.
Fig. 2.6. Schemes of air curtains:
a – with the lower air supply; b – one-sided; c – bilateral
Air oases are designed to improve the meteorological conditions of work,
usually to rest on a limited area. For this, the schemes of cabs with light mobile
partitions have been developed, which are filled with air with the appropriate pa-
rameters.
Measures for the prevention of adverse effects of heat and cold should pro-
vide for the prevention of cooling of production facilities, the use of PPE, the
selection of a rational mode of work and recreation.
For example, special clothing used as PPE should be air-and waterproof,
have a comfortable cut (fig. 2.7).
Heat-insulating properties of clothes that reduce heat loss of the body, it is
appreciated in terms of “Clos” (from the English clothes-clothes). 1 Clo in ther-
mal units is equal to 0,18 °C·m2·h/kcal. Such properties, for example, has a
normal husband's suit (insulating properties of a light summer dress – 0,5 Clos, a
demi-season coat –2...2.5 Clos, winter Arctic clothing – 4...6 Clos).
The materials used are such fabrics as cotton, linen, coarse woolen cloth.
Special protective clothing includes sheepskin coats, coats, short coats,
sheepskin coats, dressing gowns, overalls, overalls, waistcoats, etc.
The rational mode of work and rest is developed with reference to concrete
working conditions. Frequent short breaks are more effective for maintaining
performance than rare, but prolonged.

41
Fig. 2.7. Warm suit
In conditions of microclimate with the air temperature at workplaces above
and below the permissible values, it is recommended to regulate the duration of
work within the working shift, as well as the general working conditions.

42
3. INDUSTRIAL LIGHTING
3.1. Types of industrial lighting
Light is important for a person, because it provides a visual perception of a
person's environment. Most of the information that people receive through the
senses supplies light – about 80 %. It allows you to evaluate the shape, color and
perspective of objects that surround a person in everyday life. The quality of
visual information is largely determined by the conditions of visual work. One
should not forget that such elements of a person's state of health as mood and
degree of fatigue depend on the lighting and color of surrounding objects.
The purpose of industrial lighting is to provide normal visual conditions for
the performance of the relevant work in the production room. Unsatisfactory or-
ganization of the industrial lighting system can lead to errors in the performance
of assigned operations by the employee, as well as accidents related to difficul-
ties in recognizing certain items or determining the degree of danger associated
with servicing machines, vehicles, containers with corrosive substances and etc.
The damage to vision associated with deficiencies in the lighting system is,
unfortunately, a frequent occurrence. Due to the ability of the eyesight to adapt
to insufficient lighting, this problem is not given the necessary attention.
According to the type of light source, production lighting can be of three
types (fig. 3.1):
 natural – the source of light is the sun (direct or diffuse scattered light
from the heavenly dome);
 artificial – artificial light sources;
 combined – inadequate natural light is supplemented with artificial light-
ing.
Fig. 3.1. Types of industrial lighting
Industrial lighting
Daylight Artificial
lighting
Combined
lighting
Working
Emergenc
y
Security
Attendant

43
Natural lighting has both positive and negative sides. Solar radiation
strongly affects the skin, internal organs and tissues and, above all, the central
nervous system. This influence is not limited to the time when a person is in the
sun, but continues after he leaves the room or the night falls. Physicians call it
reflex.
The action of sunlight begins with an effect on the skin. The non-protected
human skin reflects between 20 and 40 % of the visible and invisible infrared
rays that have fallen on it (20 % reflect the skin of a tanned person, and 40 %
reflect the most unmarketed, white skin). The absorbed part (60...65 %) of radi-
ant energy penetrates the outer skin and affects the deeper layers of the body.
Ultraviolet and some infrared rays reflect the skin to a lesser extent and are
more strongly absorbed by the horny, coarser layer of the skin.
With solar fasting, the skin becomes pale, cold and lethargic; it is poorly
supplied with nutrients and oxygen, blood and lymph are less circulating in it,
the products of decay – slags and the poisoning of the body with waste sub-
stances – begin to flow poorly. In addition, the blood capillaries are made brittle,
in connection with which the tendency of the human body to hemorrhage in-
creases.
Those people who are experiencing solar starvation, there are painful, un-
pleasant metamorphosis, affecting both the sphere of the psyche and the physical
state. First of all, there are disorders of the nervous system: the deteriorating
memory and sleep, increased irritability in some and indifference to everything
going on, confusion in others. Since calcium metabolism deterioration (occur-
rence of difficulties in the assimilation of dietary calcium and phosphorous,
which continue to be output from the body, and hence these fabrics depletion
occurs necessary substances) begin to collapse hard а teeth, increased bone fra-
gility. With prolonged solar fasting, mental abilities and performance decrease,
very quickly fatigue and irritation occur, mobility decreases, and the ability to
fight against microbes falling into the organism deteriorates (immunity decreas-
es). A person experiencing solar starvation, often falls ill with colds and other
infectious diseases, which are protracted. In these cases, fractures, cuts and any
injuries slowly and badly heal. There is a tendency for pustular diseases in those
who did not suffer from this before, and the chronic diseases worsen in those
who already have them, the inflammatory processes are more severe, which is
associated with an increase in the permeability of the walls of the vessels, and
the propensity to edema increases.
Given the degree of beneficial effect of natural light on the human body,
occupational health requires the maximum use of natural light. It is absent only
where it is contraindicated by the technological conditions of production, for ex-
ample, when storing photosensitive chemicals and products.
According to the design, natural light is subdivided:

44
 on the side, carried out through the window openings one or two-sided
(fig. 3.2, a, b);
 upper, when light enters the room through aeration or anti-aircraft lights,
openings in the ceilings (fig. 3.2, c);
 combined, when added to the top lighting side (fig. 3.2, d).
Fig. 3.2. Kinds of natural light in dependence from design
The most effective combined natural lighting, providing a more even dis-
tribution of illumination inside the production room.
Unfortunately, under natural lighting, the lighting changes greatly during
the day, because the duration of the light day depends on the time of the year,
the lighting also changes with changing weather conditions, possibly shadowing
or dazzling in bright light.
Artificial lighting allows you to eliminate the shortcomings of natural light
and provide an optimal light mode. Artificial lighting is divided into working,
emergency, security and duty.
Work lighting is mandatory for all rooms, buildings, as well as areas of
open spaces. It serves to ensure normal working conditions, people's passage,
transportation.
Emergency lighting is subdivided, in turn, into security lighting and evacu-
ation.
Security lighting is provided in cases where the disabling of the working il-
lumination and the associated disruption of maintenance of equipment and
mechanisms can cause:
 explosion, fire, poisoning people;
 prolonged disruption of the process;
 disruption of the operation of facilities such as power plants, radio and
television transmissions and communication centers, dispatch centers, pumping

45
installations for water supply, sewerage and heating, ventilation and air condi-
tioning for industrial premises where work stoppage is unacceptable, etc .;
 violation of the regime of work of children's institutions, regardless of
the number of children in them.
Evacuation lighting in rooms or workplaces outside buildings should in-
clude:
 in places that are dangerous for people;
 Aisles and staircases used to evacuate people (if the number of evacuated
more than 50 people);
 on the main passages of industrial premises, in which more than 50 peo-
ple work;
 on staircases of residential buildings with a height of six floors and
more;
 in industrial premises without natural light, etc.
Emergency light sources can be switched on at the same time as the main
lights and permanently lit or switched on automatically only when the normal
power supply is interrupted.
Security lighting (in the absence of special technical means of protection) is
provided along the boundaries of the territories protected at night.
Attendant lighting is foreseen for lighting of premises during non-working
hours. If necessary, some of the work lamps or emergency lighting can be used
for standby lighting.
Artificial lighting by design can be: general and combined.
General lighting – lighting, in which the lamps are placed in the upper zone
of the room. The luminaries can be located evenly – general uniform illumina-
tion (fig. 3.3, a) or with regard to the arrangement of equipment or workplaces -
the general localized illumination (fig. 3.3, b).
Combined lighting – lighting, in which the local is added to the general,
concentrating the light flux directly at the workplace (fig. 3.4). Only local light-
ing can not be used!
Fig. 3.3. Types of artificial general lighting:
а – general evenly lighting; b – general localized lighting

46
Fig. 3.4. Combined artificial light
There are also special types of artificial lighting, for example, bactericidal
and erythemic. Erythemic lamps are used to irradiate people in order to replen-
ish solar insufficiency in the northern regions and in the middle band (in the ab-
sence or lack of natural light in the workplace, for example, in mines, metro,
etc.).
Bactericidal lamps are used to suppress the vital activity of pathogenic mi-
croorganisms, including those responsible for the spread by airborne pathways
of dangerous infectious diseases such as tuberculosis, diphtheria, measles, influ-
enza, smallpox, etc., and are used in industrial premises, as well as for disinfec-
tion of drinking water and food.
Combined lighting – lighting, in which natural and artificial light is simul-
taneously used at daylight. At the same time, under the conditions of visual
work, natural lighting is constantly supplemented by artificial lighting. It can be
used, for example, inside multi-storey buildings of large width, in single-storey
multi-span buildings with spans of large width, etc.
Conditions of visual comfort in the workplace. Visual comfort in the
workplace can be felt by observing the following.
1. The level of illumination in the workplace must correspond to the nature
of the work performed. Usually, the more difficult the visual work, the higher
should be the average level of illumination. Nevertheless, the excessively high
illumination of the working area can make the eyes tired.
2. Uniform distribution of illumination on working surfaces and within the
surrounding space. This condition is due to the fact that a constant movement in
the unevenly illuminated zones leads to fatigue of the eyes, in addition to adapt-
ing to a sharp change in the illumination of the eye takes some time, during
which a person can not see the surrounding space and respond in a timely man-
ner to possible dangerous situations. For this reason, one local lighting is not
applied.

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