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Risk‐based techniques such as risk graph and Layer of Protection Analysis (LOPA) are used to determine the Safety Integrity Level (SIL) of safety instrumented functions to ensure that risk is reduced to a tolerable level. However, these techniques have some drawbacks. For instance, they need absolute and precise numbers to evaluate SIL parameters, which are rarely available or are highly uncertain. In addition, they are incapable of considering individual and societal risks simultaneously. Moreover, risk tolerance criteria are likely to be used incorrectly in the LOPA technique, and risk graph is difficult to calibrate. In the current paper, a novel comprehensive fuzzy arithmetic model has been developed to determine the required SILs in process industries. The fuzzy required Risk Reduction Factor (RRF) is calculated for both individual and societal risks. Fuzzy numbers are developed from crisp intervals, based on the expected interval of the fuzzy numbers. Expert fuzzy‐scaled elicitation has been applied to obtain the SIL parameters. In the proposed model, the overall risk tolerance criterion and apportionment factor are defined as SIL parameters for both individual and societal risks to ensure that the applied risk criteria are compliant with the requirements of the system. In addition, an approach is introduced for determining the required SIL based on the fuzzy required RRF. The proposed methodology was demonstrated to alleviate the limitations, and thus, can be considered as a more precise alternative to the conventional methods. [ABSTRACT FROM AUTHOR]

Domino accidents are typical low-frequency and high-consequence events in chemical process industries. Applying quantitative risk assessment (QRA) in domino accident assessment is challenging due to the uncertainties in the escalation process. Meanwhile, the outcomes of QRA are subject to a certain degree of unreliability due to the inappropriate representation of uncertainty. This paper reviews the literature in the field of QRA of domino accidents that may happen in the chemical process industries. Firstly, the sources of uncertainty in risk assessment of domino effects are identified and categorized based on a fundamental structure of uncertainty and a QRA framework. Furthermore, the current methodologies and approaches applied for handling various uncertainties (input uncertainty, model parameter uncertainty, and model structure uncertainty) in the QRA related to domino effects are reviewed. Based on the literature review results, current challenges with respect to uncertainty handling in QRA of domino accidents are discussed, and recommendations for future research are given before the conclusions are presented. This study helps researchers to get insights into the interface between uncertainty fundamentals and the QRA framework and the current status of uncertainty handling in the QRA of domino effects. Furthermore, this study promotes the development of new approaches for handling uncertainty in domino accident analysis. [ABSTRACT FROM AUTHOR]

Chemical plants face safety hazards and security threats that may induce catastrophic scenarios. Safety and security barriers are employed widely to protect chemical plants from accidental and intentional undesired events and mitigate consequences. Managing safety and security barriers effectively and economically is a research topic with practical significance. The analysis of undesired event scenarios, including both accidental and intentional adverse scenarios, and assessing associated safety and security barriers are critical regarding cost-efficient barrier maintenance. This study proposes a novel approach for optimizing safety and security barrier maintenance strategy considering economic constraints. This approach consists of three steps: scenario building and barrier identification, barrier modeling, and determining optimal barrier maintenance intervals. In the proposed approach, accident scenarios in terms of safety and physical security are constructed using the extended bow-tie diagrams. After associated safety and security barriers are identified, a system simulation model is developed to conduct barrier modeling based on MATLAB/Simulink simulations, in which the barrier maintenance, the impacts of human and organizational barriers, and the correlations between barriers caused by shared components are considered. Finally, a combination of cost-effectiveness analysis (CEA) and genetic algorithm (GA) is employed to support the decision-making on barrier maintenance optimization. An illustrative case is employed in this study to validate the feasibility of the proposed approach. [ABSTRACT FROM AUTHOR]

Accidents resulting in industrial fires in chemical and process installations and in industrial parks where relevant quantities of hazardous substances are stored or processed may cause domino effects. Probit models developed and used in a multitude of studies can provide the probability of equipment failure, but they do not consider the effect of multiple radiation sources, and thus fail to capture the effects of severe scenarios as those where multiple fires start at different times in different units. In the present study, a critical thermal dose for equipment failure is defined. A direct procedure for the calculation of ttf based on the critical thermal dose is then introduced, which is able to account for the time at which the different secondary fires start or are extinguished. This allows considering the effects of the primary and of several secondary fire scenarios in causing a domino effect, updating the time to failure on the basis of the dynamic evolution of multiple fire scenarios. The proposed approach is demonstrated through case-studies addressing fire-induced domino effects in an oil storage tank farm. [ABSTRACT FROM AUTHOR]

OCI Nitrogen, one of Europe's largest fertilizer producers, is investigating the extent to which it is possible to take targeted measures at an early stage and stop the development of major hazard accident processes. An innovative model has been developed and recently explained and elaborated in a number of publications. This current paper contains a validation of the model by looking at the BP Texas City incident in 2005. The bowtie metaphor is used to visually present the BP Texas City refinery incident, showing the barrier system from different perspectives. Not only is the barrier system looked at from its trustworthiness on the day of the incident but also from the perspective of the control room operator, and from a design to current standards of best practice. The risk reductions of these different views are calculated and compared to their original design. In addition, evidence and findings from the investigations have been categorized as flaws and allocated to nine organizational factors. These flaws may affect the barrier system's quality or trustworthiness, or may act as 'accident pathogens' (see also Reason, 1990) creating latent, dangerous conditions. This paper sheds new light on the monitoring of accident processes and the barrier management to control them, and demonstrates that the BP Texas City refinery incident could have been foreseen using preventive barrier indicators and monitoring organizational factors. [ABSTRACT FROM AUTHOR]

Identifying critical installations in an area containing many chemical installations is important for the safety management of the chemical area. In this study, the area impact degree of chemical installations is defined, which is determined by analyzing the probability of accidents at other installations in the area when an accident occurs at a given installation, and the losses caused by each installation in the event of corresponding accident. Critical installations for area safety can be easily identified by comparing the area impact degree of different installations in the area. An illustrative example demonstrates the proposed approach. Analysis of the area impact degree of 6 tanks in a storage area and identification of more important installations for the safety of the entire area illustrate the applicability of this approach. Furthermore, our novel area importance analyzing approach is also compared with the graph approach. [ABSTRACT FROM AUTHOR]

OCI Nitrogen seeks to gain knowledge of (leading) indicators regarding the process safety performance of their ammonia production process. The current sub-study raises the question whether major hazard accidents in the ammonia production process can be predicted from organizational factors, also called management delivery systems. This paper links organizational factors to accident processes and their barrier systems, using the bowtie metaphor. It is shown that organizational factors indirectly impact accident processes as they strongly influence the quality or trustworthiness of the barrier systems. By putting the right focus on organizational factors during audits or reviews, major accident processes get the attention they deserve, and the necessary actions are taken at the right management level. Qualitative and quantitative monitoring of organizational factors can provide a picture of their operation and efficiency. Using an example on retrospective data it is demonstrated that information from organizational factors could have stopped the development of the near-accident prematurely. However, organizational factors should first be qualitatively assessed before they are quantitatively monitored. A quantitative assessment has been worked out for one of the management delivery systems so to provide an example of management indicators. Determining these (management) indicators from threshold values is an intricate matter due to the complicated influence of organizational factors on accident processes, and requires more follow-up research. [ABSTRACT FROM AUTHOR]

Emergency response plays an important role in preventing or delaying the domino effect of chemical accidents. Requirements for emergency response to a major accident may exceed the capacity of the emergency department within the region of responsibility for the accident, in which case multi-department emergency response is necessary. In this work, modeling problems related to the arrival of emergency teams at different times in multi-department emergency response are discussed. These problems will dynamically influence the time to failure of adjacent facilities in the event of a fire. A timed colored hybrid Petri-net (TCHPN) approach is proposed to solve these problems and analyze multi-department emergency response processes. An example of responding to a tank fire illustrates the proposed approach. An emergency response process is simulated, and probabilities of fire escalation prevention under different fire levels are analyzed. [ABSTRACT FROM AUTHOR]

Chemical industrial areas comprising various hazardous installations may be attacked by adversaries, triggering possible intentional domino effects. Compared with accidental domino effects, intentional domino effects may be more difficult to prevent since intelligent and strategic adversaries can adapt their tactics according to protection measures. However, how and to what extent domino effects affect security management is ignored in previous studies. This study proposes a methodology to prevent and mitigate intentional domino effects taking into consideration economic issues in the decision-making process on safety and security resources. The methodology is divided into five parts: threat analysis, vulnerability analysis of installations with respect to intentional attacks, vulnerability analysis of installations subject to possible domino effects caused by the attacks, cost-benefit analysis, and optimization. Net present value of benefits (NPVB) is employed and quantified in the cost-benefit analysis to determine whether a protection strategy (a combination of safety and security measures) is profitable, or not. Besides, an optimization algorithm called "PROTOPT" based on "maximin" strategy is developed to achieve the most profitable protection strategy. An illustrated case study shows that domino effects can not be ignored in security management since they may have a profound impact on adversaries' strategies. [ABSTRACT FROM AUTHOR]

• The study applied bibliometric in reviewing university laboratory safety research. • Most influential countries, journals, scholars, and papers were identified. • Cooperation among main research countries, institutions and authors were analyzed. • The research topics and trends were identified using terms co-occurrence network. • Several avenues for future research are proposed on university laboratory safety. Although there is a growing field of research focusing on university laboratory safety, accidents in such contexts still occur relatively frequently. Therefore, it is significant to summarize current research status and gaps, and to propose future research directions in the field of university laboratory safety. In this paper, a bibliometric analysis method was applied to gain an overall view of the developments, focus areas, and trends in this field of safety research. A total of 219 scientific publications on university laboratory safety were identified and screened from the database of Web of Science, covering 44 countries or regions, 254 research institutions, 575 authors, 126 publication sources, and 70 subject categories. Bibliometric data such as annual growth trend and distribution of subject categories were analyzed by using descriptive statistics. The most productive and influential countries, institutions, authors, and their cooperation networks were identified from co-citation maps created by VOSviewer. Further analysis was carried out to find out the core publications and publication sources in this field. Insights in the focus areas and research topics over time were obtained through terms co-occurrence analysis. The results indicate that university laboratory safety is a highly multidisciplinary research field. However, it is still a young discipline and belongs to the minority research field when compared with other safety domains. Several avenues for future research are identified to advance and make progress in this field. [ABSTRACT FROM AUTHOR]

Earthquake-triggered fire domino scenarios (E-FDSs) arise frequently from the interaction between earthquakes and chemical installations, resulting in catastrophic multi-hazard coupling events. The complicated mutually amplified phenomena between natural disasters and chemical accidents significantly aggravates the escalation of domino accidents, which has posed great challenges for modeling and preventing E-FDSs. Under this impetus, this work proposes an advanced type-2 fuzzy probabilistic methodology to obtain the time-dependent failure probability of steel cylindrical tanks (SCTs) subjected to the earthquake-fire sequence. To cope with the limited prior knowledge on E-FDSs, a basic universal is established to describe the fire resistance attenuation caused by the seismic damage. The coupling failure criterion of SCTs is formulated by a type-2 fuzzy time-dependent limit state equation. A credibility-based stochastic simulation algorithm is developed for the hybrid uncertainty analysis (combining ambiguity and stochasticity). The proposed methodology is validated by case studies of a 5000 m3 fixed roof tank. Compared to the existing accident probability model, the proposed methodology can not only capture the fire resistance attenuation caused by the seismic damage but also provide a dynamic estimation of tank failure probability with respect to the fire exposure time. The proposed methodology can effectively and dynamically capture the accident evolution process, which in turn helps mitigate and prevent the spatiotemporal propagation of domino effects. • Pivotal insights on the multi-hazard amplified phenomena are provided. • The time-dependent evolution of earthquake-fire coupling fragility is revealed. • An advanced multi-hazard dynamic coupling fragility methodology is proposed. • Hybrid uncertainty analysis combining ambiguity and stochasticity is achieved. • Dynamic fire failure interval of seismic damaged tanks can be identified. [ABSTRACT FROM AUTHOR]

Highlights • Provides a method to systematically investigate accidents in relation to analyzing elements of the SMS. • A socio-technical approach is adopted. • A graphical representation of the method is given. Abstract The concept of a safety management system (SMS) to control the risks of operational activities has been introduced in high-risk industries already some decades ago. SMS requires accidents/incidents to be reported and analysed and measures to be taken to prevent future events. Additionally, national investigating bodies have been given the role of independently investigating serious events, with the same goal. The current practice in accident and incident investigation however, does not provide a systematic approach to analyse elements of SMS. As a direct consequence, the opportunity to use these investigations for introducing sustainable system changes is often missed. The paper describes the SAfety FRactal ANalysis (SAFRAN) method that is developed to guide investigators to explore the composing elements of an SMS in a natural and logic way, starting from the findings close to operations that explain the occurrence – being the elements accident investigators are first confronted with. The paper further informs on the application of the SAFRAN method to review a selected set of published railway accident investigations, all reporting on occurrences related to over-speeding, possibly resulting in a (lethal) derailment. The depth and focus of the performed investigations is assessed and compared with a reference mode of expected findings that would result from an analysis that is applying the SAFRAN logic. This demonstrates the need, in order to introduce sustainable changes, to focus accident analysis on an organisation's capability of managing the variability that might put successful process performance at risk. [ABSTRACT FROM AUTHOR]

If flammable gas is mixed with air, and the mixture is ignited, it is possible to form a vapor cloud explosion (VCE) which may be very destructive, and easy to trigger a domino effect of accidents because of its large extent of impact. A VCE accident may induce secondary VCE accidents, then tertiary VCE accidents, and so on. This is called the cascading effect of VCE accidents, which requires an understanding of probabilities and propagation patterns to prevent and mitigate the potential damages. In this work, a methodology based on Petri-net is proposed to model the cascading effect of VCE accidents and perform probability analysis, taking the mutual influence between the accidents into account. The deficiency in probability analysis of VCE accidents is discussed. According to the limits of states and their changes which reflect characteristics of VCE propagation, a Petri-net approach is provided for modeling and analysis of VCE cascading effect, and the modeling approach and analysis process of VCE cascading effect are presented. The application and efficacy of the methodology are demonstrated via an example of VCE accidents occurring in a gasoline tank storage area. The results show that the developed methodology can effectively reveal the propagation patterns of VCEs cascading and calculate the respective probabilities of VCE accidents. [ABSTRACT FROM AUTHOR]

Security threats are becoming an increasing concern for chemical sites and related infrastructures where relevant quantities of hazardous materials are processed, stored or transported. In the present study, security related events that affected chemical and process sites, and related infrastructures, were investigated. The aim of the study is to frame a clear picture of the threats affecting the chemical and process industry, and to issue lessons learnt from past events. A database of 300 security-related accidents was developed and populated, starting from European and American sources. Threat categories that caused such events were identified and analyzed. The attack modes were investigated. Important differences were found with respect to geographical areas and industrial sectors affected. The use of explosives (both military and improvised explosive devices) is by far the more frequent attack mode, although armed attacks and arson are also frequent events and may result in an in-depth penetration of the attackers. In recent years, cyber-attacks are also posing important threats. Lessons learnt call for the implementation of a specific security management system in the chemical and process industry, aiming at the physical and cyber protection of industrial sites. [ABSTRACT FROM AUTHOR]

Knock-on effects or so-called domino effects in the process industries may cause much greater losses than merely a primary event. Probability analysis of accidents resulting from domino effects is important for risk assessment. However, for the accident occurrence of a unit there may be mutual influences between the units in the area influenced by the accidents due to a domino effect, and this makes the calculation of probabilities of the accidents rather difficult. A matrix-based approach is proposed to model the influences between units influenced by a fire-induced domino effects, and the analysis approach for accident propagation as well as a simulation-based algorithm for probability calculation of accidents is provided. The synergistic effect of thermal radiation is taken into account during the accident propagation. The proposed approach is flexible to model and analyze domino effects in various conditions of primary fires by only changing the value of the initial matrix indicating the fire states. Two examples illustrate analyzing the fire propagation among tanks storing flammable liquids. The results show that this approach is simple but effective for offering an insight in the accident propagation process and for knowing the probabilities of equipment getting on fire. [ABSTRACT FROM AUTHOR]

• A database of 300 security-related accidents in the chemical industry was populated. • Threats were analyzed with respect to geographical area and industrial sector. • Cyber-attacks were found to play a significant role in recent years. • Critical infrastructures are those where hazardous materials are stored. • Lessons learnt revealed the need for a robust security management system. Security threats are becoming an increasing concern for chemical sites and related infrastructures where relevant quantities of hazardous materials are processed, stored or transported. In the present study, security related events that affected chemical and process sites, and related infrastructures, were investigated. The aim of the study is to frame a clear picture of the threats affecting the chemical and process industry, and to issue lessons learnt from past events. A database of 300 security-related accidents was developed and populated, starting from European and American sources. Threat categories that caused such events were identified and analyzed. The attack modes were investigated. Important differences were found with respect to geographical areas and industrial sectors affected. The use of explosives (both military and improvised explosive devices) is by far the more frequent attack mode, although armed attacks and arson are also frequent events and may result in an in-depth penetration of the attackers. In recent years, cyber-attacks are also posing important threats. Lessons learnt call for the implementation of a specific security management system in the chemical and process industry, aiming at the physical and cyber protection of industrial sites. [ABSTRACT FROM AUTHOR]

Knock-on effects or so-called domino effects in the process industries may cause much greater losses than merely a primary event. Probability analysis of accidents resulting from domino effects is important for risk assessment. However, for the accident occurrence of a unit there may be mutual influences between the units in the area influenced by the accidents due to a domino effect, and this makes the calculation of probabilities of the accidents rather difficult. A matrix-based approach is proposed to model the influences between units influenced by a fire-induced domino effects, and the analysis approach for accident propagation as well as a simulation-based algorithm for probability calculation of accidents is provided. The synergistic effect of thermal radiation is taken into account during the accident propagation. The proposed approach is flexible to model and analyze domino effects in various conditions of primary fires by only changing the value of the initial matrix indicating the fire states. Two examples illustrate analyzing the fire propagation among tanks storing flammable liquids. The results show that this approach is simple but effective for offering an insight in the accident propagation process and for knowing the probabilities of equipment getting on fire. [ABSTRACT FROM AUTHOR]

In this paper, safety-related terms, factors and dimensions, such as safety climate, safety attitude, safety behaviour, safety technology, safety procedures, safety training, safety perception and others, are investigated from the perspective of safety culture. Based on an extensive review of literature regarding existing studies and models with respect to safety, an overall conceptual ‘big picture’ model of safety culture is developed and suggested. This model, called The Egg Aggregated Model, and abbreviated TEAM, provides a clear overview of how safety culture can be viewed in an organisation and how the different safety factors and dimensions constituting the safety culture are related in a cyclic way. [ABSTRACT FROM AUTHOR]

Recently, there have been several calls for increased attention to foundational issues in risk analysis, addressing issues like terminology, principles and theories. An important foundational issue is the appropriateness of different concepts and perspectives for analyzing risk in practical applications. Several authors have addressed this through arguments involving, inter alia, the definition of risk, the ontology of risk, and the reliability and validity of risk analysis. This paper aims to contribute to this discussion by focusing on the concept of prediction. While this term is quite frequently used in risk analysis contexts, no earlier work has specifically focused on the issue of whether risk analyses can be considered to be predictive, and if so, in what sense. Neither has this been linked to the feasibility of risk perspectives. First, two definitions of what prediction can mean are elaborated, and criteria corresponding to these definitions are outlined to facilitate the subsequent discussion. A brief discussion on system types is included, as one type of prediction is defined through the relation between the model and the modeled system. Then, the definitions of prediction and the corresponding criteria are used to consider the appropriateness of two commonly used risk perspectives, namely the probability of frequency and the uncertainty perspective. In the former, a risk analysis aims at estimating an underlying true risk with quantified uncertainty bounds. In the latter, a risk analysis is a descriptive account of judgments and uncertainties by an assessor. It is finally argued that the uncertainty perspective generally is more appropriate than the probability of frequency perspective for practical risk analysis applications. [ABSTRACT FROM AUTHOR]

As large amounts of hazardous chemicals are handled in the petrochemical industries, the plants in these industries are attractive for terrorists because they can cause great losses and have important social impact. Security risk assessment is important to determine the risk level of a plant in order to take targeted measures to reduce the security risk. Based on Security Risk Factor Table (SRFT) which covers the essential elements for the security risk assessment, a weighted fuzzy Petri-net (WFPN) based security risk assessment approach is proposed in this paper. This approach can easily model different relationships between the risk factors as well as their importance, and use the analysis method of Petri-nets to perform the risk assessment. Two WFPN models of security risk assessment are established according to different relationships between the factors, and a matrix operation based security risk inference method is developed. An illustrative example is used to demonstrate the approach. The results show that correctly determining and modeling the relationships among the risk factors is important to assess the security risk. [ABSTRACT FROM AUTHOR]

Land-use planning (LUP) has widely been employed as a protective safety measure in risk management of major hazard installations such as chemical plants. In the European Union countries, a majority of relevant work over the past years has been inspired by the Seveso II Directive. The inclusion of LUP in the Seveso II Directive has been with the aim of mitigating off-site damage of major accidents on public via setting criteria for (i) the identification of the location and layout of new installations, (ii) the development of existing installations, and (iii) the land developments in the vicinity of existing installations. We, in the present study, have proposed a methodology based on Bayesian network (BN) for cost-effective allocation of safety measures in chemical plants so that both internal and external risks could effectively be mitigated, particularly in compliance with the requirements of LUP. We first employed BN to calculate risks, and then extended the BN to a limited memory influence diagram using additional decision and utility nodes so that it can be used for multi-attribute decision analysis. The development and application of the methodology have been illustrated via fireproofing of a hypothetical fuel storage plant. [ABSTRACT FROM AUTHOR]

Several recent events raised the attention toward possible major accidents triggered by external acts of interference in industrial facilities. In particular, a growing concern is present with respect to the intentional release of dangerous substances resulting in environmental and eco-terroristic attacks. Therefore, optimal selection and allocation of preventive security measures is becoming more important for decision-makers. Despite the existence of economic models supporting the decision-making process, their applications within the chemical industry security context are relatively limited. This study describes a specific model for economic analysis and selection of physical security measures, with respect to potential environmental and eco-terroristic attacks in chemical facilities. An example of application to a relevant case study is presented to show the model capabilities. Site-specific analysis of the baseline physical security system performance allows comparing the costs of different security upgrades with the benefits related to either prospective or retrospective losses, meanwhile accounting the uncertainties related to the threat probability. Selection of the most profitable security measures within budget constraints and definition of economic indicators are the main outputs of the model, in order to support decision-making processes for allocation of security barriers. [ABSTRACT FROM AUTHOR]

Risk ranking is a widely used technique for selecting and prioritizing multiple risks facing an organization or decision maker. In industrial practice and in academic work, risk ranking methods are commonly based an implicit risk conceptualization, adopting a particular foundational perspective and accounting for selected factors. Nevertheless, different stakeholders may adhere to various risk conceptualizations, applying different foundational perspectives and accounting for different factors in the ranking process. Identifying a gap in the literature to coherently consider these different foundations, this paper presents an approach for reconciling different foundational perspectives and stakeholder views, accounting for uncertainties about these. The approach is presented based on three foundational perspectives (the expected value, uncertainty and moral perspective), and developed as a Bayesian Network – Influence Diagram. The main use of the model is to make possible controversies in risk prioritization explicit, facilitating stakeholder deliberation. The model can easily be extended with new perspectives on risk ranking, or adapted based on additional knowledge about other aspects, e.g. relating to risk perception. The graphical representation allows insights into the contribution of various aspects, facilitating the selection of appropriate risk management actions. The developed model is applied to an example, suggesting that the envisaged benefits of the proposed approach are plausible. It is concluded that the novel approach has a clear potential for reconciling different foundational perspectives and stakeholder views on risk ranking. Nevertheless, it is stressed that the conceptual contribution made in this paper should be more elaborately tested in practical settings, substantiating the findings further. [ABSTRACT FROM AUTHOR]

• The optimal allocation of emergency forces in front-line emergency response departments is studied. • The impact of emergency response on the time to failure of installations in the event of a fire accident is considered in the allocation. • A timed colored hybrid Petri-net (TCHPN) approach is proposed to model the emergency response process and analyze the allocation of emergency response forces. • A case study of the emergency response to a tank fire illustrates the proposed approach. Fire is one of the main accident scenarios occurring in chemical and process plants, and it can lead to domino effects due to thermal radiation. Emergency response is necessary to prevent fire escalation, in addition to safety barriers. In major industrial fire accidents, backup is usually required in emergency response, due to the lack of emergency response capacity of a single emergency response department. A method addressing the optimal allocation of emergency response forces, specifically considering the front-line departments, is developed in the present study. The emergency response of the front-line departments can reduce the thermal radiation received by the equipment adjacent to the primary fire and thus prolong the time to failure of the equipment, such that the backups have more time to get to the fire scene. The allocation analysis of emergency response teams is carried out considering the dynamic ttf of an adjacent equipment item resulting from the change in time of the thermal radiation received. A timed colored hybrid Petri-net (TCHPN) approach is proposed to model the emergency response process. The probability of preventing fire escalation is obtained from the TCHPN model and the optimal allocation of firefighting forces is determined. A case study illustrates the proposed approach, two scenarios are compared and results show that if a request for backup can be issued immediately according to the fire state, fewer emergency forces can be deployed on the front line department, such as the reduction from 6 emergency response teams to 3 teams to maintain the success probability of 0.91. The influence of other factors such as the position of fire departments and the layout of tanks on the allocation of emergency forces is also discussed. [ABSTRACT FROM AUTHOR]

In the context of domino effects, vulnerability analysis of chemical and process plants aims to identify and protect installations which are relatively more susceptible to damage and thus contribute more to the initiation or propagation of domino effects. In the present study, we have developed a methodology based on graph theory for domino vulnerability analysis of hazardous installations within process plants, where owning to the large number of installations or complex interdependencies, the application of sophisticated reasoning approaches such as Bayesian network is limited. We have taken advantage of a hypothetical chemical storage plant to develop the methodology and validated the results using a dynamic Bayesian network approach. The efficacy and out-performance of the developed methodology have been demonstrated via a real-life complex case study. [ABSTRACT FROM AUTHOR]

During an emergency response after an accident, emergency actions often require certain emergency resources. The adequate use, or the lack thereof, of emergency resources will affect the efficiency and even the success of emergency response activities or processes. Different emergency actions form certain relationships on using emergency resources. The cooperation modes of emergency actions on using resources are analyzed in this paper, and Petri-net models for these cooperation modes are provided. On this basis, an approach to detect emergency action conflicts resulting from resource-use is proposed. For conflicts caused by limited resources sharing, the queuing system which is modeled by a Petri-net and integrated into the model of emergency actions, is adopted to avoid conflicts. An example of an emergency response activity related with a fire accident is used to demonstrate the modeling method. The conflicts are analyzed and a queuing system is used to avoid simultaneously employing the same resource. [ABSTRACT FROM AUTHOR]

Emergency response actions can significantly influence the propagation of domino effects, particularly those triggered by fires. Thus, the performance and efficiency of devised emergency response actions should be carefully evaluated and taken into account when analyzing the propagation of domino effects and their risk. In the present study, we have introduced a methodology based on Event Sequence Diagram (ESD) to evaluate and prioritize different emergency response actions based on their efficiency in preventing or delaying the propagation of domino effect. Using the developed methodology, the risk of domino effects under emergency response actions can be assessed, while considering factors such as sequence, duration, correctness, and mutual interaction of the emergency response actions. We demonstrated the application of the methodology in analyzing the effect of emergency response actions on fire-induced domino effects in a fuel storage plant; the comparison of the results with previous studies illustrates the efficacy and practicality of the developed methodology. [ABSTRACT FROM AUTHOR]

Risk matrices and risk diagrams are widely used tools for analyzing, assessing and visualizing risk in many industries, and are used extensively for risk management purposes. Despite their popularity and wide application, they have recently become the object of discussion and research in scientific environments, which can be seen as part of a wider focus on foundational issues in the risk analysis discipline. Identifying several serious limitations and problems with the risk matrix approach, various authors have proposed extensions, modifications and recommendations for their use. One issue which has been raised recently but has attracted relatively limited scientific attention is the consideration of uncertainty in risk diagrams, i.e. how to visually represent and communicate uncertainty. This paper first reviews the available proposals for this question. Subsequently, the strengths and weaknesses of these proposals are discussed. Finally, some new proposals are made on how to represent uncertainty in risk diagrams in practical applications. [ABSTRACT FROM AUTHOR]

To improve risk informed decision making, a systematic approach is developed. The goal is to analyze and to evaluate safety investments aimed at mitigating and preventing major accidents involving e.g. hazardous materials that might trigger significant financial losses and fatalities. A formulation, explicitly using a disproportion factor, is proposed as a simulation exercise approach to this end. The disproportion factor can be used by any private and public investor to bias decision-makers toward safety. This is especially interesting for deciding about the prevention of high impact low probability (HILP) accidents. Furthermore experimental simulations have been performed on realistic data to test the proposed decision model and to provide general recommendations. Several types of accidents were considered and the impacts of technical and financial parameters on the disproportion factor, possibly making a safety investment profitable from an economic perspective, are also investigated and discussed in this paper. [ABSTRACT FROM AUTHOR]

Land use planning (LUP) as an effective and crucial safety measure has widely been employed by safety experts and decision makers to mitigate off-site risks posed by major accidents. Accordingly, the concept of LUP in chemical plants has traditionally been considered from two perspectives: (i) land developments around existing chemical plants considering potential off-site risks posed by major accidents and (ii) development of existing chemical plants considering nearby land developments and the level of additional off-site risks the land developments would be exposed to. However, the attempts made to design chemical plants with regard to LUP requirements have been few, most of which have neglected the role of domino effects in risk analysis of major accidents. To overcome the limitations of previous work, first, we developed a Bayesian network methodology to calculate both on-site and off-site risks of major accidents while taking domino effects into account. Second, we combined the results of risk analysis with Analytic Hierarchical Process to design an optimal layout for which the levels of on-site and off-site risks would be minimum. [ABSTRACT FROM AUTHOR]

Process- and chemical plants may constitute a critical target for a terrorist attack. In the present study, the analysis of industrial accidents induced by intentional acts of interference is carried out focusing on accident chains triggered by attacks with home-made (improvised) explosives. The effects of blast waves caused by improvised explosive devices are compared with those expected from a net equivalent charge of TNT by using a specific methodology for the assessment of stand-off distances. It is demonstrated that a home-made explosive device has a TNT efficiency comprised between 0.2 and 0.5. The model was applied to a case study, demonstrating the potentiality of improvised explosives in causing accident escalation sequences and severe effects on population and assets. The analysis of the case-study also allowed obtaining suggestions for an adequate security management. [ABSTRACT FROM AUTHOR]

Dealing with large quantities of flammable and explosive materials, usually at high-pressure high-temperature conditions, makes process plants very vulnerable to cascading effects compared with other infrastructures. The combination of the extremely low frequency of cascading effects and the high complexity and interdependencies of process plants makes risk assessment and vulnerability analysis of process plants very challenging in the context of such events. In the present study, cascading effects were represented as a directed graph; accordingly, the efficacy of a set of graph metrics and measurements was examined in both unit and plant-wide vulnerability analysis of process plants. We demonstrated that vertex-level closeness and betweenness can be used in the unit vulnerability analysis of process plants for the identification of critical units within a process plant. Furthermore, the graph-level closeness metric can be used in the plant-wide vulnerability analysis for the identification of the most vulnerable plant layout with respect to the escalation of cascading effects. Furthermore, the results from the application of the graph metrics have been verified using a Bayesian network methodology. [ABSTRACT FROM AUTHOR]

• Reliability analysis of emergency response is carried out based on time analysis. • Cooperation modes of emergency response actions and their time characteristics are analyzed. • A timed colored Petri-net (TCPN) based approach is proposed to model the cooperation of emergency actions. • Simulations are performed and the probabilities of preventing fire escalation under different cooperation modes are analyzed. Emergency response is an important way to reduce losses after a major industrial accident occurs and mitigation measures should be arranged and analyzed in preparedness. The cooperation in emergency response actions which make up an emergency response process has a significant impact on the efficiency and success rate (or reliability) of emergency response, and improper arrangement of actions may reduce emergency response efficiency. As emergency response is characterized by rapid response, this work studies the success of emergency response based on time analysis. In this paper, cooperation modes of emergency response actions and their time characteristics are analyzed. A timed colored Petri-net (TCPN) based approach is proposed to model the cooperation of the actions and perform time analysis. The proposed approach is illustrated by an example of fire brigades' response to a tank fire. Simulations are performed and the probabilities of preventing fire escalation under different cooperation modes are analyzed. TCPN based modeling and analysis of emergency response actions are helpful for planning the necessary actions in the preparation of an emergency situation. [ABSTRACT FROM AUTHOR]

In this paper we present a multi-modal security-transportation model to allocate security resources within a chemical supply chain which is characterized by the use of different transport modes, each having their own security features. We consider security-related risks so as to take measures against terrorist acts which could target critical transportation systems. The idea of addressing security-related issues, by supporting decisions for preventing or mitigating intentional acts on transportation infrastructure, has gained attention in academic research only recently. The decision model presented in this paper is based on game theory and it can be employed to organize intelligence capabilities aimed at securing chemical supply chains. It enables detection and warning against impending attacks on transportation infrastructures and the subsequent adoption of security countermeasures. This is of extreme importance for preventing terrorist attacks and for avoiding (possibly huge) human and economic losses. In our work we also provide data sources and numerical simulations by applying the proposed model to a illustrative multi-modal chemical supply chain. [ABSTRACT FROM AUTHOR]

Previous studies have demonstrated that reading and following safety instructions, such as warning labels and product manuals, may serve as a defense against hazards and can prevent injuries. This paper examines the predictive value of four factors that might determine whether students read and follow safety instructions: students’ safety norm, students’ safety attitude, the sensation seeking trait and type A personality. Our investigation was carried out with 172 university students (mean age = 20.01, SD = 1.56) who participated in a paper-and-pencil survey. Regression analyses revealed that students’ safety norm and attitude were positively related to reading and following safety instructions, while sensation seeking was inversely related. Type A personality had no predictive value. Our statistical findings further revealed that female students read and follow more safety instructions than male students. Based on these research results, recommendations are formulated. [ABSTRACT FROM AUTHOR]

Chemical industrial areas or so-called chemical dusters consist of hundreds, and sometimes thousands, of chemical installations situated next to each other. Such areas can thus be seen as the summation of a large number of structures exhibiting danger to a certain degree for initiating or continuing accident domino effects or knock-on effects. In this article, an approach to investigate in a systemic way the vulnerability of each installation within the larger chemical cluster context, is developed. Our suggested method results in a prioritization of chemical installations with respect to their vulnerability for domino effects. The method can be used for intelligently designed protection of chemical industrial areas against terrorist attacks. [ABSTRACT FROM AUTHOR]

Liquid storage tanks play a vital role in the modern chemical process industry (CPI). The strong ground motion caused by large-scale earthquakes may easily impose severe structural damage on liquid storage tanks, leading to a series of catastrophic cascaded events. The seismic damage estimation of liquid storage tanks is a challenging problem, as the fluid-structure interaction exhibits extremely complicated and non-stationary response behavior. This study develops a novel data-driven methodology to estimate the seismic damage state probability distribution of liquid storage tanks in the contexts of label ambiguity and data imbalance. With the support of the advanced deep learning framework, synthetic oversampling methods, and label enhancement techniques, a hybrid deep belief network-based label distribution learning system (HDBN-LDLS) is proposed for probability distribution learning. The proposed HDBN-LDLS is evaluated on the widely used ALA database. Simulation results indicate that HDBN-LDLS can achieve a balanced estimation for all damage states while maintaining sufficient robustness to cope with label ambiguity. The reliability of the obtained data-driven model is validated by a damaged tank in the 2006 Silakhor earthquake. For practical applications, a more natural way to estimate a seismic damaged tank is to assign a membership degree to each possible damage state. The proposed methodology can quickly obtain the seismic damage state probability curves of a specific liquid storage tank, which can be used to support quantitative risk assessment and seismic design. [ABSTRACT FROM AUTHOR]

Abstract: The current overload of sustainability standards as well as the oversimplification of traditional management systems are two factors which often prevent organizations from translating their sustainable aspirations into their core strategy. In this context and in view of a strategic and profound embedding of the CSR-concept, this study proposes a conceptual CSR framework, mainly on the basis of the recently published umbrella guideline ISO 26000. The proposed model for practice goes beyond the limitations of traditional PDCA cycles, through applying interconnected soft and hard factors as building blocks within a circular framework, thereby aiming to reduce the gap between the execution of loose sustainable initiatives and the application of a sustainability balanced scorecard. The framework has been named ‘Sus5’, as it connects five inherent features of sustainable business (management knowledge & commitment, stakeholder knowledge & commitment, strategic planning, knowledge & commitment on the work floor, and operational execution & monitoring). The added empirical study, which has been executed within the Flemish business landscape, reflects on the average Flemish as-is attention for each independent proposed building block, thereby aiming to retrieve in which extent the attention areas of the average company are aligned with the ones of Sus5 as the basis for drawing conclusions on the general feasibility level of applying Sus5. Through its intuitive and pragmatic character, Sus5 might in this context firstly serve as a practical tool for organizations to undertake a self-assessment and detect possible gaps in their CSR-policy, secondly to motivate them to shift the emphasis to a broader set of attention areas, based on the realization that a thorough CSR policy consists of a set of interdependent building blocks, being bonded by causal relations. [Copyright &y& Elsevier]

In this paper, we first derive a model from literature providing insights into the influence of different aspects of safety on each other, that is, knowledge, perception, attitude, behavior and its consequences. We called it the “KPABC model”. An experiment was furthermore designed and carried out to investigate the impact of laboratory safety interventions with students, and on the different safety aspects of the KPABC model. We finally explain the research results, and based on the findings, we provide recommendations on how to improve safety within higher education chemical labs. [ABSTRACT FROM AUTHOR]

Highlights: [•] Cultural differences between similar countries independently predict future risk of fatal work injuries. [•] The cultural dimensions Power Distance Index and Individualism are both significantly correlated with fatal work injuries. [•] Self-leadership and transformational leadership successfully decrease fatality numbers in countries and organizations. [ABSTRACT FROM AUTHOR]

• The KAB-model is empirically evaluated regarding security awareness among employees. • Employees with more security knowledge also have better attitudes towards security. • Employees with more security knowledge and better attitudes indicate to behave in a more secure way. • Awareness trainings have a strong impact on participants' security knowledge and attitudes. • More interactive trainings are needed to influence participants' secure behaviour. Today, the need to deal with workplace security threats has become an important matter for many organisations. While companies have invested in technological and organization measures, the human processes behind these techniques are often ignored. However, employees' awareness of security procedures and policy of the organisation may strengthen or weaken the implemented security measures. This article assessed in an empirical way employees' security awareness and has a twofold aim. First, a study was conducted to examine the associations between three dimensions of employees' security awareness. By the use of a survey (n = 1,443; mean age = 42.5; 60.4% female, 30.4% male), the relationship between employees' knowledge about security procedures and policy, the attitudes towards security and the self-reported security behaviour is measured. Second, a case study was carried out to examine the impact of training sessions on employee's level of security awareness. By organizing an awareness training, its effect on employees' knowledge, attitude and behaviour was measured (n = 74; mean age = 51.7; 70.3% female, 29.7% male). While the first study found a significant relationship between employees' knowledge and attitude and their self-reported behaviour, the second study showed that the training session had a positive effect on employees' level of security awareness. Based on the findings from both studies, recommendations for practice and future research are presented. [ABSTRACT FROM AUTHOR]

Abstract: This paper is a discussion paper and consists of two parts: first an introduction by the Associate Editor Genserik Reniers discussing the reason behind this article and classifying such a type of paper, and second the contribution by Terje Aven, with following abstract: The application of probability is of paramount importance for the risk and safety fields. But few of the papers in these fields explain what the probabilities introduced mean. The rules of probability are referred to, but very rarely do we see the authors of these papers defining or reflecting on how the probabilities are to be understood. The justification for this practice is that the scientific contributions mainly relate to computation of probability, and the calculus is independent of the interpretations. However, if the probabilistic analysis is to be implemented in practice, the meaning of the probabilities is essential. The probability numbers then have to be communicated, and it must be clear what a probability of 0.2 means compared to (say) 0.3. The purpose of the present paper is to point to the main alternative interpretations available and provide arguments for the use of some of these and the rejection of others, in a risk and safety context. Special focus is placed on subjective probabilities and what is referred to as value-based interpretations of such probabilities (which include betting and utility-based definitions). A main aim of the paper is to argue against these value-based interpretations and for the use of subjective probabilities understood with a reference to an uncertainty standard such as an urn, as strongly advocated by Dennis Lindley for more than 30years. Many probabilists are unfamiliar with this interpretation of probability. [Copyright &y& Elsevier]

Abstract: Using an online survey, we asked safety researchers around the globe how they perceived the quality of a list of 35 representative safety journals. We found that the most well-respected journal by expert opinion was the Journal of Loss Prevention in the Process Industries. However, taking both the respondents’ results and the citation-based results into consideration, the Journal of Hazardous Materials is the most influential journal, followed by Reliability Engineering and System Safety, Risk Analysis, Accident Analysis and Prevention and Safety Science. [Copyright &y& Elsevier]

A domino effect triggered by a natural event (a so-called Natech domino effect) represents a typical high-impact low-probability (HILP) event, which may lead to catastrophic consequences. The presence of safety barriers could have an impact on the effects by impeding propagation patterns and mitigating potential consequences. However, coordinating and maintaining safety measures to establish an effective barrier system against Natech domino effects is complicated. In this paper, the concept of what constitutes a safety barrier and the principles of barrier management are reviewed. Subsequently, the complex phenomenon of Natech domino effects is studied at the individual installation level, while the propagation pattern is explored at the system level. The application of safety barriers is discussed with the aim of coping with potential Natech domino effects. A systematic framework of barrier management is developed to establish and improve the barrier system in the whole cycle (design & construction, operation, accident, recovery & improvement) of a chemical industrial area. The challenges are discussed to highlight future study needs. [ABSTRACT FROM AUTHOR]

Abstract: The presented Multi-plant Collaboration Model uses game theory to evaluate different strategic cross-plant precaution collaboration situations. The model first assumes prevention management''s perceptions as a premise to take cross-plant prevention decisions. Second, it employs information from the different plants and aggregates the data to determine possible financial collaboration benefits within the entire industrial area. By doing so, an application of the model by a suggested independent supra-plant council may enhance and realize cross-corporation precaution in chemical clusters. [Copyright &y& Elsevier]

Abstract: This article discusses an innovative approach to measure and to enhance a company’s safety culture and climate as well as its security culture and climate in one go. A safety and security culture and climate model using three dimensions (People, Procedures and Technology) is suggested to form the building blocks of the model. The Improvement Diamond for Excellence Achievement and Leadership in Safety and Security (abbreviated IDEAL S&S) model’s structure is shaped by integrating the principles of Performance Management into the well-known and much used concept of the PDCA cycle or loop of continuous improvement. This way, the model can easily be used and implemented by any organization. Furthermore, a Roadmap is provided for introducing and applying the model and the approach to test the model in a real industrial setting is explained and discussed. [Copyright &y& Elsevier]

Abstract: The present paper provides a game theoretic analysis of strategic cooperation on safety and security among chemical companies within a chemical industrial cluster. We suggest a two-stage sequential move game between adjacent chemical plants and the so-called Multi-Plant Council (MPC). The MPC is considered in the game as a leader player who makes the first move, and the individual chemical companies are the followers. The MPC''s objective is to achieve full cooperation among players through establishing a subsidy system at minimum expense. The rest of the players rationally react to the subsidies proposed by the MPC and play Nash equilibrium. We show that such a case of conflict between safety and security, and social cooperation, belongs to the ‘coordination with assurance’ class of games, and we explore the role of cluster governance (fulfilled by the MPC) in achieving a full cooperative outcome in domino effects prevention negotiations. The paper proposes an algorithm that can be used by the MPC to develop the subsidy system. Furthermore, a stepwise plan to improve cross-company safety and security management in a chemical industrial cluster is suggested and an illustrative example is provided. [Copyright &y& Elsevier]

Abstract: The paper develops a methodology for assessing the relative risk levels in moving hazardous materials by various transport modes. Transportation Risk ANalysis tool for hazardous Substances (TRANS) divides routes into smaller segments using multi-criteria analysis and likelihood scores of accidents in which dangerous cargoes are involved possibly causing fatalities. The consequences of accident scenarios are calculated in terms of the number of people within 1% of the lethal distance from the accident centre. This provides a user-friendly, semi-quantitative risk analysis tool. The generic method allows for comparing the risk levels of the segments of routes used in the transportation of hazardous goods. [ABSTRACT FROM AUTHOR]

Abstract: Based on literature, we identify collaboration drivers and partner features for enhancing vertical and/or horizontal collaboration in the chemicals using industries. We further develop constructs for both types of collaboration. A survey-based analysis within the largest chemical cluster worldwide was carried out to verify and to test our literature-based constructs. Using our empirically based results, we develop and propose a framework for Advancing and Stimulating Collaboration (ASC) in the chemical industry. This framework can be used to increase collaborative arrangements within the chemical industry and thereby lead to more sustainable chemical product and process flows and management practices resulting in more sustainable chemical industrial parks. [ABSTRACT FROM AUTHOR]