**Hazard Matrix Application in Health, Safety and Environmental Management Risk Evaluation**

Assed Haddad, Erick Galante, Rafaell Caldas and Claudia Morgado *Federal University of Rio de Janeiro Brazil* 

### **1. Introduction**

28 Risk Management for the Future – Theory and Cases

St.Vincent, M., Chicoine, D.&Beaugrand, S. (1998). Validation of a participatory ergonomic

Standards Australia & Standards New Zealand (2004). *Risk management, AS/NZS 4360/2004*

Theys, J. (1991). Conquete de la securite, gestion des risques, Paris: L'Harmattan, p.279-298. U.S. Department of Army (2010). Safety Mishap Risk Management, DA-PAM 385-30, Retrieved August, 2011 from http://www.apd.army.mil/pdffiles/p385\_30.pdf Walters, D, & Frick, K. (2000). Worker participation and the management of occupational

Walters, D., Nichols, T., Connor, J., Tasiran, A. C. & Cam, S. (2005). *The role and effectiveness of* 

Zohar, D. (1980). Safety climate in industrial organizations: theoretical and applied

Zohar, D. & Luria, G., (2004). Climate as a social-cognitive construction of supervisory safety

implications. *Journal of Applied Psychology* 65/1980, pp. 96–102.

Available from *https://infostore.saiglobal.com/store* 

Amsterdam.

89/2004, pp.322–333.

approach in industries in the electrical sector. *Int J Ind Ergonomics*, vol. 21, pp. 11-21.

health and safety: reinforcing or conflicting strategies? Cht.3, in *Systematic occupational health and safety management; perspectives on an international development*  (ed by Frick, K., Jensen, P., L., Quinlan, M., & Wilthagen, T.), Pergamon,

*safety representatives in influencing workplace health and safety,* Health and Safety Executive, Retrieved April 2011 from http://hse.gov.uk.research/rrhtm/rr363.htm

practices: scripts as proxy of behavior patterns. *Journal of Applied Psychology*

In occupational safety one of the most complicated and harder to achieve goals is to prioritize actions towards risk prevention and mitigation. There are several methodologies to do that. Some of them are expensive; demand some extensive structure for its application and so on. Some others are either weak in results or lack technical or scientific basis. (Haddad *et al*, 2008). The research presented in this chapter emerged in between these methodologies for being not expensive and requiring resources, most of the time, already available in a company's documentation.

More specifically, this chapter focuses on the development and usage of a risk assessment methodology called Hazard Matrix (HM) and its application in Health, Safety and Environmental Management (HSE). The HM is a prioritization methodology suitable to be used in the analysis phase of a risk management program. The application of HM in HSE is a very powerful methodology to highlight critical hazards and sectors/areas in a business unit or company under study.

We will present and explore the HM concept, features, relevance and implementation, under the scope of a risk management process. In order to achieve this, the chapter will follow this sequence, organized in sections:


The case studies presented come from two different types of industries, in order to demonstrate the comprehensive application of HM and details. Although the methodology lacks a refined or complex mathematical structure, we can refine the presented approach and develop other implementations leading to a high detailed usage. Here we refrain to do that; this is something for future work.

#### **2. HSE aims and structure**

Basically, HSE deals with the anticipation and recognition, analysis, evaluation, treatment and communication of hazards and treats in the occupational safety aspect of any company,

Hazard Matrix Application in Health, Safety and Environmental Management Risk Evaluation 31

*NOTE 3 Risk is often characterized by reference to potential events and consequences), or a* 

*NOTE 4 Risk is often expressed in terms of a combination of the consequences of an event (including* 

*NOTE 5 Uncertainty is the state, even partial, of deficiency of information related to, understanding* 

The concept of risk indicates that it relates to activities or tasks to be performed, being intimately related to a human behavior or environment. As an example, a fuel, such as gasoline, isolated from its context, does not present any level of risk by itself. However, when this fuel is considered to be handled at an environment where sources of ignition are present, for example, dealing with gasoline becomes a hazardous activity. The associated risk will vary according to the behavior of the handler and environmental where it is done. As stated by (Ciocoiu and Dobrea 2010) "even apparently insignificant risks have the

Due to the very nature of risk, it is present in almost every activity, job or task performed in the modern world. The accelerating pace of business, globalization, the financial crisis, all contribute to the growing number and complexity of risks and to the greater responsibility for managing risks on an enterprise-wide scale (Ciocoiu and Dobrea, 2010). This leads to the need of managing occupational risks ahead in order to assure minimum casualties and optimum performance. However, the risk is also a very complex entity, which directs to

It is commonly accepted that a proper method for assessing and managing risks pass through decomposing the "risk" in its independent variables: *frequency, severity,* and

*Risk = f (frequency, severity, scenario)*  Decomposing the risk in independent variables and further analyzing each variable is the core method presented in the MIL STD 882 for preliminary Hazard analysis. This concept has proved to be successful , since it is still used by many standards, including the forth review of MIL STD 882 (United States, 2003), OHSAS 18.001:2007 (OHSAS, 2007) and ISO

Before human's development of *risk management* process and the clear concept of *system safety*, the common technique used to deal with risk was mainly based on a *trial and error* approach. This culture led mankind to fix problems only after its consequences were observed at the already designed running system. In opposition, the idea of minimizing risks until acceptable levels by trying to predict the occurrence of accidents and taking measures in order to avoid them is widely diffused nowadays. This approach characterizes

Risk management can be defined as the collection of culture, processes and structures that are directed towards realizing potential opportunities whilst managing adverse effects (Australia, 2004). In this context, it is a complex process and can be understood as a

systematic application of management policies, procedures and practices.

potential, as they interact with other events and conditions, to cause great damage. "

*changes in circumstances) and the associated likelihood of occurrence.* 

*or knowledge of an event, its consequence, or likelihood"* 

difficulties when understanding and managing.

31.000:2009 (ISO, 2009)

**3.1 The risk management process** 

the concept of risk management.

*scenario*. Therefore, the dependent variable "Risk" can be written as:

*combination of these.* 

and by an expanded or more comprehensive perspective, to all surrounding environments. HSE is becoming increasingly important, as well as demanded, in any company's effort towards sustainability and legal adequacy. It is becoming part of its regular operations and is commonly required by regulatory bodies, clients and society.

In order to organize a HSE Program one needs to develop and structure (ISO 14.001:2007, 2007) a set of activities in a close relation with a Risk Management Program (ISO 31.000:2009, 2009). Determination of scope and objectives are necessary for the establishment of such a Risk Management Program. In this phase, each step of this management process must be defined, as well as its expected results. After that, the mapping of all organization's processes and also their interactions must be performed (the ones that interfere in risk management). On this phase of the HSE effort, all activities, operations and the relations between them must be clearly identified, as they represent potential sources of hazard. Moreover, in order to achieve enough knowledge to underlie adequate action of HSE process, data must be collected from the activities and operations, about its **Processes** (inputs and outputs), its **People** who work there, and generally about the **Organization** itself.

After data collection and the processes mapping are done, the management process is able to perform a **Hazard Mapping and Identification**, which consists in identification, localization and classification of the hazards involved in each process activities of the organization. This classification is performed according to two aspects: type of hazard existent, such as physical, chemical, biological etc., and the severity of its impact. The second one is traduced mathematically by weights that can be represented in a boarding selection.

After these entire actions have been performed one can establish the necessary set of information in order to develop the HM (Haddad *et al*, 2008) application in the next stage. With the sequential implementation of the concepts and tools listed one should be able to apply these concepts, use the HM, recognize and prioritize risks, and implement a useful tool in the development of a Risk Management Program addressing HSE issues.

#### **3. Aspects of risk management necessary for a HSE program**

System Safety can be described as a sub-discipline of systems engineering that applies scientific, engineering and management principles to ensure adequate safety, the timely identification of hazard risk, and initiation of actions to prevent or control those hazards throughout the life cycle and within the constraints of operational effectiveness, time, and cost (Vincoli, 2006).

One of the key aspects of safety management is the proper management of risk. There are several ways of defining risk, but all of them share a common core: they define risk as combination of its independent variables likelihood and severity. The new ISO 31.000:2009, entitled "Risk Management", presents a series of guidelines and principles for its management. ISO 31.000:2009 defines risk as:

*"Risk - effect of uncertainty on objectives* 

*NOTE 1 an effect is a deviation from the expected — positive and/or negative.* 

*NOTE 2 Objectives can have different aspects (such as financial, health and safety, and environmental goals) and can apply at different levels (such as strategic, organization-wide, project, product and process).* 

*NOTE 3 Risk is often characterized by reference to potential events and consequences), or a combination of these.* 

*NOTE 4 Risk is often expressed in terms of a combination of the consequences of an event (including changes in circumstances) and the associated likelihood of occurrence.* 

*NOTE 5 Uncertainty is the state, even partial, of deficiency of information related to, understanding or knowledge of an event, its consequence, or likelihood"* 

The concept of risk indicates that it relates to activities or tasks to be performed, being intimately related to a human behavior or environment. As an example, a fuel, such as gasoline, isolated from its context, does not present any level of risk by itself. However, when this fuel is considered to be handled at an environment where sources of ignition are present, for example, dealing with gasoline becomes a hazardous activity. The associated risk will vary according to the behavior of the handler and environmental where it is done. As stated by (Ciocoiu and Dobrea 2010) "even apparently insignificant risks have the potential, as they interact with other events and conditions, to cause great damage. "

Due to the very nature of risk, it is present in almost every activity, job or task performed in the modern world. The accelerating pace of business, globalization, the financial crisis, all contribute to the growing number and complexity of risks and to the greater responsibility for managing risks on an enterprise-wide scale (Ciocoiu and Dobrea, 2010). This leads to the need of managing occupational risks ahead in order to assure minimum casualties and optimum performance. However, the risk is also a very complex entity, which directs to difficulties when understanding and managing.

It is commonly accepted that a proper method for assessing and managing risks pass through decomposing the "risk" in its independent variables: *frequency, severity,* and *scenario*. Therefore, the dependent variable "Risk" can be written as:

#### *Risk = f (frequency, severity, scenario)*

Decomposing the risk in independent variables and further analyzing each variable is the core method presented in the MIL STD 882 for preliminary Hazard analysis. This concept has proved to be successful , since it is still used by many standards, including the forth review of MIL STD 882 (United States, 2003), OHSAS 18.001:2007 (OHSAS, 2007) and ISO 31.000:2009 (ISO, 2009)

#### **3.1 The risk management process**

30 Risk Management for the Future – Theory and Cases

and by an expanded or more comprehensive perspective, to all surrounding environments. HSE is becoming increasingly important, as well as demanded, in any company's effort towards sustainability and legal adequacy. It is becoming part of its regular operations and

In order to organize a HSE Program one needs to develop and structure (ISO 14.001:2007, 2007) a set of activities in a close relation with a Risk Management Program (ISO 31.000:2009, 2009). Determination of scope and objectives are necessary for the establishment of such a Risk Management Program. In this phase, each step of this management process must be defined, as well as its expected results. After that, the mapping of all organization's processes and also their interactions must be performed (the ones that interfere in risk management). On this phase of the HSE effort, all activities, operations and the relations between them must be clearly identified, as they represent potential sources of hazard. Moreover, in order to achieve enough knowledge to underlie adequate action of HSE process, data must be collected from the activities and operations, about its **Processes** (inputs and outputs), its **People** who work

After data collection and the processes mapping are done, the management process is able to perform a **Hazard Mapping and Identification**, which consists in identification, localization and classification of the hazards involved in each process activities of the organization. This classification is performed according to two aspects: type of hazard existent, such as physical, chemical, biological etc., and the severity of its impact. The second one is traduced mathematically by weights that can be represented in a boarding selection. After these entire actions have been performed one can establish the necessary set of information in order to develop the HM (Haddad *et al*, 2008) application in the next stage. With the sequential implementation of the concepts and tools listed one should be able to apply these concepts, use the HM, recognize and prioritize risks, and implement a useful tool in the development of a Risk Management Program addressing HSE issues.

System Safety can be described as a sub-discipline of systems engineering that applies scientific, engineering and management principles to ensure adequate safety, the timely identification of hazard risk, and initiation of actions to prevent or control those hazards throughout the life cycle and within the constraints of operational effectiveness, time, and

One of the key aspects of safety management is the proper management of risk. There are several ways of defining risk, but all of them share a common core: they define risk as combination of its independent variables likelihood and severity. The new ISO 31.000:2009, entitled "Risk Management", presents a series of guidelines and principles for its

*NOTE 2 Objectives can have different aspects (such as financial, health and safety, and environmental goals) and can apply at different levels (such as strategic, organization-wide, project,* 

**3. Aspects of risk management necessary for a HSE program** 

*NOTE 1 an effect is a deviation from the expected — positive and/or negative.* 

is commonly required by regulatory bodies, clients and society.

there, and generally about the **Organization** itself.

cost (Vincoli, 2006).

*product and process).* 

management. ISO 31.000:2009 defines risk as:

*"Risk - effect of uncertainty on objectives* 

Before human's development of *risk management* process and the clear concept of *system safety*, the common technique used to deal with risk was mainly based on a *trial and error* approach. This culture led mankind to fix problems only after its consequences were observed at the already designed running system. In opposition, the idea of minimizing risks until acceptable levels by trying to predict the occurrence of accidents and taking measures in order to avoid them is widely diffused nowadays. This approach characterizes the concept of risk management.

Risk management can be defined as the collection of culture, processes and structures that are directed towards realizing potential opportunities whilst managing adverse effects (Australia, 2004). In this context, it is a complex process and can be understood as a systematic application of management policies, procedures and practices.

Hazard Matrix Application in Health, Safety and Environmental Management Risk Evaluation 33

Within the risk management, which is an interactive process where the risk is studied again after all the mitigations are in place (as indicated by the arrow linking "treat risk" and "monitoring and review" in figure 01), one major phase in the overall process is assess the risk. The Australian and New Zealand Standards AS NZS 4360:2004 defines that this phase comprehends: Identify the risk, analyze the risk and evaluate the risk, and defines its steps

Risk analysis: systematic process to understand the nature of the risk and deduce its

Risk identification: the process of determining what, where, when, why and how

Risk evaluation: the process of comparing the level of risk. In many cases the risk

Furthermore, due to resources limitation, which is unavoidable, addressing all indentified risks becomes a non-realistic approach. As resources can be limited financially, technically, or even related to time or personnel, one will need to implement a system to highlight the most critical hazards and sectors, so that appropriate resources application can be assured. The important role of a prioritization system highlighted above is efficiently accomplished by HM, since its main objective is to establish a priority ranking

Companies have one primary goal: profit. This is the reason for their existence and thus almost all decisions taken at business environment unavoidably aim at profits increase (Mello, 2004). In this context, hazard minimization and mainly the prevention and

As it is clear that any company works with limited resources, there ought to be a prioritization tool able to identify such as which risks or company's sectors are more critical, on which the plan of risks mitigation can be based and oriented. Therefore, the best

In this context, must be emphasized that there are many aspects in which prioritization can be established. It can be financial aspect, so that more money is spent on the priority issue and it is assigned a larger proportion of the available budget. Alternatively, 'priority' may be temporally defined, as all risk issues cannot be tackled simultaneously. An identified priority issue would thus be address in precedence to another, which may be deferred until a later time. Temporal prioritization is fundamental to the development of long-term strategic risk management plans. (Centre for Environmental & Risk

Situated right between the Evaluation and the Treatment phases at Risk Management Process, described by Figure 1, risks prioritization becomes a strategic part of this process when it is taken for its real application, since, after risk analysis and evaluation, it is possible that resources limitations naturally lead to a necessary chose of more critical measures to be

mitigation of its consequences must be established in a systemic and optimized way.

utilization of financial, labor or time resources can be assured.

taken at a first moment, as well as demand a temporal ordination.

evaluation involves establish a priority among several risks.

as follow:

level;

something could happen:

among risks and sectors.

Management, 1997)

**3.1.1 The importance of prioritization** 

The NZS 4360:2004 guideline (AUSTRALIA, 2004) determines that a proper overall risk management process incorporates several other tasks, such as:


The ISO 31.000:2009, in its turn, defines risk management as:

*"Risk management:* 

*process of systematic application of management policies, procedures and practices to the activities of communicating, consulting, establishing the context, and identifying, analyzing, evaluating, treating, monitoring and reviewing risk"* 

Fig. presents an overview of the entire risk management process, based upon the process described in the NZS 4360:2004 guideline (Australia, 2004), using a block diagram representation.

Fig. 1. Risk Management overview (based on ISO 31000: 2009)

At this point, it is important to highlight that the success of risk treatment depends directly on how complete its preliminary analysis, which identifies, describes and classifies them. Risk identification of any organization requires the previous knowledge of its activities and processes, of the external market conjuncture and the legal, social, political and cultural environment in which the company is inserted, and for that, it must be clearly defined its strategic objectives (Muniz, 2011).

Within the risk management, which is an interactive process where the risk is studied again after all the mitigations are in place (as indicated by the arrow linking "treat risk" and "monitoring and review" in figure 01), one major phase in the overall process is assess the risk. The Australian and New Zealand Standards AS NZS 4360:2004 defines that this phase comprehends: Identify the risk, analyze the risk and evaluate the risk, and defines its steps as follow:


Furthermore, due to resources limitation, which is unavoidable, addressing all indentified risks becomes a non-realistic approach. As resources can be limited financially, technically, or even related to time or personnel, one will need to implement a system to highlight the most critical hazards and sectors, so that appropriate resources application can be assured. The important role of a prioritization system highlighted above is efficiently accomplished by HM, since its main objective is to establish a priority ranking among risks and sectors.

#### **3.1.1 The importance of prioritization**

32 Risk Management for the Future – Theory and Cases

The NZS 4360:2004 guideline (AUSTRALIA, 2004) determines that a proper overall risk

*process of systematic application of management policies, procedures and practices to the activities of communicating, consulting, establishing the context, and identifying, analyzing, evaluating,* 

Fig. presents an overview of the entire risk management process, based upon the process described in the NZS 4360:2004 guideline (Australia, 2004), using a block diagram

At this point, it is important to highlight that the success of risk treatment depends directly on how complete its preliminary analysis, which identifies, describes and classifies them. Risk identification of any organization requires the previous knowledge of its activities and processes, of the external market conjuncture and the legal, social, political and cultural environment in which the company is inserted, and for that, it must be clearly defined its

management process incorporates several other tasks, such as:

The ISO 31.000:2009, in its turn, defines risk management as:

Fig. 1. Risk Management overview (based on ISO 31000: 2009)

strategic objectives (Muniz, 2011).

 Communication, Identification, Analysis, Evaluation, Treatment, Monitoring; and Reviewing.

*"Risk management:* 

representation.

*treating, monitoring and reviewing risk"* 

Companies have one primary goal: profit. This is the reason for their existence and thus almost all decisions taken at business environment unavoidably aim at profits increase (Mello, 2004). In this context, hazard minimization and mainly the prevention and mitigation of its consequences must be established in a systemic and optimized way.

As it is clear that any company works with limited resources, there ought to be a prioritization tool able to identify such as which risks or company's sectors are more critical, on which the plan of risks mitigation can be based and oriented. Therefore, the best utilization of financial, labor or time resources can be assured.

In this context, must be emphasized that there are many aspects in which prioritization can be established. It can be financial aspect, so that more money is spent on the priority issue and it is assigned a larger proportion of the available budget. Alternatively, 'priority' may be temporally defined, as all risk issues cannot be tackled simultaneously. An identified priority issue would thus be address in precedence to another, which may be deferred until a later time. Temporal prioritization is fundamental to the development of long-term strategic risk management plans. (Centre for Environmental & Risk Management, 1997)

Situated right between the Evaluation and the Treatment phases at Risk Management Process, described by Figure 1, risks prioritization becomes a strategic part of this process when it is taken for its real application, since, after risk analysis and evaluation, it is possible that resources limitations naturally lead to a necessary chose of more critical measures to be taken at a first moment, as well as demand a temporal ordination.

Hazard Matrix Application in Health, Safety and Environmental Management Risk Evaluation 35

The majority of the risk schemes available approach the problem using the principle of compartmentalization, studying sub-systems and sub-components, on behalf of simplicity

This "compartmentalization" is done setting borders in the scenario. These borders can set sub-areas for analysis, sub–system, and sub-component or split the "target" of the analysis using nodes. The main representative tool of this technique that places nods in the flow of matter and energy flows and analyze the risks in each nod is the HazOp. **(**Committee For

Irrespective of the chosen method to assess risk, a quantitative analysis is to be preferred over any qualitative, mainly because a quantitative approach establishes a hierarchy between risks. The HM is an example of a risk assessment method designed to prioritize

In summary, the risk assessment schemes should be selected matching the strengths and

 **HazOP** - This scheme suite perfectly a scenario where the productive process can be represented (drawn) as a flow chart, due to the easiness of cutting the flow applying nods on it. It is known that a block diagram can be used to represent a "flow chart" and, therefore, allow application of HazOP to a discontinuous process (such as an assembling line), if the level of risk justifies this approach. **(**Committee For The

 **FMEA** - The FMEA is the risk assessment scheme published by the MIL STD 1629 (UNITED STATES, 2000) and used spreadsheets to decompose the risk in its failure modes, causes and consequences. This FMEA suites best when applied to machinery or

 **Tree Analysis** - All the assessment methods that fold into this category assess the risk by set a chain of events (causes and consequences). These methods regard to determine

 **Matrix Schemes** - These schemes provide a very flexible approach to the risk and hazards analyses. As a general rule, these tools compensate the lack of deep by decomposing the risk in its independent variables (likelihood and severity) and analyzing each variable separately. These methods are also indicated to assess risk of a particular task in hand. **The hazard matrix proposed in this chapter is one example of** 

This section provided an overview about risk management in a general approach. However, risk management procedures may differ depending upon scenario and applications. The next section addresses the risk management and evaluation when applied specifically to

When it comes to environmental risk, the scenario is a key part of the entire risk assessment routine. In general, the hazards identification process is the same for both environmental and occupational risk management. The main difference between them will be related to the

weakness of each scheme with a given scenario and the output requirements:

the frequency (number) for the likelihood of the risk to occur.

**3.3 Environmental risk management and evaluation** 

scope utilized to determine the scenario.

in more complex systems.

The Prevention of Disasters, 1997**)**,

risks, hazards and environmental (sectors).

Prevention of Disasters, 1997**)**,

equipment's.

**this category.** 

environmental risks.

Further, studying risk management, one can conclude that risk prioritization is a key aspect of the overall procedure. As risk prioritization and treatment are intrinsically connected to risk analysis and evaluation, the next section briefly presents and discusses methods commonly used to evaluate risks.

#### **3.2 Risk evaluation schemes**

In the risk management process one important aspect is the risk analysis, which is done using a chosen methodology, which is sometimes called "risk assessment scheme".

Despite the fact that Hammer's book (reference) is an old reference, it still is quoted and cited in many recent works and manuals of risk assessment, due to its clear ideas and concepts. Although the risk assessment schemes presented by Hammer might be somehow obsolete, the concepts are not.

There are an unlimited number of schemes. Each one has its strengths and weakness. Hammer, in his book, presents several possible schemes, which can be folded into 4 greater categories:


It is important to remark that every risk assessment method will fall into two of the four categories. A risk assessment tool will be qualitative or quantitative and formatted as tree or spread sheet. This leads to a classification matrix as shown in Table 1.


Table 1. Risk Assessment – Classification Table

The schemes of risk analysis under the **tree concept** focus on establishing a chain of events, as well as assess the risk occurrence likelihood. The TNO Red Book **(**Committee For The Prevention of Disasters, 1997**)** presents some fault tree analysis methods. Risk assessment performed using fault trees technique can provide a result as simple as a series of causes and effects (**qualitative approach**) or as complex as the evaluation of risk occurrence probability (**quantitative approach**). It is also important to remark that the analysis complexity varies at the same rate as the analyzed system complexity.

The other category of risk assessment is the spreadsheet. Some of the most used risk assessment schemes fall into the spreadsheet category. This category counts widely used methods like HazOp **(**Committee For The Prevention of Disasters, 1997**)**, FMEA **(**United States. MIL-STD-1629, 2000**),** Hazard Preliminary Analysis (HPA) (United States, MIL-STD 882-D, 2003) and the HAZARD MATRIX (Haddad, 2008).

Further, studying risk management, one can conclude that risk prioritization is a key aspect of the overall procedure. As risk prioritization and treatment are intrinsically connected to risk analysis and evaluation, the next section briefly presents and discusses methods

In the risk management process one important aspect is the risk analysis, which is done

Despite the fact that Hammer's book (reference) is an old reference, it still is quoted and cited in many recent works and manuals of risk assessment, due to its clear ideas and concepts. Although the risk assessment schemes presented by Hammer might be somehow

There are an unlimited number of schemes. Each one has its strengths and weakness. Hammer, in his book, presents several possible schemes, which can be folded into 4 greater

It is important to remark that every risk assessment method will fall into two of the four categories. A risk assessment tool will be qualitative or quantitative and formatted as tree or

The schemes of risk analysis under the **tree concept** focus on establishing a chain of events, as well as assess the risk occurrence likelihood. The TNO Red Book **(**Committee For The Prevention of Disasters, 1997**)** presents some fault tree analysis methods. Risk assessment performed using fault trees technique can provide a result as simple as a series of causes and effects (**qualitative approach**) or as complex as the evaluation of risk occurrence probability (**quantitative approach**). It is also important to remark that the analysis complexity varies at

The other category of risk assessment is the spreadsheet. Some of the most used risk assessment schemes fall into the spreadsheet category. This category counts widely used methods like HazOp **(**Committee For The Prevention of Disasters, 1997**)**, FMEA **(**United States. MIL-STD-1629, 2000**),** Hazard Preliminary Analysis (HPA) (United States, MIL-STD

Analysis formatted as tree Analysis formatted as Spread

Sheet

spread sheet. This leads to a classification matrix as shown in Table 1.

using a chosen methodology, which is sometimes called "risk assessment scheme".

commonly used to evaluate risks.

**3.2 Risk evaluation schemes** 

obsolete, the concepts are not.

 Analysis in spreadsheets Qualitative Analysis Quantitative Analysis

categories:

Analysis in trees

Qualitative Results Quantitative Results

Table 1. Risk Assessment – Classification Table

the same rate as the analyzed system complexity.

882-D, 2003) and the HAZARD MATRIX (Haddad, 2008).

The majority of the risk schemes available approach the problem using the principle of compartmentalization, studying sub-systems and sub-components, on behalf of simplicity in more complex systems.

This "compartmentalization" is done setting borders in the scenario. These borders can set sub-areas for analysis, sub–system, and sub-component or split the "target" of the analysis using nodes. The main representative tool of this technique that places nods in the flow of matter and energy flows and analyze the risks in each nod is the HazOp. **(**Committee For The Prevention of Disasters, 1997**)**,

Irrespective of the chosen method to assess risk, a quantitative analysis is to be preferred over any qualitative, mainly because a quantitative approach establishes a hierarchy between risks. The HM is an example of a risk assessment method designed to prioritize risks, hazards and environmental (sectors).

In summary, the risk assessment schemes should be selected matching the strengths and weakness of each scheme with a given scenario and the output requirements:


This section provided an overview about risk management in a general approach. However, risk management procedures may differ depending upon scenario and applications. The next section addresses the risk management and evaluation when applied specifically to environmental risks.

#### **3.3 Environmental risk management and evaluation**

When it comes to environmental risk, the scenario is a key part of the entire risk assessment routine. In general, the hazards identification process is the same for both environmental and occupational risk management. The main difference between them will be related to the scope utilized to determine the scenario.

Hazard Matrix Application in Health, Safety and Environmental Management Risk Evaluation 37

STD 882). Each sector constitutes a line (from 1 to y) in the hazard matrix, followed by a column that stands for the number of workers on that sector. As for the other columns, they

After building the matrix, the hazards identified are preliminarily assessed though out the use of a "Risk Assessment Code" (RAC). This RAC follows a simple criterion, which varies according to the scenario, availability of data or even precision required. The important is that the criteria must be the same for the entire matrix, as well as be able to provide a

When it comes to occupational hazards, one valid criterion is presented (as example) in Table 2.

**<sup>1</sup>**The exposure of this hazard occurs bellow the action level AND

**<sup>3</sup>**The exposure of this hazard occurs bellow the action level AND,

**<sup>6</sup>**The exposure level is between the action level and the Threshold Value Limit (TVL-TWA) or equivalent. **<sup>9</sup>**The exposure level is above Threshold Value Limit (TVL-TWA)

Table 2. Risk Assessment Codes for Hazardous agents (chemicals, physical or Biological

best represents the exposure to the Hazard "j" faced by the workers in sector "i".

the columns that draws the borders of the RAC. Table 3 presents a general HM.

Therefore, the HM is completed by evaluating the hazards using the RAC pre-selected for a given scenario. Each given position within the matrix corresponds to the hazard in a given sector. That means that the value written in the position (*i,j*) stands for the RAC () which

In the HM, the Sectors (S) and Number of Workers (W) forms the lines and the hazards (H)

**S1 W1** R1,1 R1,2 R1,3 … R1,X **S2 W2** R2,1 R2,2 R2,3 … R2,X **S3 W3** R3,1 R3,2 R3,3 … R3,X **… …** … … … … **SY WY** RY,1 RY,2 RY,3 … RY,X

**working H1 H2 H3 … Hx** 

take all the hazards identified in all the sectors, drawing column from 1 to x.

**0** This hazard is NOT present in the sector evaluated

it is occasional

continuously

or equivalent.

numerical number.

**Risk Assessment** 

agents).

**Description / Name** 

**Code Description** 

Note: Action level is half the TVL-TWA value

**Sector Hazards identified**

**Number of people** 

Table 3. Hazard Matrix – General Construction model

At his point, considering this risk scenario context, it is important to clearly define a limit that, in a simplified way, represents the interface between the industry internal and external environment. This limit is well represented by a key concept: the *industry walls*, which defines a separation between occupational and environmental hazards.

During an occupational risk management process, one is concerned with the effects of the hazard within the boundaries of the enterprise, company, unit or industry. This scope guides all decisions, from which methodology use to what consequences should be neglected.

On the opposite, the scope applied over the scenario when an environmental risk management process is undertaken focus on risks source effects on the external area, which means beyond the *industry walls*. Figure 2 represents the difference between environmental and occupational risk management approaches.

Fig. 2. Environmental Risk versus Occupational Risk

#### **4. The Hazard matrix (HM) concept, structure and applications**

The HM methodology, based on the work done by (Haddad *el al* 2008), is a valuable tool to allow determination of prioritization among several risks, hazards and sectors within a given system or environment. This complex system can be anything that held more than a single hazard to be prevented or mitigated, from an industry to an office building.

The HM approach is based on the already cited concept of risk as a function of its severity and probability of occurrence. In a simplified view, as seen before, risk can be defined by the product of its two variables. In the HM, the probabilistic factor is represented by the number of workers exposed to the hazard. The severity factor, in turn, is mathematically traduced by a numerical classification of hazards, which will be more specified later.

The analysis starts by dividing the company in sectors, identifying the hazards and sectors its respective sectors of exposure. Due to that, it is likely to use the hazard matrix combined with other risk identification and assessment tools, like FMEA (MIL STD 1629) or HPA (MIL STD 882). Each sector constitutes a line (from 1 to y) in the hazard matrix, followed by a column that stands for the number of workers on that sector. As for the other columns, they take all the hazards identified in all the sectors, drawing column from 1 to x.

After building the matrix, the hazards identified are preliminarily assessed though out the use of a "Risk Assessment Code" (RAC). This RAC follows a simple criterion, which varies according to the scenario, availability of data or even precision required. The important is that the criteria must be the same for the entire matrix, as well as be able to provide a numerical number.


When it comes to occupational hazards, one valid criterion is presented (as example) in Table 2.

Note: Action level is half the TVL-TWA value

36 Risk Management for the Future – Theory and Cases

At his point, considering this risk scenario context, it is important to clearly define a limit that, in a simplified way, represents the interface between the industry internal and external environment. This limit is well represented by a key concept: the *industry walls*, which

During an occupational risk management process, one is concerned with the effects of the hazard within the boundaries of the enterprise, company, unit or industry. This scope guides all decisions, from which methodology use to what consequences should be

On the opposite, the scope applied over the scenario when an environmental risk management process is undertaken focus on risks source effects on the external area, which means beyond the *industry walls*. Figure 2 represents the difference between environmental

defines a separation between occupational and environmental hazards.

and occupational risk management approaches.

Fig. 2. Environmental Risk versus Occupational Risk

**4. The Hazard matrix (HM) concept, structure and applications** 

a numerical classification of hazards, which will be more specified later.

single hazard to be prevented or mitigated, from an industry to an office building.

The HM methodology, based on the work done by (Haddad *el al* 2008), is a valuable tool to allow determination of prioritization among several risks, hazards and sectors within a given system or environment. This complex system can be anything that held more than a

The HM approach is based on the already cited concept of risk as a function of its severity and probability of occurrence. In a simplified view, as seen before, risk can be defined by the product of its two variables. In the HM, the probabilistic factor is represented by the number of workers exposed to the hazard. The severity factor, in turn, is mathematically traduced by

The analysis starts by dividing the company in sectors, identifying the hazards and sectors its respective sectors of exposure. Due to that, it is likely to use the hazard matrix combined with other risk identification and assessment tools, like FMEA (MIL STD 1629) or HPA (MIL

neglected.

Table 2. Risk Assessment Codes for Hazardous agents (chemicals, physical or Biological agents).

Therefore, the HM is completed by evaluating the hazards using the RAC pre-selected for a given scenario. Each given position within the matrix corresponds to the hazard in a given sector. That means that the value written in the position (*i,j*) stands for the RAC () which best represents the exposure to the Hazard "j" faced by the workers in sector "i".

In the HM, the Sectors (S) and Number of Workers (W) forms the lines and the hazards (H) the columns that draws the borders of the RAC. Table 3 presents a general HM.


Table 3. Hazard Matrix – General Construction model

Hazard Matrix Application in Health, Safety and Environmental Management Risk Evaluation 39

1 1 1,1 1 1,2 1 1, \* \* ... \* *s x f WR WR WR*

2 2 2,1 2 2,2 2 2, 3 3 3,1 3 3,2 3 3,

Analyzing the method to determine each **exposure frequency**, it is possible to determine a

1

1 *i y*

1

Similarly to the global hazard frequency, the global exposure frequency will also be used to

The next stage of the hazard matrix method is determining the **relevancy percentage** , which

*Wi* \* *Ri*, *<sup>j</sup>*

*x* 

*i*1

*fHj*

,

\*

*W R*

*i ij*

*si i*

*f*

\*100,

*i*1

1 *j x*,

*x*

1

% \* 100 \* 100

*j si si <sup>y</sup> <sup>s</sup>*

*f F*

1

*y* 

*y S si i F f* 

*x si i i j j f WR* 

*f WR WR WR f WR WR WR f WR WR WR*

 

*s x s x sy yy yy yy x*

\* \* ... \* \* \* ... \* \* \* ... \*

,1 ,2 ,

,

\*

The other exposure frequencies are determined using similar equations:

general rule for their determination:

The global exposure frequency is determined as follows:

calculate the relevancy percentages. This is done next.

can be calculated via the following set of equations:

%*Hj fHj*

*FH*

\*100

**4.3 Relevancy percentage calculation** 

, where

where

The next stage of the HM approach is to calculate the **hazard frequency of recurrence**, the **exposure frequency** and the **relevancy percentage**.

The hazard frequency of recurrence measures how intense is the overall exposure to a given risk, while the exposure frequency evaluates which sector represents a more hazardous environmental to work in. Both frequencies take into account the number of works exposed and the intensity of the hazard.

The relevancy percentages are a mathematical composition of both hazard frequency of recurrence and exposure frequency to allow easier understanding and prioritization. Next, we present the hazard frequency calculation in more details.

#### **4.1 Hazard frequency calculation**

Taking the first Hazard (H1) in the matrix (Table ), its hazard frequency of recurrence is determined by the following calculation:

$$f\_{H1} = \mathcal{W}\_1 \, \text{\* } R\_{1,1} + \mathcal{W}\_2 \, \text{\* } R\_{2,1} + \mathcal{W}\_3 \, \text{\* } R\_{3,1} + ... + \mathcal{W}\_y \, \text{\* } R\_{y,1}$$

Similar calculations are performed to all the other hazards to determine their hazard recurrence frequency:

$$\begin{aligned} f\_{H2} &= \mathcal{W}\_1 \, \, ^\ast R\_{1,2} + \mathcal{W}\_2 \, ^\ast R\_{2,2} + \mathcal{W}\_3 \, ^\ast R\_{3,2} + \dots + \mathcal{W}\_y \, ^\ast R\_{y,2} \\ f\_{H3} &= \mathcal{W}\_1 \, \, ^\ast R\_{1,3} + \mathcal{W}\_2 \, ^\ast R\_{2,3} + \mathcal{W}\_3 \, ^\ast R\_{3,3} + \dots + \mathcal{W}\_y \, ^\ast R\_{y,3} \\ f\_{Hx} &= \mathcal{W}\_1 \, \, ^\ast R\_{1,x} + \mathcal{W}\_2 \, ^\ast R\_{2,x} + \mathcal{W}\_3 \, ^\ast R\_{3,x} + \dots + \mathcal{W}\_y \, ^\ast R\_{y,x} \end{aligned}$$

This allows the establishment of a general rule for determining the **recurrence frequency** of any hazard within a HM as follows:

$$f\_{H^j\_\mathcal{I}} = \sum\_{i=1}^{\mathcal{V}} \mathcal{W}\_i \, \ast \, \mathcal{R}\_{i,j} \, \prime$$

where

1 *j x*

After all the **hazard recurrence frequencies** are determined, a global hazard frequency can be determined as follows:

$$F\_H = \sum\_{j=1}^{x} f\_{Hj}$$

The global hazard frequency is used to calculate the relevancy percentages. The other key figure of a hazard matrix is the exposure frequency, which is further presented in the next section.

#### **4.2 Exposure frequency calculation**

Following the determination of all the hazard recurrence frequencies, comes the determination of the **exposure frequencies**. Taking the first sector (S1) in the HM (Table ???) the exposure frequency is determined as follows:

$$f\_{s1} = \mathcal{W}\_1 \, \text{\*} \, R\_{1,1} + \mathcal{W}\_1 \, \text{\*} \, R\_{1,2} + ... + \mathcal{W}\_1 \, \text{\*} \, R\_{1,x}.$$

The other exposure frequencies are determined using similar equations:

$$\begin{aligned} f\_{s2} &= \mathcal{W}\_2 \, \, ^\ast R\_{2,1} + \mathcal{W}\_2 \, ^\ast R\_{2,2} + \dots + \mathcal{W}\_2 \, ^\ast R\_{2,\times} \\ f\_{s3} &= \mathcal{W}\_3 \, ^\ast R\_{3,1} + \mathcal{W}\_3 \, ^\ast R\_{3,2} + \dots + \mathcal{W}\_3 \, ^\ast R\_{3,\times} \\ f\_{sy} &= \mathcal{W}\_y \, ^\ast R\_{y,1} + \mathcal{W}\_y \, ^\ast R\_{y,2} + \dots + \mathcal{W}\_y \, ^\ast R\_{y,\times} \end{aligned}$$

Analyzing the method to determine each **exposure frequency**, it is possible to determine a general rule for their determination:

$$f\_{si} = \sum\_{j=1}^{x} \mathcal{W}\_i \, \* \, \mathcal{R}\_{i,j}$$

, where

38 Risk Management for the Future – Theory and Cases

The next stage of the HM approach is to calculate the **hazard frequency of recurrence**, the

The hazard frequency of recurrence measures how intense is the overall exposure to a given risk, while the exposure frequency evaluates which sector represents a more hazardous environmental to work in. Both frequencies take into account the number of works exposed

The relevancy percentages are a mathematical composition of both hazard frequency of recurrence and exposure frequency to allow easier understanding and prioritization. Next,

Taking the first Hazard (H1) in the matrix (Table ), its hazard frequency of recurrence is

1 1 1,1 2 2,1 3 3,1 ,1 *<sup>H</sup>* \* \* \* ... \* *y y f WR WR WR WR*

Similar calculations are performed to all the other hazards to determine their hazard

2 1 1,2 2 2,2 3 3,2 ,2 3 1 1,3 2 2,3 3 3,3 ,3 1 1, 2 2, 3 3, ,

*H y y H y y Hx x x x y y x*

This allows the establishment of a general rule for determining the **recurrence frequency** of

1

1 *j x* After all the **hazard recurrence frequencies** are determined, a global hazard frequency can

> *FH fHj j*1

The global hazard frequency is used to calculate the relevancy percentages. The other key figure of a hazard matrix is the exposure frequency, which is further presented in the next section.

Following the determination of all the hazard recurrence frequencies, comes the determination of the **exposure frequencies**. Taking the first sector (S1) in the HM (Table ???)

*x* 

*y Hj i i j i f WR* 

,

\*

,

*f WR WR WR WR f WR WR WR WR f WR WR WR WR*

 

\* \* \* ... \* \* \* \* ... \* \* \* \* ... \*

**exposure frequency** and the **relevancy percentage**.

we present the hazard frequency calculation in more details.

and the intensity of the hazard.

**4.1 Hazard frequency calculation** 

any hazard within a HM as follows:

be determined as follows:

**4.2 Exposure frequency calculation** 

the exposure frequency is determined as follows:

recurrence frequency:

where

determined by the following calculation:

$$1 \le i \le \nu$$

The global exposure frequency is determined as follows:

$$F\_S = \sum\_{i=1}^{y} f\_{si}$$

Similarly to the global hazard frequency, the global exposure frequency will also be used to calculate the relevancy percentages. This is done next.

#### **4.3 Relevancy percentage calculation**

The next stage of the hazard matrix method is determining the **relevancy percentage** , which can be calculated via the following set of equations:

$$\text{°/°}\_{H\text{j}} = \frac{f\_{H\text{j}}}{F\_H} \ast 100 = \frac{\sum\_{i=1}^{\text{y}} W\_i \ast R\_{i,j}}{\sum\_{i=1}^{\text{x}} f\_{H\text{j}}} \ast 100\text{.}$$

where

$$1 \le j \le \mathfrak{x}\_{\prime\prime}$$

$$\%\_{si} = \frac{f\_{si}}{F\_s} \ast 100 = \frac{\sum\_{j=1}^{x} \mathcal{W}\_i \ast R\_{i,j}}{\sum\_{i=1}^{y} f\_{si}} \ast 1000$$

Hazard Matrix Application in Health, Safety and Environmental Management Risk Evaluation 41

**H1 H2 H3 … Hx** 

**A1 P1** R1,1 R1,2 R1,3 … R1,X **fs1 %s1 A2 P2** R2,1 R2,2 R2,3 … R2,X **fS,2 %S,2 A3 P3** R3,1 R3,2 R3,3 … R3,X **fS3 %S3 … …** … … … … **… … AY PY** RY,1 RY,2 RY,3 … RY,X **fSY %SY** 

Thirdly, the risk levels need to be re-designed to match environmental events. Due to the complexity of assess effects and predict damages, it is recommended to keep the description

of environmental risks as simple as possible. Table 6 presents one suitable example.

**0** This hazard is NOT percept in that given vulnerable area

**<sup>3</sup>**This Hazards can severely damage the environmental and harm

**<sup>9</sup>**This hazard can cause immediate death of at least one person

Table 6. Environmental Risk Assessment Codes, based upon MIL STD 882 Severity

The mathematical determination of the hazard frequency, exposure frequency, relevancy

This section presented an application of the Hazard Matrix tool to Environmental Risk Analysis. However, HM is a valuable tool for other scenarios as well. One example of such application of HM is in project management, which is further explored in the next section.

One of the most useful and enriching results of a Risk Prioritization tool, which specially includes the HM, is the global and comparative view of the organization's sectors (as well as their interactions) that it provides. Nevertheless, some productive sectors, such as the Construction Industry, have its operation based on projects, where the final product is the main goal of the production activities, which are finished when the product is completed.

people, and without victims.

people, without loss of lives

within the vulnerable area

percentages remains the same as presented in the section 3.

**5.2 Projects/temporal applications** 

**fH1 fH2 fH3 fHx** 

This Hazard can damage the environment in a reparable way, without any permanent damage to structures, environmental or

**%H1 %H2 %H3 %Hx 100%** 

Vulnerable area

**Description / Name** 

> **Risk Assessment Code**

**1** 

categories.

Hazards identified

**Number of people Living / working** 

Table 5. Environmental Hazard Matrix

**Description** 

where

1 *i y*

With these calculations performed, we are ready to assemble the entire HM. This is discussed next.

#### **4.4 The complete hazard matrix**

Once all the calculations are concluded, the HM from Table 3 can be updated to incorporate these percentages. Table 4 Hazard Matrix – Relevancy Percentages presents this newer and complete matrix.

#### **5. Hazard matrix applications in HSE**

Like risk management, hazard matrix application also varies depending upon scenario and scope of analyses. This section addresses these differences and customization required when one applies HM to HSE as well as other applications.


Table 4. Hazard Matrix – Relevancy Percentages

#### **5.1 Environmental risks prioritization**

The main difference between applying the HM to prioritize occupational hazards and environmental hazards is the understanding of the scenario. As already discussed in figure 2, one addressing the occupational hazards will analyze risk, frequencies and exposure within the boundaries of an enterprise, Industry or site, while the environmental risk assessment will regard the effects on the exterior of this same enterprise.

Hence, in cases on which the HM is intended to be applied to prioritize and assess environmental risks, some small adaptations are due.

Firstly, the sectors of an enterprise will be replaced to vulnerable areas already identified on the neighborhood (or areas of influence) of a given enterprise, industry or unit. Subsequently, the number of workers will be replaced by an average number of people living / working in that given vulnerable areas. Secondly, the hazards identified will concern to risks that can create effects outside the enterprise, industry or unit boundaries. From these adaptations, the environmental HM is adapted as shown in table 5.


Table 5. Environmental Hazard Matrix

40 Risk Management for the Future – Theory and Cases

1 *i y*

With these calculations performed, we are ready to assemble the entire HM. This is

Once all the calculations are concluded, the HM from Table 3 can be updated to incorporate these percentages. Table 4 Hazard Matrix – Relevancy Percentages presents this newer and

Like risk management, hazard matrix application also varies depending upon scenario and scope of analyses. This section addresses these differences and customization required when

**H1 H2 H3 … Hx S1 W1** R1,1 R1,2 R1,3 … R1,X **fs1 %s1 S2 W2** R2,1 R2,2 R2,3 … R2,X **fS,2 %S,2 S3 W3** R3,1 R3,2 R3,3 … R3,X **fS3 %S3 … …** … … … … **… … SY WY** RY,1 RY,2 RY,3 … RY,X **fSY %SY** 

The main difference between applying the HM to prioritize occupational hazards and environmental hazards is the understanding of the scenario. As already discussed in figure 2, one addressing the occupational hazards will analyze risk, frequencies and exposure within the boundaries of an enterprise, Industry or site, while the environmental risk assessment will regard the effects on the exterior of this same

Hence, in cases on which the HM is intended to be applied to prioritize and assess

Firstly, the sectors of an enterprise will be replaced to vulnerable areas already identified on the neighborhood (or areas of influence) of a given enterprise, industry or unit. Subsequently, the number of workers will be replaced by an average number of people living / working in that given vulnerable areas. Secondly, the hazards identified will concern to risks that can create effects outside the enterprise, industry or unit boundaries.

From these adaptations, the environmental HM is adapted as shown in table 5.

**fH1 fH2 fH3 fHx** 

**%H1 %H2 %H3 %Hx 100%** 

where

discussed next.

complete matrix.

**Sector Hazards** 

**Description / Name** 

enterprise.

**4.4 The complete hazard matrix** 

**5. Hazard matrix applications in HSE** 

**identified** 

**Number of people working** 

one applies HM to HSE as well as other applications.

Table 4. Hazard Matrix – Relevancy Percentages

environmental risks, some small adaptations are due.

**5.1 Environmental risks prioritization** 

Thirdly, the risk levels need to be re-designed to match environmental events. Due to the complexity of assess effects and predict damages, it is recommended to keep the description of environmental risks as simple as possible. Table 6 presents one suitable example.


Table 6. Environmental Risk Assessment Codes, based upon MIL STD 882 Severity categories.

The mathematical determination of the hazard frequency, exposure frequency, relevancy percentages remains the same as presented in the section 3.

This section presented an application of the Hazard Matrix tool to Environmental Risk Analysis. However, HM is a valuable tool for other scenarios as well. One example of such application of HM is in project management, which is further explored in the next section.

#### **5.2 Projects/temporal applications**

One of the most useful and enriching results of a Risk Prioritization tool, which specially includes the HM, is the global and comparative view of the organization's sectors (as well as their interactions) that it provides. Nevertheless, some productive sectors, such as the Construction Industry, have its operation based on projects, where the final product is the main goal of the production activities, which are finished when the product is completed.

Hazard Matrix Application in Health, Safety and Environmental Management Risk Evaluation 43

Taking the work done by (Galante 2008), in which a hazard matrix methodology was applied to this very kind of manufactory, a hazard matrix for a lead azide unit can be

**workshop 2** 9 1 0 1 **22 23%** 

**workshop 2** 0 1 0 1 **4 4%** 

**workshop 2** 0 1 0 1 **4 4%** 

**workshop 4** 6 1 3 1 **44 46% Drying 2** 3 1 6 1 **22 23%** 

Analyzing the results achieved by calculating the hazard matrix, it is possible to prioritize

From the analysis, it is possible to conclude that the most relevant hazard is related to deal with lead salts. This relates to the toxicity of lead and its effects once within the human body. Since the exposure to lead involves more people, it got a higher relevance percentage, which differs from the "initial guess" that "explosion" would be the most relevant hazard. As for the sector, the precipitation workshop got the higher relevance, mainly due to the

In summary, according to the HM written for this scenario, the top priority when comes to mitigate and control hazards would be address the lead exposure (50% of all the hazards relevancies are due to lead exposure) in general, and in particular its exposure within the

precipitation workshop (this area counts for 46% of the exposure relevancies).

**Physical Hazard - Noise** 

**Fh 48 12 24 12** 

**Accident - Explosion** 

**%H 50% 12.5% 25% 12.5% 100%** 

**Accident – Electrical Discharge**

**Fs %s** 

**Exposure to Chemicals (Lead salts)** 

written as in table 8.

**Pb(NO3)2 preparation** 

**Na(OH) preparation** 

**Na(N3) preparation** 

**Precipitation reaction** 

Drying – 23%

**Sectors:** 

**Hazards:** 

**SECTOR HAZARDS** 

**Description Number of** 

**Workers** 

Table 8. Hazard Matrix for Lead Azide manufactory

Precipitation reaction workshop – 46% Pb(NO3)2 preparation workshop – 23%

Na(OH) preparation workshop – 4% Na(N3) preparation workshop – 4%

Accident – Explosion – 25% Physical Hazard – Noise – 12.5% Accident – Electrical Discharge – 12.5%

higher number or workers in the sector.

Exposure to Chemicals (Lead salts) – 50%

the sector and the hazards using the relevance percentage:

Such kind of activities, in terms of risk assessment and prioritization, may demand a specific approach, in order to provide to project's managers its global understanding and the associated risks related to each temporal stage, as well as their interactions along time and its effects on the project.

In this context, in order to meet such demands, a convenient adaptation of HM is suggestively developed. Initially, the **SECTOR** column will be replaced by a **STAGE** column, where will be allocated each stage of the project. Alternatively, it is quite acceptable to create sub-stages, if it seems applicable. The probabilistic factor continues to be well represented by the number of employees who is going to be involved with each stage.

It is important to emphasize that these analysis do not intent to replace the objectives and results of conventional HM, but it only provides, when it is possible and convenient, a different and complementary view of the whole process in a temporal approach. Therefore, the combined use of both types is quite possible.

### **6. Case studies**

In this section, two study cases are presented. Each of the cases of study deals with a different aspect and application of the hazard matrix method.

#### **6.1 Chemical process unit**

Urbanski (1964) and (Meyer 1977) present a method to produce lead azide via precipitation using lead nitrate and sodium azide as reactants. This method is largely used in the explosive industry, been lead azide is a chemical compound with explosives properties and largely used as a primer explosive (payload of blasting caps) in mining activities. Due to its (lead azide) explosive properties, "explosion" is expected to be the most relevant hazard. However, the hazard matrix method proves that "perception" alone is not a suitable risk assessment technique.

Since lead azide manufacture involves chemical compounds, the RAC (Risk assessment codes) should take into account the threshold exposure limits as a parameter. Table 7 presents the RAC used in this case of study.


Table 7. RAC for a chemical process unit

Taking the work done by (Galante 2008), in which a hazard matrix methodology was applied to this very kind of manufactory, a hazard matrix for a lead azide unit can be written as in table 8.


Table 8. Hazard Matrix for Lead Azide manufactory

Analyzing the results achieved by calculating the hazard matrix, it is possible to prioritize the sector and the hazards using the relevance percentage:

#### **Sectors:**

42 Risk Management for the Future – Theory and Cases

Such kind of activities, in terms of risk assessment and prioritization, may demand a specific approach, in order to provide to project's managers its global understanding and the associated risks related to each temporal stage, as well as their interactions along time and

In this context, in order to meet such demands, a convenient adaptation of HM is suggestively developed. Initially, the **SECTOR** column will be replaced by a **STAGE** column, where will be allocated each stage of the project. Alternatively, it is quite acceptable to create sub-stages, if it seems applicable. The probabilistic factor continues to be well represented by the number of employees who is going to be involved with each

It is important to emphasize that these analysis do not intent to replace the objectives and results of conventional HM, but it only provides, when it is possible and convenient, a different and complementary view of the whole process in a temporal approach. Therefore,

In this section, two study cases are presented. Each of the cases of study deals with a

Urbanski (1964) and (Meyer 1977) present a method to produce lead azide via precipitation using lead nitrate and sodium azide as reactants. This method is largely used in the explosive industry, been lead azide is a chemical compound with explosives properties and largely used as a primer explosive (payload of blasting caps) in mining activities. Due to its (lead azide) explosive properties, "explosion" is expected to be the most relevant hazard. However, the hazard matrix method proves that "perception" alone is not a suitable risk

Since lead azide manufacture involves chemical compounds, the RAC (Risk assessment codes) should take into account the threshold exposure limits as a parameter. Table 7

Risk Assessment Codes

its effects on the project.

the combined use of both types is quite possible.

presents the RAC used in this case of study.

Table 7. RAC for a chemical process unit

different aspect and application of the hazard matrix method.

9

6

 3 1 0

stage.

**6. Case studies** 

**6.1 Chemical process unit** 

assessment technique.

TVL-TWA

Action Level

Precipitation reaction workshop – 46% Pb(NO3)2 preparation workshop – 23% Drying – 23% Na(OH) preparation workshop – 4% Na(N3) preparation workshop – 4%

#### **Hazards:**

Exposure to Chemicals (Lead salts) – 50% Accident – Explosion – 25% Physical Hazard – Noise – 12.5% Accident – Electrical Discharge – 12.5%

From the analysis, it is possible to conclude that the most relevant hazard is related to deal with lead salts. This relates to the toxicity of lead and its effects once within the human body. Since the exposure to lead involves more people, it got a higher relevance percentage, which differs from the "initial guess" that "explosion" would be the most relevant hazard.

As for the sector, the precipitation workshop got the higher relevance, mainly due to the higher number or workers in the sector.

In summary, according to the HM written for this scenario, the top priority when comes to mitigate and control hazards would be address the lead exposure (50% of all the hazards relevancies are due to lead exposure) in general, and in particular its exposure within the precipitation workshop (this area counts for 46% of the exposure relevancies).

Hazard Matrix Application in Health, Safety and Environmental Management Risk Evaluation 45

Source: Translated from (Muniz 2011) Table 10. Hazard Matrix – GENERAL

#### **6.2 Oil Extraction – Offshore platform**

Nowadays modern society and economy is heavily dependent upon oil and its derivatives. From that, it is just logical to assume that oil industry is a major player within the international economy, being present worldwide, from prospection, extraction and processing. At the same time, oils are fuels and by that reason they represent a hazard to be managed. Even more, the large amounts of oil dealt with worldwide exponentially increases the hazard, both occupational (intense labor, heavy machinery, pumps, chemical hazards, fire hazard, and accidents in general.) and environmental (major fires, explosions, major leaks both in land and water).

In a greater scope, there are the oil extraction operations off shore. Extraction platforms stationed off shore are one important representative of this group. These platforms are very complex installations, being capable to drill and build the oil wells, extract, produce and hold both oil and high pressure gases, as well as perform the entire set of required maintenances (Freitas *et al* 2001; Booth and Butler,1992).

Due to the off shore environment in which oil platform operate and the hazards of its operations and products dealt with, as well as economical relevance in modern society, they constitute an extremely important scenario for risk assessment, including hazard matrix ranking system. Muniz (2011) developed his work having an off-shore oil extraction platform as a case of study. The chosen platform is set at the Brazilian coast, near the city of Vitoria.


The work performed by (Muniz 2011), the RAC used were as in table 9

Source: Translated from (Muniz 2011)

Table 9. Environmental Risk Assessment Codes.

Using the criteria for RAC as presented in Table 9, (Muniz 2011), it was drawn two hazard matrixes, one analyzing a platform in general (Table 10) and a second one analyzing the drilling system (Table 11), among others.

As a complex system, oil extraction platforms in an off-shore environment have a large number of areas and hazards to be dealt with. The data presented in Tables 10 and 11 are nothing but a small portion of the work developed by (Muniz 2011). Therefore, a HM is a remarkable tool to guide the risk assessment process, as well as, the team responsible for risk control and mitigation.

In the early stages of the risk management program, by the use of HM, several hazards can be ignored, sectors and areas of lower relevance percentages can be neglected and all the effort and resources can be oriented to those hazards and areas that represent the most relevant within this vast and complex system.



Nowadays modern society and economy is heavily dependent upon oil and its derivatives. From that, it is just logical to assume that oil industry is a major player within the international economy, being present worldwide, from prospection, extraction and processing. At the same time, oils are fuels and by that reason they represent a hazard to be managed. Even more, the large amounts of oil dealt with worldwide exponentially increases the hazard, both occupational (intense labor, heavy machinery, pumps, chemical hazards, fire hazard, and accidents in general.) and environmental (major fires, explosions, major

In a greater scope, there are the oil extraction operations off shore. Extraction platforms stationed off shore are one important representative of this group. These platforms are very complex installations, being capable to drill and build the oil wells, extract, produce and hold both oil and high pressure gases, as well as perform the entire set of required

Due to the off shore environment in which oil platform operate and the hazards of its operations and products dealt with, as well as economical relevance in modern society, they constitute an extremely important scenario for risk assessment, including hazard matrix ranking system. Muniz (2011) developed his work having an off-shore oil extraction platform as a case of study. The chosen platform is set at the Brazilian coast, near the city of

Using the criteria for RAC as presented in Table 9, (Muniz 2011), it was drawn two hazard matrixes, one analyzing a platform in general (Table 10) and a second one analyzing the

As a complex system, oil extraction platforms in an off-shore environment have a large number of areas and hazards to be dealt with. The data presented in Tables 10 and 11 are nothing but a small portion of the work developed by (Muniz 2011). Therefore, a HM is a remarkable tool to guide the risk assessment process, as well as, the team responsible for

In the early stages of the risk management program, by the use of HM, several hazards can be ignored, sectors and areas of lower relevance percentages can be neglected and all the effort and resources can be oriented to those hazards and areas that represent the most

**6.2 Oil Extraction – Offshore platform** 

maintenances (Freitas *et al* 2001; Booth and Butler,1992).

**Risk Assessment Code Description** 

Table 9. Environmental Risk Assessment Codes.

drilling system (Table 11), among others.

relevant within this vast and complex system.

Source: Translated from (Muniz 2011)

risk control and mitigation.

Exposition un-existence Low level of exposition. Medium Level of Exposition High Level of Exposition

The work performed by (Muniz 2011), the RAC used were as in table 9

leaks both in land and water).

Vitoria.


Source: Translated from (Muniz 2011) Table 11. Hazard Matrix – DRILLING SYSTEM

Hazard Matrix Application in Health, Safety and Environmental Management Risk Evaluation 47

Since Hazard Matrix is a prioritization tool, as it aims to provide a priority ranking among identified hazards and sectors, they must be previously identified and inserted in the HM. Therefore, HM utilization in combination with a Risk Identification tool, such as Preliminary Hazard Analysis (PHA) is essential. In this sense, failures in the risk identification phase, as well as the exclusion of some specific risk or sector identification will certainly jeopardize

Under the approach of decomposing risk into its independent variables, as discussed earlier, HM prioritization of hazards are intrinsically related to the factors severity and probability of occurrence. As HM prioritizes the most critical hazards, the ones whose product of severity x probability have a high value would be, at a first moment, a priority for the treatment phase highlighted by HM. However, at a second moment, after risks mitigation under the orientation of HM prioritization is done, hazards whose severity and probability were lower initially will appear as priorities in a second HM utilization. The transition happens because, during the risk mitigation phase, severity and probability factors of the most critical risks are reduced. Consequently, in a second HM utilization, they will not

In addition, even though the HM Environmental application provides an efficient alternative analysis, one of the most relevant limitations of the methodology is related to the difficulty to compare efficiently in prioritization terms both Environmental and

Besides, although HM provides a relative comparison between hazards or sectors that ordinates, in percentage, the most critical sectors/hazards to be prioritized, when the difference between percentages are very small, the differentiation of relevance between this sectors/hazards and its effects on the risks mitigation plans must be analyzed carefully, since this numerical analysis is relative. Therefore, in this situation, other factors that concern at these sectors/hazards must be evaluated and combined to the HM's result.

In this sense, the role of HM alternative applications, such as Project and Environmental presented earlier become a useful complementary analysis. By providing an auxiliary view of the global situation, they may compensate the conventional HM restrictions and

Some future aspects of the application of the HM methodology should be listed as: 1) a deeper study in the application of the weights used inside the HM; 2) improvements done in the data collection of hazards and sectors, in order to enhance the results achieved (having the burden of a higher price of investment) and 3) the development of a better integration between risks pertaining the occupational aspect of the analysis (said to be inside the walls)

As it stands, the HM concept and application in HSE is a powerful yet simple form of decision making in an occupational risk assessment. It is fully integrated in the Risk Management Program of any company. Resources and structure to do this are quite

limitations such as the ones listed above, reducing the probability of errors.

and those risks which expose a larger community (said to be outside the walls).

the accuracy and reach of HM prioritization results and global analysis.

appear in the top of priority ranking provided by the method.

Occupational risks in the same HM.

**8. Closure and future work** 

commonly already available.

**7. Limitations and aspects of hazard matrix** 

### **7. Limitations and aspects of hazard matrix**

46 Risk Management for the Future – Theory and Cases

Since Hazard Matrix is a prioritization tool, as it aims to provide a priority ranking among identified hazards and sectors, they must be previously identified and inserted in the HM. Therefore, HM utilization in combination with a Risk Identification tool, such as Preliminary Hazard Analysis (PHA) is essential. In this sense, failures in the risk identification phase, as well as the exclusion of some specific risk or sector identification will certainly jeopardize the accuracy and reach of HM prioritization results and global analysis.

Under the approach of decomposing risk into its independent variables, as discussed earlier, HM prioritization of hazards are intrinsically related to the factors severity and probability of occurrence. As HM prioritizes the most critical hazards, the ones whose product of severity x probability have a high value would be, at a first moment, a priority for the treatment phase highlighted by HM. However, at a second moment, after risks mitigation under the orientation of HM prioritization is done, hazards whose severity and probability were lower initially will appear as priorities in a second HM utilization. The transition happens because, during the risk mitigation phase, severity and probability factors of the most critical risks are reduced. Consequently, in a second HM utilization, they will not appear in the top of priority ranking provided by the method.

In addition, even though the HM Environmental application provides an efficient alternative analysis, one of the most relevant limitations of the methodology is related to the difficulty to compare efficiently in prioritization terms both Environmental and Occupational risks in the same HM.

Besides, although HM provides a relative comparison between hazards or sectors that ordinates, in percentage, the most critical sectors/hazards to be prioritized, when the difference between percentages are very small, the differentiation of relevance between this sectors/hazards and its effects on the risks mitigation plans must be analyzed carefully, since this numerical analysis is relative. Therefore, in this situation, other factors that concern at these sectors/hazards must be evaluated and combined to the HM's result.

In this sense, the role of HM alternative applications, such as Project and Environmental presented earlier become a useful complementary analysis. By providing an auxiliary view of the global situation, they may compensate the conventional HM restrictions and limitations such as the ones listed above, reducing the probability of errors.

#### **8. Closure and future work**

Source: Translated from (Muniz 2011) Table 11. Hazard Matrix – DRILLING SYSTEM

Some future aspects of the application of the HM methodology should be listed as: 1) a deeper study in the application of the weights used inside the HM; 2) improvements done in the data collection of hazards and sectors, in order to enhance the results achieved (having the burden of a higher price of investment) and 3) the development of a better integration between risks pertaining the occupational aspect of the analysis (said to be inside the walls) and those risks which expose a larger community (said to be outside the walls).

As it stands, the HM concept and application in HSE is a powerful yet simple form of decision making in an occupational risk assessment. It is fully integrated in the Risk Management Program of any company. Resources and structure to do this are quite commonly already available.

Hazard Matrix Application in Health, Safety and Environmental Management Risk Evaluation 49

Crippa, C., Fiorentini, L., Rossini, V., Stefanelli, R., Tafaro, S., & Marchi, M. (2009). Fire risk

Date, P. Lade, R.J. Mitra, G. E Moore, P.E. (2009). *Modelling the risk of failure in explosion* 

De Mello, C.H. (2004), *Uma Ferramenta Computacional para uso da Matriz de Relevância na* 

Fortuna, A. O. (2000). *Técnicas Computacionais para Dinâmica dos Fluidos: Conceitos Básicos* 

Fogler, H. S.; Elements of Chemical Reaction Engineering. *Prentice-Hall International Series in* 

Freitas, C.M., Souza, C.A., Machado, J.M et al. (2001). *Acidentes de trabalho em plataformas de petróleo da Bacia de Campos*, Cad. Saúde Pública, Rio de Janeiro, Brazil. Eds Frutuoso, P. F, Faertes, D. (2001). *Análise de Confiabilidade e Análise Quantitativa de Risco* – *Curso de Avaliação e Gerenciamento de Riscos* , Instituto Politécnico da UFRJ. Galante, E. B. F., Haddad, A. N. (2009). *Risk Analysis procedures for explosives manufacturing*.

Nota, G., Gregorio, M. P. D. (2010). *A Model for Process Oriented Risk Management, Advances in* 

Haddad, A.N., Morgado, C. V., & De Souza, D. I. (2008). Health, Safety and Environmental

International Standard Organization. (2009). Risk Management – Principles and Guidelines.

International Standard Organization. (2000). Sistemas de gestão da qualidade – Requisitos.

International Standard Organization. (2004). Sistemas da gestão ambiental - Requisitos com

Kletz T. A. (1988). *What Went Wrong? – Case Histories of Process Plant Disasters*, Gulf

Lees, F.P. (1996). Hazard Identification, Assessment, and Control, vols. 1–3, *Journal of Loss* 

Hanea, D., Ale, B. (2009). *Risk of human fatality in building fires: A decision toolusing* Bayesian

*Prevention in the Process Industries* Butterworth-Heinemann, Oxford

Hammer, W. (1972) *Handbook of System and Product Safety*. Prentice-Hall.

*Proceedings of the 2008 IEEE IEEM,* ISBN 978-1-4244-2630-0.

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Publishing Company, Texas, EUA

Meyer, R. (1977). Explosives. Gebr. Diesbach. Germany.

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*the Physical and Chemical Engineering Sciences*. IBSN 0-13-53708-8;

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Mathematics, Brunel University, Middlesex UB8 3PH, UK

Brazil.

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oriented-risk-managenent

ISO 31000:2009,

NBR ISO 9001: 2000,

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*protection installations*. Center for the Analysis of Risk and Optimisation Modelling Applications (CARISMA), School of Information Systems, Computing and

*Avaliação de Riscos Computacionais,* Universidade Federal Fluminense (UFF),

*e Aplicações*, Editora da Universidade de São Paulo, ISBN 85-314-0526-2, São

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*Risk Management*, Giancarlo Nota (Ed.), ISBN 978-953-307-138-1, InTech, Available from: http://www.intechopen.com/articles/show/title/a-model-for-process-

Management Risk Evaluation Strategy: Hazard Matrix Application Case Studies,

The strategic role of a risk prioritization stage at HSE is justified by the inherent limitation of resources with which any company works, as well as the difficulty to compare, in a relevance scale, predicted accidents. As shown in the first study case, human's impression of risk's relevance is not a reliable reference to make decisions and prioritize risk mitigation. In this context, the utilization of the HM, combined with some risk identification tool, such as Hazards Preliminary Analysis (HPA), enables such prioritization, ordering in a critical scale both sectors and hazards already identified and classified.

As there are different applications of HM, it is important to notice that their combined utilization with the original HM model is in a complementary approach. Thus, for the HSE of a company, for example, there can be developed both an occupational and an environmental Hazard Matrix. However, comparison between both environmental and occupational risks, in order to orient the prioritization of risk mitigation plans is still a challenge.

One may say that HM is the chosen method to prioritize risks and to determine strategic resources utilization within risk management. However, HM approach and effects transcend the mere aspect of risk prioritization: It must be considered as an efficient, global and multidisciplinary analysis, connected to plenty aspects of risk management, optimization and resources utilization.

#### **9. References**


The strategic role of a risk prioritization stage at HSE is justified by the inherent limitation of resources with which any company works, as well as the difficulty to compare, in a relevance scale, predicted accidents. As shown in the first study case, human's impression of risk's relevance is not a reliable reference to make decisions and prioritize risk mitigation. In this context, the utilization of the HM, combined with some risk identification tool, such as Hazards Preliminary Analysis (HPA), enables such prioritization, ordering in a critical scale

As there are different applications of HM, it is important to notice that their combined utilization with the original HM model is in a complementary approach. Thus, for the HSE of a company, for example, there can be developed both an occupational and an environmental Hazard Matrix. However, comparison between both environmental and occupational risks, in

One may say that HM is the chosen method to prioritize risks and to determine strategic resources utilization within risk management. However, HM approach and effects transcend the mere aspect of risk prioritization: It must be considered as an efficient, global and multidisciplinary analysis, connected to plenty aspects of risk management,

Australia. (2004). Australian and New Zealand Standards, AS NZS 4360:2004: *Risk* 

Brazil. Lei 6.938 de 31 de agosto de 1981 - Política Nacional de Meio Ambiente. Brasilia,

Bubbico, R.; Marchini, M. (2008). Assessment of an explosive LPG release accident: A

Ciocoiu C. N., Dobrea R. C. (2010). The Role of Standardization in Improving the

Giancarlo Nota (Ed.), ISBN 978-953-307-138-1, InTech, Available from: http://www.intechopen.com/books/show/title/advances-in-risk-

Centre for Environmental & Risk Management (CERM), School of Environmental Sciences,

Center for Chemical Process Safety of the American Institute of Chemical Engineers. (1989). *Guidelines for Chemical Process Quantitative Risk Analysis*. New York: CCPS. Clancy, VJ. (1972). Diagnostic Features of Explosion Damage, *6th International Meeting on* 

Committee For the Prevention of Disasters. (1997). Methods for Determining and processing

probabilities (RED BOOK). Netherlands. ISBN 90-12-08543-8

Case study. *Journal of Hazardous Material,* No 202, (2008), pp 558-565 , ISSN

Effectiveness of Integrated Risk Management. *Advances in Risk Management*,

University of East Anglia. (1997). *Risk Ranking*, Health & Safety Executive,

both sectors and hazards already identified and classified.

optimization and resources utilization.

*Management*. ISBN 0 7337 5904 1

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*Forensic Sciences*, Edinburgh, Scotland,.

**9. References** 

1981.

0304-3894

management

Norwich.

order to orient the prioritization of risk mitigation plans is still a challenge.


**3** 

*Greece* 

**The Deterministic and Stochastic Risk** 

**A FTA-TRF Case Study** 

P.K. Marhavilas and D.E. Koulouriotis *Democritus University of Thrace, Xanthi,* 

**Assessment Techniques in the Work Sites:** 

Occupational accidents have a major impact upon human integrity and they also create high costs for the social welfare system in a country. Furthermore, risk analysis is an essential process for the safety policy of a company, having as main aim the effacement of any potential of damage. The diversity in risk analysis approaches is such that there are many appropriate techniques for most circumstances and the choice has become more a matter of taste (Reniers *et al.*, 2005b). The risk assessment is an essential and systematic process for assessing the impact, occurrence and the consequences of human activities on systems with hazardous characteristics (Van Duijne *et al.*, 2008) and constitutes a needful tool for the safety policy of a company. We can consider risk as a quantity, which can be measured and expressed by a mathematical relation, under the help of real accidents' data. The risk assessment is generally achieved by a deterministic and/or a stochastic method. The first one is classified into three main categories; 1) the qualitative, 2) the quantitative, and 3) the hybrid techniques (qualitative-quantitative), while the second one includes the classic statistical approach and the accident forecasting modelling (Marhavilas, 2009a, 2009b; Marhavilas and Koulouriotis, 2007, 2008, 2011, 2012;

On the other side, few comparative studies have been performed on different stochastic and deterministic risk assessment methods. Thus, most researchers primarily focus on longitudinal surveys concerning an individual method (Zheng and Liu, 2009). However, an individual method cannot achieve the best risk-assessment result in the worksites, and future perspectives should focus on the parallel application of a deterministic (DET) and a

In fact, the contribution of the development and elaboration of STODET processes, to the

health and safety science, could be focused (Marhavilas and Koulouriotis, 2011) on:

**1. Introduction** 

Marhavilas *et al.*, 2011a, 2011b).

stochastic (STO) process (Marhavilas and Koulouriotis, 2012).

a. The *improvement* of the risk assessment techniques b. The *comparison* of their outcome risk estimation results c. The *enrichment* of the scientific literature with new tools

