Achieving acceptable risk means... Basic Principles of Life Safety - GN1204: Life Safety - Business Informatics

Basic principles of risk theory

The risk is:

frequency of danger occurrence or

quantitative assessment of danger, the ratio of the number of certain adverse consequences to their possible number for a certain period

When defining a risk, it is necessary to indicate the class of consequences, i.e. answer the question “risk of what?”

Individual, social and acceptable risks

Individual risk– characterizes the danger of a certain type for an individual.

Social risk – risk for a group of people, the relationship between the frequency of events and the number of people affected.

People react sharply to rare events with a large number of one-time victims. At that time, frequent events in which a few or small groups of people die do not cause such tension. Every day, 40-50 thousand people die at work, and in the country as a whole, more than 1 million people lose their lives. According to this information, it is less impressive than the death of 5-10 people in one accident or conflict.

Quantification of risk and hazards

In practice, it may be necessary to make a financial valuation of human life for the safety of people. For example, “How much money needs to be spent to save a human life.” According to foreign studies, human life is estimated from 650 thousand to 7 million US dollars.

There are 4 methodological approaches to determining risk:

1. Engineering, based on statistics, frequency calculation, probabilistic safety analysis, construction of hazard trees;

2. Model, based on the construction of models of the impact of harmful factors on an individual, social, professional groups, etc. These methods are based on calculations for which data are not always available;

3. Expert, when the probability of various events is determined based on a survey of experienced specialists, i.e. experts;

4. Sociological, based on a population survey.

The listed methods reflect different aspects of risk, so they must be used in combination.

Acceptable (acceptable) risk

Traditional safety technology is based on a categorical imperative - to ensure safety and prevent any accidents. As practice shows, such a concept is inadequate to the laws of the technosphere. The requirements of absolute safety, captivating with their humanity, can turn into a tragedy for people because dangers can be realized in the form of injuries or diseases in the case where the zone of danger formation ( noxosphere) intersects with the zone of human activity ( homosphere).

Expected (predicted) risk – the product of the frequency of occurrence of a specific hazard and the product of the probability of a person being in the risk zone.

Acceptable risk – This is such a low level of mortality, injury or disability of people that does not affect the economic performance of an enterprise, industry or state.

Acceptable risk is determined by the impossibility of creating an absolutely safe activity (technological process). This risk combines technical, economic, social, political aspects and represents a compromise between the level of security and the ability to achieve it.

Motivated(reasonable ) and unmotivated(unfounded) risk. In the event of accidents or fires, when saving people, equipment, and structures, a person has to take a motivated risk. If workers are unwilling to comply with the safety requirements of technological processes and use personal protective equipment, they take unmotivated risks, usually leading to injuries and accidents at work.

It is impossible to ensure zero risk in existing systems.

The modern world has rejected the concept of acceptable risk, the essence of which is the desire for as little security as society can accept in a given period of time.

Risk management

How to improve security? This is the main issue in the theory and practice of security. Obviously, for this purpose, funds can be spent in three areas:

a) improvement of technical systems and facilities;

b) personnel training;

c) emergency response.

It is difficult to determine a priori the ratio of investments in each area. Special analysis using specific data and conditions is required. The conclusions may be quite unexpected.

The transition to risk opens up fundamentally new opportunities for increasing the security of the technosphere. Economic methods of risk management are added to technical, organizational, and administrative ones. The latter include: insurance, monetary compensation for damage, risk payments, etc.

Experts consider it advisable to introduce risk quotas by law. Valid data are required to calculate risk. The urgent need for data is now recognized worldwide at national and international levels. A carefully reasoned development of a database and data banks and their implementation in the conditions of an enterprise and region are necessary.

Risk management is based on a methodology for comparing costs and benefits obtained from risk reduction.

Hazard Analysis Methods

Sequence of Hazard Study

Stage 1 - preliminary hazard analysis.

Step 1. Identify sources of danger.

Step 2. Identify parts of the system that may cause these hazards.

Step 3. Enter restrictions on the analysis, i.e. eliminate hazards that will not be studied.

Stage 2- identifying the sequence of dangerous situations, constructing a tree of events and hazards.

Stage 3– analysis of consequences.

When studying hazards it is used

System Analysis – this is a set of methodological tools used to prepare and justify decisions on complex problems, in this case security.

System - it is a set of interconnected components interacting with each other in such a way that a certain result “goal” is achieved.

The components (elements, components) of a system are understood not only as material objects, but also as relationships and connections. Any working machine is an example technical systems, a system of which a person is one of the elements is called ergatic. An example of an ergatic system: “man - machine - environment”, etc. Generally speaking, any subject can be presented as a systemic education.

The principle of systematicity considers phenomena in their mutual connection, as an integral set or complex. The goal or result that the system produces is called system-forming element. For example, such a systemic phenomenon as combustion (fire) is possible in the presence of the following components: a flammable substance - an oxidizer - an ignition source. By excluding at least one of the named components, we destroy the system.

Systems have qualities that the elements that form them do not have. This is the most important property of the system, called emergence, lies, essentially, at the basis of analysis in general and security problems, in particular, the methodological status of system analysis is unusual: it intertwines elements of theory and practice, more strictly formalized methods are combined with intuition and personal experience, with heuristic techniques. The purpose of a system safety analysis is to identify the causes that influence the occurrence of undesirable events (accidents, disasters, fires, injuries, etc.) and to develop preventive measures that reduce the likelihood of their occurrence.

“Tree of causes and dangers” as a system

Any danger is realized due to some reason or several reasons. Without reasons there are no real dangers. Therefore, preventing or protecting against hazards is based on knowledge of the causes. There are cause-and-effect relationships between realized hazards and causes; the realization of danger is a consequence of some cause(s), which, in turn, is a consequence of another cause. Thus, causes and dangers form hierarchical, valuable structures or systems. The graphical representation of such dependencies is somewhat reminiscent of a branching tree. In foreign literature devoted to the analysis of facility safety, terms such as “cause tree, failure tree, hazard tree, event tree.” In trees under construction, as a rule, there are branches of causes and branches of dangers. Separating these branches is impractical and sometimes impossible. Therefore, it is more accurate to call the graphical images obtained during the safety analysis process “cause and hazard trees.”

A priori and a posteriori methods

Safety analysis can be carried out a priori or a posteriori, i.e. before or after an undesirable event. In both cases, the method used can be forward or backward.

A priori analysis

The researcher selects such undesirable events that are potentially possible for a given system and tries to compile a set of different situations that could lead to their occurrence.

Post hoc analysis

Executed after unwanted events have already occurred. The purpose of this analysis is to develop recommendations for the future.

These analyzes complement each other.

Direct method consists of studying the causes in order to foresee the consequences.

At reverse method consequences are analyzed to determine the causes, i.e. analysis begins with the crowning event.

The ultimate goal is always the same – preventing unwanted events. Having the probability and frequency of occurrence of primary events, you can move from bottom to top the probability of the crowning event.

The traditional approach to ensuring safety during the operation of technical systems and technologies is based on the concept of “absolute safety”. That is, the implementation of all protective measures that are practically feasible. As practice shows, such a concept is not adequate to the laws of the technosphere. These laws are probabilistic in nature, and absolute safety is achieved only in systems devoid of stored energy. The requirement of absolute safety, captivating with its humanity, turns into a tragedy for people, because it is impossible to ensure zero risk in existing systems, and a person must be focused on the possibility of a dangerous situation arising, i.e. focused on the corresponding risk.

The modern world has rejected the concept of absolute security and has come to the concept of “acceptable” (tolerable) risk. That is, if it is impossible to create absolutely safe technologies and ensure absolute safety, then, obviously, one should strive to achieve at least a level of risk that society can tolerate at a given time. Due to these circumstances, in industrialized countries, starting from the late 70s - early 80s. In safety research, a transition has begun from the concept of “absolute” safety to the concept of “acceptable” risk. The degree of implementation of this concept in practice today varies in different countries and in some of them it has already been introduced into legislation. For example, in the Netherlands, this concept was adopted by the country's parliament as a state law in 1985. According to it, the probability of death within a year for an individual from dangers associated with the technosphere is more than 10 -6 is considered unacceptable, and less than 10 -8 is negligible. The “acceptable” level of risk is selected in the range of 10 -6 -10 -8 per year, based on economic and social reasons. For comparison, a person's risk of death of 10 -6 corresponds to the risk he is exposed to during a 100 km car ride, or a 650 km plane flight, or if he smokes 3/4 of a cigarette, or for 15 minutes. engages in mountaineering, etc.

In the Netherlands, when planning industrial activities, along with

Rice. 1.11.. Construction of individual risk zones for a hazardous enterprise (a) and a transport route (b) along which dangerous goods are transported: 1 - equal risk contours; 2, 3, 4, 5 - zone of extremely high, high, acceptable and low risk, respectively.

Geographical, economic and political maps use risk maps for the territory of the country. In these conditions, in order to build an industrial enterprise and put it into operation, designers need to quantify the level of risk of its operation and prove to government agencies that this risk is acceptable. When licensing a new large industrial enterprise, it is also required to provide a topographic map of the risk to which a person will be exposed in the area where this enterprise is located. This map should indicate closed curves of equal risk, each of which corresponds to the following numerical values ​​of the probability of death of an individual during the year: 10 -4, 10 -5, 10 -6, 10 -7 (Fig. 1.11.). Requirements of the same kind are presented to existing enterprises.

Experts try to define risk comprehensively. Individual risk, social risk and risk to ecosystems are taken into account. The first is set by the probability of death of an individual, the second by the ratio between the number of people who could die in one accident and the probability of such an accident, and the third by the percentage of biological species in the ecosystem that will be affected by harmful effects. Not only events leading to immediate death are considered, but also factors that have long-term consequences - for example, the use of pesticides in agriculture or environmental pollution. Complex sets of computer programs have been developed that can calculate the probability of an accident at an enterprise, determine the magnitude and nature of hazardous emissions, take into account meteorological conditions, terrain, location of roads and populated areas, and ultimately construct a risk distribution map.
There is a level of risk that can be considered negligible. If the risk from any object does not exceed this level, no
There is no point in taking further measures to improve safety, since this will require significant costs, and people and the environment will still be exposed to almost the same risks due to other factors. On the other hand, there is a level of maximum acceptable risk that cannot be exceeded, whatever the costs. Between these two levels lies the area in which it is necessary to reduce risk, finding a compromise between social benefits and financial losses associated with increased safety.

The decision about what level of risk is considered acceptable and what is not is not technical, but political in nature and is largely determined by the economic capabilities of the country. Thus, the government and parliament of the Netherlands have legally established such levels. The maximum acceptable level of individual risk is considered to be 10 -6 per year. In other words, the probability of a person dying within a year should not exceed one in a million. An individual risk of 10 -8 per year is considered negligible. For factors that lead to long-term dangerous consequences and do not have a threshold of action, the same standards are adopted. If such factors only affect exceeding a threshold (for example, the maximum permissible concentration of a harmful substance), then the maximum acceptable level of risk corresponds to the threshold. The maximum acceptable level of risk for ecosystems is considered to be one at which 5% of biogeocenosis species may suffer.

Two concrete examples of how such norms work in practice. The Dutch company General Electric Plastics has applied for permission to expand production at one of its factories. Approximately 600 tons of chlorine per week were transported to this plant by rail, and phosgene was used as an intermediate reagent. Residents of a village located 600 meters away objected to such permission because they feared an increased risk of disaster. Experts carried out calculations, and it turned out that the contribution of phosgene to the overall risk created by the plant is very small. But the expansion of the plant inevitably led to an increase in the volume of storage and reloading of chlorine, as a result of which a significant part of the village could end up in an area where the risk exceeded 10 -7. A rather unexpected way out of this situation was found: in order to make the plant safer, it was necessary not only to expand it, but also to start our own production of chlorine. Then the threat associated with the transportation and storage of this poisonous gas would disappear, and the overall safety of the enterprise would even increase. This solution suited both local authorities and company executives.

Another case occurred in the southeast of Holland, where a large chemical enterprise is located, which produces, among other things, up to half a million tons of ammonia and acrylonitrite per year and is located only 200 m from the nearest villages. When local authorities proposed a plan for developing the area between the village and the enterprise, according to the existing rules, an analysis of the level of risk in this area was carried out. There were about 35 different objects on the plant territory, 10 of which were the main contributors to the overall threat. Each of them has been carefully studied. It unexpectedly turned out that many attitudes that were previously considered very dangerous do not actually play the role that was attributed to them. But the danger associated with ammonia storage facilities was underestimated. It turned out that part of the new development falls into a high-risk area. The experts made two recommendations: the plant management take measures to reduce the risk, and local authorities limit construction in areas adjacent to the plant. Residents of the villages enthusiastically accepted the first part of the recommendations and the second with indignation. After discussion in parliament, it was decided this time to allow construction in an area where the risk does not exceed 10 -6, but in the future to focus on the line where the risk is 10 -8, that is, negligible.

Of course, the Netherlands should be considered as an example of a country where probabilistic methods are most widely used in practical activities to ensure the safety of the population from risk during the operation of industrial facilities. In other countries, the extent to which the concept of “acceptable” risk is used in legislation is more limited, but in all these countries there is a trend towards increasing its application (see Table 1.7). For example, in Germany, the concept of “acceptable” risk is the basic one on which the scientific foundations in the field of security are developed. The results obtained are used to improve safety and minimize risk, rather than to achieve public acceptance of a particular technology.

The key to establishing acceptable risk is the idea proposed by Farmer. The point was to establish a random relationship between the average amount of radioactive leakage into the atmosphere from a nuclear reactor and the probability (average frequency per year) of such an event occurring.

An example of the use of such diagrams is the graph (Fig. 1.12.), in which similar dependencies are used to compare the dangers of nuclear power plants and other phenomena - both the technosphere and the forces of nature. Such graphs are called “F/N - diagram”.

The graph with the horizontal axis N - “number of accidents” and the vertical axis F - “frequency of events” (Fig. 1.13.) has the same meaning.

Table 1.7.

Risk acceptability criteria in five countries

In this way, a limiting curve of the frequency of emergency events (undesirable consequences) is determined, which can be used primarily for comparing hazards and as input data by designers and safety specialists. The curve is considered to separate the upper area of ​​unacceptably high risk from the area of ​​acceptable risk located below and to the left of the curve. The curve can thus be used as a safety criterion that defines the upper limit of the acceptable probability.

From Fig. 1.12 and 1.13 it is clear that the frequency and magnitude of the risk associated with natural disasters usually significantly exceed the threats associated with the operation of equipment. In Fig. 1.14. the economic consequences of damage caused by natural disasters and technical disasters are compared.

Since the limits of justifiable risk are difficult to rationally justify, when solving design or operational technical problems, comparison with the risk in similar situations should be used.

From tables 1.8-1.10, as well as Fig. 1.12. it can be seen that the risk of death exists at a level of 10 -7 or higher per person per year. Thus, when designing and operating technical devices, a risk of 10 -7 people/year can be accepted as acceptable under the following conditions:

· the risk problem is analyzed deeply and comprehensively;

· the analysis was carried out before decisions were made and confirmed by available data in a certain time interval;

· after the occurrence of an adverse event, the analysis and conclusion about the risk obtained on the basis of the available data do not change;

· analysis shows and control results constantly confirm that the threat cannot be reduced at justifiable costs.

The established estimate of acceptable risk should not, however, be taken as a justifiable limit; it should serve only as a basis for the relative scale of risks taken.

Rice. 1.12. Frequency and number of equipment-related accidents:

7 - total curve; 2 - total number of aircraft accidents; 3 - fires;

4 - explosions; 5 - dam breaks; 6 - emissions of harmful chemicals; 7 - aircraft accidents (without passengers); 8 - 100 nuclear reactors

The stated provisions also confirm that it is inappropriate to set a deterministic risk limit. On the contrary, more acceptable parameters seem to be the probability p ν, separating a justified risk from a conditionally justified one, and the probability p u, separating a conditionally justified risk, i.e., one that meets certain conditions, from an unjustified one.

Rice. 1.14. The amount of damage caused by technical

and natural catastrophic events: continuous line - natural disasters; dotted line - accidents

To the conditions under which the lethal risk p l in the range p v< р l ≤ р u may be accepted, the above four requirements for risk analysis apply. These requirements must be observed by the decision maker, always comparing the changing risk, for example, with increasing the maximum permissible efficiency, eliminating unfavorable situations, etc. For lethal risk, the values ​​of justified are taken p v=10 -8 and, with a large safe interval, unjustified p u= 10 -5 per person per year; these values ​​look reasonable.

Table 1.8

Probability of death

Table 1.10

Probability of death

If we are talking exclusively about the risk of material losses, the comparative method for assessing risk is beyond doubt. In this case, decisions can be made by assessing only the economic effect.

Attempts to clearly identify acceptable limits on the probability of an undesirable event occurring are hampered by the following provisions:

Such boundaries must be independent of economic costs, just as similar independence must be ensured to achieve the security of people and property;

The legislator would have to make a general decision for such boundaries, not taking into account all the specifics of individual cases;

The mere assertion that such boundaries will be respected may relieve the decision maker of the responsibility to analyze the situation further and further reduce the threat to human safety, while there may be cases where, at very little cost, the danger could be further reduced, but this opportunity is neglected , since the boundaries have already been established;

The statement that certain boundaries are maintained presupposes a qualitative unity of data, which is in fact unattainable, since danger is a multidimensional phenomenon;

Limits on acceptable risk depend on time and change with changes in the technical and economic capabilities of society.

Human practice shows that any activity is potentially dangerous. There is always a risk of danger for a person. Risk can be represented as a combination of the probability of an event with certain undesirable consequences: equipment failure, injury, illness, loss of life, material loss, etc. It is worth noting that the number of risks of death hazards both worldwide and in Ukraine is increasing.

The assessment of a person's acceptable risk level in developed countries is considered to be an individual risk of 10 ~ 6 per year. An individual risk of death of 10 ~ 4 per year is considered small. Developments for today. Blain and there is a concept of accepted (acceptable) risk, the essence of which is the desire to ensure the level of safety that society currently perceives. Comparison of individual risks of death and people c. USA and Ukraine are given in Table 11 1.1:

. Table 11. Comparison of individual risks for loss of life (by factors) c. USA and Ukraine

To do this, based on analysis and risk assessment, it is necessary to take measures to improve the management of the security system. The experience of developed countries shows that it is this method that allows one to anticipate and implement effective measures to prevent possible possible dangers. According to experts, its implementation allows, by increasing the efficiency of activities, to reduce the costs of developing and creating safe systems by 7-10 times.

In scientific research, risk management is defined as a systemic regular study of the occurrence of probable risks that threaten a person, property, interests, and activities. Risk research allows us to foresee in advance certain trends in the development of hazards, the permissibility of the parameters of their impact on humans and the environment, and as a result, as some authors note, risk accounting should be a stat and an integral component of all spheres of human life. In the dictionary, risk is defined as “the possibility of danger.” A person who is inherent in the instinct of self-preservation from birth is usually inclined to avoid risk depending on upbringing, living conditions, worldview, experience, information, but absolute safety cannot be guaranteed to any individual.

The everyday activities of specialists include such concepts as risk, risk analysis, acceptable risk, risk assessment, etc.

. Risk- is a conscious quantitative assessment of the likelihood of an event occurring with certain undesirable consequences

. Risk Analysis- this is the systematic use of information about risk, comparing it with acceptable risk, justifying rational protective measures

. Acceptable risk- is a risk that in a particular situation is considered acceptable to the level accepted in society, based on economic and social factors

. Acceptable risk- this is a risk that does not exceed the maximum permissible level on the territory of a high-risk facility or outside it

. Risk assessment- is a quantitative assessment of the impact of any hazard

The risk assessment (R) is determined by a mathematical formula as the ratio of the number of hazards (n) to the maximum possible frequency of occurrence over a specific period of time (N)

Based on risk analysis and its quantitative assessment, risk management is carried out

. Risk management is the process of making decisions and implementing measures aimed at ensuring the lowest possible risk. The goal of risk management is to anticipate (predict) risk in advance, identify factors influencing the situation, and take appropriate measures to address their respective impact.

Risk management is an interactive process with clearly defined steps:

Identifying and identifying hazards (situations) that may lead to undesirable results

Hazard risk analysis and assessment (the probability and level of risk is determined)

Monitoring and forecasting the development of hazards

Assessing the possible consequences of hazards

Development of measures and means to minimize the consequences of the hazard

. Hazard Identification- this is a quantitative and qualitative assessment of danger based on possible predictable consequences

. Monitoring and forecasting hazards consists of observation, control and anticipation of dangerous processes and phenomena of nature, technical and social spheres that are a source of danger; dynamics of their development in order to reduce the negative impact

There are long-term and short-term forecasts. Long-term predictions are far-sighted predictions of consequences, for example, in seismic areas, in areas where mudflows or landslides and flooding are possible; determination of the boundaries of damage during man-made accidents, etc. Short-term forecasts approximately determine the time of occurrence of a possible dangerous situation.

In general, all these stages can be characterized as a process of developing and justifying optimal activity programs designed to effectively implement solutions in the field of security (Figure 13):

. Figure 13 stages of risk management model

The implementation of this task involves the use of mathematical methods and models for optimizing life safety, which make it possible to clearly present the model forecast for various dangerous events and, based on this, make optimal (reasonable) decisions.

Note that risk management is widely used in many areas of scientific and production activity (technology, economics, ecology, psychology, sociology, etc.). To more clearly imagine how risk management techniques are used in practice, let’s consider an example related to the risk of danger when performing a technological operation.

For example, a carpenter intends to cut a board on a circular saw with the fence removed. This may result in a cut on your hand. Using a point scale for measuring the probability of risk and its consequences, we determine the risk category (Table 12).2:

. Table 12. Measuring the probability of risk in the workplace

From Table 12 it is clear that the level of risk increases in proportion to the increase in the likelihood of an event and the severity of the consequences. Based on this table, the risk category is established, and, if necessary, carried out with meramidiodi.

The severity of the consequences is medium (P), the probability of the event is high (A). From Table 12 we determine the risk category - (4) - high risk, unacceptable

In this case we have a high risk, unacceptable, the planned work cannot begin before the installation of the fence

An occupational risk assessment should be carried out before putting equipment or a workplace into operation, and then in the event of changes in the design of equipment, labor organization, technological process, or in the event of an accident or injury to an employee.

The employee must be familiar with the results of identification, assessment of the category of occupational risk and the measures taken to reduce it

Risk assessment can be carried out using various methods:

1. Engineering is based on the use of the theory of reliability of materials and involves identifying possible ways of failure at objects with calculation of the probability of their occurrence. In this case, the risk can be assessed not only under normal conditions of accident-free operation of objects, but also in the event of an emergency.

2. Expert. Consists of conducting a risk assessment with the involvement of experts (specialists) in a particular field

3. Statistical. Allows you to assess the risk of danger using information material (reports on dangerous situations that occurred at the object under study)

4 analog is based on the use and comparison of hazards and risk factors that have occurred in similar conditions and situations

5. Sociological. Carried out for the purpose of expert assessment of the possible occurrence of risk among workers of certain professions, specialties, and population groups

The so-called human factor plays an important role in risk management

. Human factor are the causes of risk associated with human error in the environment where its activities occur. It includes versatile elements. Among them: human behavior and his performance, design, adjustment of means of production in the workplace, decision-making to complete a production task and other elements, the main cause of accidents, catastrophes, accidents is the human factor (Figure 13) 1.3):

Fig. 13. Distribution of risk factors in the system "man - technology - environment"

Thus, the use of hazard risk assessment techniques makes it possible to justify rational measures to reduce natural, man-made, and social risks to the lowest possible level

. Control questions

1. Reveal the essence of the “person-environment” system. Name its main components

2. Define it. BZD and formulate its main tasks

4. Name and justify the main priority areas. Concepts of sustainable development of humanity in the 21st century

5. Name of the main problems of life safety and the most important conclusions

6. Describe the role of physiology, occupational psychology and hygiene in the system of knowledge about. BJD

7. Expand the concept of “danger”, “safety”, “risk”

8. Name general principles of life support

Questions for the BJD test

For FIiMO students, 2nd year

1. Life safety: objectives, basic concepts.

BZD is a system of legislative acts and norms and corresponding technical, sanitary, hygienic and organizational measures aimed at ensuring human safety, his work and preserving the environment suitable for life of the present and future generations.

The main tasks of the Belarusian Railways:

1) identification or recognition of negative impacts in the environment

2) protection from danger and prevention of their impact on humans

3) elimination of negative consequences of exposure to danger on humans

4) training in means of protection against danger

5) creating a normal or comfortable state of the living environment

Danger. Axiom about potential danger. Hazard classifications.

There are harmful and dangerous adverse factors in the environment.

-harmful under certain conditions cause illness and decreased performance

- dangerous under certain conditions, leading to traumatic injury or death

Classification of harmful and dangerous factors:

-physical (noise, vibration, workplace at height, current)

-chemical

-biological (micro and macro organisms)

-psychophysiological (neuro-psychological and physical)

Hazard is a phenomenon, process or object capable of causing harm to human health under certain conditions.

Hazard classification:

1)by the nature of occurrence:

-natural or natural

-technogenic

-anthropogenic

-biological

-social

-ecological

-mixed or combined

2) according to the likelihood of the danger affecting a person:

-potential - a general threat not related to space and time

-real - a specific threat, coordinated in space

-realized - the fact of the impact of danger on a person

3) according to the moment of occurrence:

-predictable

-spontaneous

4) according to a person’s ability to sense danger through the senses:

- felt

-imperceptible

5) by the number of people exposed to danger:

-personal

-group

-massive

6) according to the size of the impact zone

-local

-regional

-interregional

-global

Axiom about the potential danger of activity-- a statement according to which it is impossible to achieve absolute safety in any type of activity; any activity is potentially dangerous; presumption of potential danger of any type of activity.

Human interaction with the environment can vary over a very wide range: from positive to catastrophic, accompanied by loss of life and destruction. Negative impacts can be sudden, periodic or permanent in the “person-environment” system. Anything living or nonliving can be a source of danger.

The potential for danger lies in the hidden, implicit nature of its manifestation under certain, often difficult to predict, conditions. The essence of the danger is that it is possible to have such an impact on a person that leads to injury, illness, deterioration of well-being and other undesirable consequences. To a greater extent, we encounter dangers in the process of work.

Human life is potentially dangerous. The statement about the potential danger to life is an axiom that has important preventive significance when solving practical and theoretical safety issues. This axiom predetermines that all human actions and all components of the living environment, primarily technical means and technologies, in addition to positive properties and results, have the ability to generate traumatic and harmful factors.

Risk. The concept of acceptable risk. Types of risk.

, R-risk (1/year), n- number of unfavorable manifestations of danger for a certain period of time (year), N- possible number of manifestations of danger for the same period

Risk is a quantitative characteristic of the impact of a hazard on a person; risk is always a number

Risk- possible danger, the possibility of a circumstance causing social or material damage; possible loss or failure in some business .

Risk is characterized by surprise, the suddenness of the onset of a dangerous situation.

Risk includesthe following quantitative indicators: the amount of damage, the probability of a hazardous factor occurring, the uncertainty in the magnitude of both damage and probability.

Thus, quantitative risk assessment is a process of assessing the numerical values ​​of the probability and consequences of undesirable processes, phenomena, events, and therefore, the reliability of the resulting estimates must be approached with caution.

The concept of acceptable risk

The essence of the conceptacceptable (acceptable) risk consists in the desire to create such a small danger that society will perceive at a given time, based on the standard of living, socio-political and economic situation, development of science and technology,

Acceptable riskcombines technical, economic, social and political aspects and is a certain compromise between the level of security and the possibilities of achieving it. The amount of acceptable risk can be determined using the cost mechanism of the budget, which allows you to distribute the costs of society to achieve a given level of safety between the natural, man-made and social spheres. It is necessary to maintain an appropriate ratio of costs in these areas, since an imbalance in favor of one of them can cause a sharp increase in risk and its level will go beyond acceptable values.

With increasing costs for ensuring the safety of technical systems, technical risk decreases, but socio-economic risk increases. Spending excessive funds on improving the safety of technical systems, in conditions of limited funds, can cause damage to the social sphere, for example, worsening medical care.

Types of risk:

The concept of acceptable risk - 10 -6 Risk can be motivated, justified or unreasonable.

The homosphere is the sphere of human activity.

The Noxosphere is a danger zone.

-In the event of industrial accidents or fires, in order to save people, one has to take a risk that exceeds the acceptable one - the risk is considered justified (motivated).

- Unmotivated (unreasonable) risk - exceeding acceptable and arising as a result of the unwillingness of production workers to comply with safety requirements and use protective equipment. This leads to injuries and creates the preconditions for accidents at work.

Types of risks by type of hazard:

§ Technogenic risks - these are risks associated with human economic activity (for example, environmental pollution).

§ Natural risks - these are risks that do not depend on human activity (for example, an earthquake).

§ Mixed risks - these are risks that are natural events, but associated with human economic activity (for example, a landslide associated with construction work).

Types of risks by area of ​​manifestation:

§ Political risks - these are the risks of direct losses and losses or loss of profit due to unfavorable changes in the political situation in the state or actions of local authorities.

§ Social risks - these are risks associated with social crises.

§ Environmental risks - these are risks associated with the likelihood of civil liability for damage to the environment, as well as the life and health of third parties.

§ Commercial risks - these are the risks of economic losses arising in any commercial, production and economic activity. Commercial risks include financial risks (associated with financial transactions) and production risks (associated with the production of products (works, services), the implementation of any types of production activities).

§ Occupational hazards - these are risks associated with the performance of professional duties (for example, risks associated with the professional activities of doctors, notaries, etc.).

Types of risks, if foreseeable:

§ Forecasted risks - these are risks associated with the cyclical development of the economy, changes in the stages of financial market conditions, predictable development of competition, etc. The predictability of risks is relative, since forecasting with a 100% result excludes the phenomenon in question from the category of risks. For example, inflation risk, interest rate risk and some other types.

§ Unpredictable risks - these are risks characterized by complete unpredictability of manifestation. For example, force majeure risks, tax risk, etc.

According to this classification criterion, risks are also divided into regulated and unregulated within the enterprise.

Types of risks by source:

§ External (systematic or market) risk is a risk that does not depend on the activities of the enterprise. This risk arises when certain stages of the economic cycle change, financial market conditions change, and in a number of other cases that the enterprise cannot influence in its activities. This group of risks may include inflation risk, interest rate risk, currency risk, and tax risk.

§ Internal (unsystematic or specific) risk is a risk that depends on the activities of a particular enterprise. It may be associated with unqualified financial management, ineffective asset and capital structure, excessive commitment to risky (aggressive) operations with high rates of return, underestimation of business partners and other factors, the negative consequences of which can be largely prevented through effective risk management.

Types of risks according to the amount of possible damage:

§ Acceptable risk- this is a risk for which losses do not exceed the estimated amount of profit for the operation.

§ Critical risk- this is a risk for which losses do not exceed the estimated amount of gross income from the transaction.

§ Catastrophic risk- this is a risk for which losses are determined by partial or complete loss of equity capital (may be accompanied by loss of borrowed capital).

Types of risks according to the complexity of the study:

§ Simple risk characterizes a type of risk that is not divided into its individual subtypes. For example, inflation risk.

§ Complex risk characterizes the type of risk, which consists of a complex of subtypes. For example, investment risk (the risk of an investment project and the risk of a specific financial instrument).

Types of risks by financial consequences:

§ A risk that entails only economic losses has only negative consequences (loss of income or capital).

§ Risk entailing lost profits characterizes a situation when an enterprise, due to existing objective and subjective reasons, cannot carry out a planned operation (for example, if its credit rating is reduced, the enterprise cannot obtain the necessary loan).

§ A risk that entails both economic losses and additional income (« speculative financial risk"), inherent, as a rule, in speculative financial transactions (for example, the risk of implementing a real investment project, the profitability of which in the operational stage may be lower or higher than the calculated level).

Types of risks according to the nature of their manifestation over time:

§ Constant risk is typical for the entire period of the operation and is associated with the action of constant factors. For example, interest rate risk, currency risk, etc.

§ Temporary risk characterizes a risk that is permanent in nature, arising only at certain stages of a financial transaction. For example, the risk of enterprise insolvency.

Types of risks subject to insurance:

§ Insured risks- these are risks that can be transferred through external insurance to the relevant insurance organizations.

§ Uninsurable risks- these are risks for which there is no supply of appropriate insurance products on the insurance market.

The composition of the risks of these two groups under consideration is very flexible and is associated not only with the ability to predict them, but also with the effectiveness of certain types of insurance operations in specific economic conditions under the existing forms of state regulation of insurance activities.

Types of risks by frequency of occurrence:

§ High risks- these are risks that are characterized by a high frequency of damage.

§ Medium risks - these are risks characterized by an average frequency of damage.

§ Small risks - These are risks that are characterized by a low probability of damage occurring.

Acceptable risk- this is a risk that in a given situation (under given circumstances, at a given level of development of science and technology) is acceptable given existing social values. Socially acceptable risk evaluates not only and not so much the absolute values ​​of risk, taking into account many aspects of life, but rather the existing trends in the growth or reduction of risks of various conservative and new types of activities accepted by society. It is appropriate to determine acceptable risk at various levels - from the organization of an economic sector to the state.

The need to formulate the concept of acceptable (tolerable) risk is due to the impossibility of creating an absolutely safe activity (technological process). Acceptable risk combines technical, economic, social and political aspects. In practice, this is always a compromise between the level of safety achieved in society (based on indicators of mortality, morbidity, injury, disability) and the possibilities of increasing it using economic, technological, organizational and other methods. The economic opportunities for improving the safety of technical and sociotechnical systems are not unlimited. Thus, in production, by spending excessive funds on improving the safety of technical systems, it is possible to weaken the financing of social production programs (reducing the cost of purchasing workwear, medical care, sanatorium treatment, etc.).

An example of determining acceptable risk is shown in Fig. 2.2. As costs for improving equipment increase, the technical risk decreases, but the social risk increases. The total risk has a minimum at a certain ratio between investments in the technical and social spheres. This circumstance must be taken into account when choosing an acceptable risk. The approach to assessing acceptable risk is very broad. Thus, the graph presented in Fig. 2.2 is equally acceptable for both the state and a specific organization. The main thing remains in the first case the choice of an acceptable risk for society, in the second - for the organization’s staff.

Currently, taking into account international practice, it is generally accepted that the effect of man-made hazards (technical risk) should be in the range of 10 -7 - 10 -6 (deaths per person -1 · year -1), and a value of 10 -6 is the maximum acceptable level of individual risk. In Russian safety legislation, this value is used to assess fire safety and radiation safety.

Motivated (reasonable) and unmotivated (unreasonable) risk. In case of industrial accidents, fires, in order to save people affected by accidents and fires, a person has to take risks. The validity of such a risk is determined by the social need to provide assistance to injured people, official duty, and personal desire to save expensive equipment or enterprise structures from destruction.

Rice. 2.2. Determining acceptable risk

At the same time, human neglect of identified dangers leads to situations associated with individually and socially unjustified risks. Thus, the reluctance of production workers to be guided by the current process safety requirements, non-use of personal protective equipment, etc. can create an unreasonable risk, usually leading to injuries and creating the preconditions for industrial accidents.

In Fig. 2.3 shows one of the possible forms of presenting a qualitative risk assessment for various types and products of human activity.

Rice. 2.3. Qualitative risk assessments of various areas and products of human activity (public opinion of citizens and the media on the problems of risk management and risk reduction)

The figure shows that ordinary ideas about the risk of possible adverse consequences associated with human life or health include a wide variety of aspects and significantly depend on the characteristics taken into account - the duration of exposure, justification, severity of consequences, etc.