Occupational Cognitive Failures and Safety Performance in the Workplace

Introduction. The majority of industrial accidents occur because of human errors. Human error has different causes, however, in all cases cognitive abilities and limitations of human play an important role. Occupational cognitive failures are cognitively-based human errors that occur at work. The aim of this study was to examine the relationship between occupational cognitive failures and safety consequences. Method. Personnel of a large industrial company in Iran filled out an occupational cognitive failure questionnaire (OCFQ) and answered questions on accidents. Univariate and multiple logistic regression analysis were used to determine the relationship between cognitive failures and safety consequences. Results. According to developed regression models, personnel with a high rate of cognitive failure, in comparison to low rate, have a high risk of minor injury involvement (OR 5.1, 95% CI [2.62, 10.3]); similar results were for major injury and near miss. Discussion. The results of this study revealed usefulness of the OCFQ as a tool of predicting safety-related consequences and planning preventive actions.     

Assessment of Safety and Health in the Tea Industry of Barak Valley,Assam: A Fuzzy Logic Approach

Traditional safety and health system measurement procedures, practiced in various industries produce qualitative results with a degree of uncertainty. This paper presents a fuzzy-logic-based approach to developing a fuzzy model for assessing the safety and health status in the tea industry. For this, the overall safety and health status at a tea estate has been considered as a function of 4 inputs: occupational safety, occupational health, behavioral safety and competency. A set of fuzzy rules based on expert human judgment has been used to correlate different fuzzy inputs and output. Fuzzy set operations are used to calculate the safety and health status of the tea industry. Application of the developed model at a tea estate showed that the safety and health status belongs to the fuzzy class of good with a crisp value of 7.2.     

基于三角模糊理论的尾矿库风险评价研究

根据尾矿库的特点和我国现行的尾矿库安全生产监督管理法律法规及标准规范的要求,构建了尾矿库风险评价指标体系。综合考虑评价指标对风险发生可能性及后果严重程度的不同影响来确定指标权重,同时考虑到权重确定和指标赋值中的模糊性和不确定性等问题,选用三角模糊理论建立了尾矿库风险评价模型,并以本溪某尾矿库为例进行说明。理论分析和实例计算表明,该方法对尾矿库风险评价有很好的适用性。     

AFRA – Heuristic expert system to assess the atmospheric risk of sulphide waste dumps

In 2006, an unprecedented atmospheric confined space accident took place in a sampling shed at the Sullivan Mine in Kimberley, British Columbia. This accident suggests that a risk assessment should be carried out on a regular basis at mine reclamation sites for many years after closure. In this paper, an Atmospheric Fuzzy Risk Assessment (AFRA) tool is described that can assess atmospheric risk given heuristic and measured data at such sites. It can also serve to transfer knowledge about atmospheric hazards in an enclosed structure. The system uses fuzzy logic to input and output information and to perform weighted inferencing. The paper describes the developmental process as well as system verification and validation based on a number of known test and reference waste dumps. AFRA is a heuristic expert system based on fuzzy logic and the first tool that was developed to assess the atmospheric risk of mine waste dumps. The atmospheric risk is estimated by fuzzy Mamdani system given the values of four major elements of risk comprising of: gas generation, gas emission, gas confinement, and human exposure. The ability of AFRA to adapt its risk assessment to different climate conditions is explained. There are many physical, chemical, and environmental factors which fluctuate over time affecting oxygen-depletion in waste dumps. AFRA can help mining engineers and mine managers recognize this type of danger when conducting a confined space inventory at a reclamation site.     

Multiple dimensions of work-related risk factors and their relationship to work ability among industrial workers in Iran

Objectives. The present study was designed to investigate the simultaneous effects of physical, psychosocial and other work-related risk factors on the work ability index (WAI) score among industrial workers. Methods. This study used a cross-sectional design with a questionnaire survey. A total of 280 workers were included in the study. Data were collected using three questionnaires including the Persian version of the WAI, the Persian version of the job content questionnaire and an author-developed measure (to assess work-related factors, health-related factors and socio-demographic characteristics). Results. The majority of the participants were young, but they had poor WAI scores (mean 37.3?±?6.4) and 44.3% of them had poor or moderate work ability. Occupational accidents and injuries were found to be the strongest predictors of WAI scores. Additionally, there was a strong association between WAI scores and supervisor support, skill discretion, occupational training, sleep quality, work nature and educational level. Conclusions. Intervention programs should focus on improving supervisor support, sleep quality, job skills and knowledge and on decreasing physical and mental work demands. Additionally, implementing a comprehensive occupational health and ergonomics program for controlling and reducing hazardous working environments and occupational injury rates should be considered.     

Methodology for the quantification of toxic dispersions originated in warehouse fires and its application to the QRA in Catalonia (Spain)

A tool for the quantification of the consequences of toxic dispersions coming from fires in warehouses has been developed. This tool is expected to be applied in the framework of the risk assessment in Catalonia, specifically in the Quantitative Risk Assessment. The present study is based on the criteria gathered in the technical guide BEVI 3.2 and the methodology CPR-15 used in the Netherlands. Hence, the approach performed accepts the main body of the foresaid methodology but implements a different and free source dispersion model, a modified Gaussian model that takes into account the warehouse effect. In the work conducted, a historical analysis of accidents involving fire in warehouses has been performed in order to justify the importance of assessing their potential toxic dispersions. Furthermore, the tool has been tested in different case studies providing results that have been compared with other methodologies, observing similar results that can be useful for the stakeholders and decision makers in the framework of the risk assessment.     

Computer-aided assessment of occupationally healthier processes during research and development stage

Each year more people die from occupational related diseases than are killed in industrial accidents. Therefore it is critical to start considering health aspect early when developing a new chemical process. In this paper, a computer-aided tool for assessing inherent occupational health is proposed for chemical process research and development stage. The method was developed based on the reaction chemistry data, which is the only data available at this stage. Three types of approaches were formulated to calculate the route index value using additive type, average type and worst case type calculations. The tool can be used to rank the alternative chemical synthesis routes by their health properties as well as characterize the hazard level of single process. Finally the tool was applied to six process routes for methyl methacrylate production for demonstration. The case study revealed hazards of the processes from different perspectives, e.g. the results from the additive-type calculation were mainly affected by the total number of steps in the route, which indicates the impact of process complexity on the level of hazard. The introduction of such tool provides a swift yet reliable means that will encourage health criteria to be considered earlier in process development besides economic, safety and environment.     

Dynamic probability assessment of urban natural gas pipeline accidents considering integrated external activities

Urban gas pipelines usually have high structural vulnerability due to long service time. The locations across urban areas with high population density make the gas pipelines easily exposed to external activities. Recently, urban pipelines may also have been the target of terrorist attacks. Nevertheless, the intentional damage, i.e. terrorist attack, was seldom considered in previous risk analysis of urban gas pipelines. This work presents a dynamic risk analysis of external activities to urban gas pipelines, which integrates unintentional and intentional damage to pipelines in a unified framework. A Bayesian network mapping from the Bow-tie model is used to represent the evolution process of pipeline accidents initiating from intentional and unintentional hazards. The probabilities of basic events and safety barriers are estimated by adopting the Fuzzy set theory and hierarchical Bayesian analysis (HBA). The developed model enables assessment of the dynamic probabilities of consequences and identifies the most credible contributing factors to the risk, given observed evidence. It also captures both data and model uncertainties. Eventually, an industrial case is presented to illustrate the applicability and effectiveness of the developed methodology. It is observed that the proposed methodology helps to more accurately conduct risk assessment and management of urban natural gas pipelines.     

Occupational injuries and sick leaves in household moving works

Background. This study is concerned with household moving works and the characteristics of occupational injuries and sick leaves in each step of the moving process. Methods. Accident data for 392 occupational accidents were categorized by the moving processes in which the accidents occurred, and possible incidents and sick leaves were assessed for each moving process and hazard factor. Results. Accidents occurring during specific moving processes showed different characteristics depending on the type of accident and agency of accidents. The most critical form in the level of risk management was falls from a height in the ‘lifting by ladder truck’ process. Incidents ranked as a ‘High’ level of risk management were in the forms of slips, being struck by objects and musculoskeletal disorders in the ‘manual materials handling’ process. Also, falls in ‘loading/unloading’, being struck by objects during ‘lifting by ladder truck’ and driving accidents in the process of ‘transport’ were ranked ‘High’. Conclusion. The findings of this study can be used to develop more effective accident prevention policy reflecting different circumstances and conditions to reduce occupational accidents in household moving works.     

Developing a new fuzzy inference system for pipeline risk assessment

The problem of less and/or even lack of information and uncertainty in modeling and decision making plays a key role in many engineering problems; so that, it results in designers and engineers could not reach to sure solutions for the problems under consideration. In this paper, an application of the fuzzy logic for modeling the uncertainty involved in the problem of pipeline risk assessment is developed. For achieving the aim, relative risk score (RRS) methodology, one of the most popular techniques in pipeline risk assessment, is integrated with fuzzy logic. The proposed model is performed on fuzzy logic toolbox of MATLAB^® using Mamdani algorithm based on experts' knowledge. A typical case study is implemented and a comparison between the classical risk assessment approach and the proposed model is made. The results demonstrate that the proposed model provides more accurate, precise, sure results; so that, it can be taken into account as an intelligent risk assessment tool in different engineering problems.     

基于风险等值线的职业安全评价分级方法

依据危害因素引发工伤、职业危害事件的后果严重度和可能性来开展职业安全评价,在严重度和可能性的定量评价基础上,引入等值风险线的概念,建立风险评价分级方法,并在单一危害因素的职业安全评价基础上建立了作业场所、工厂、企业的职业安全(风险)评价分级方法.通过应用实例分析,验证了该方法的可操作性.     

Reference criteria for the identification of accident scenarios in the framework of land use planning

Land use planning (LUP) around industrial sites at risk of major accidents requires the application of sound approaches in the selection of credible accident scenarios. In fact, the ‘technical’ phase of LUP is based on the identification and assessment of relevant accident scenarios. An improper choice of scenarios may critically affect both the ‘technical’ phase of risk assessment and the following ‘policy’ phase concerning decision making on land-use restrictions and/or licensing. The present study introduces a procedure aimed at the systematic identification of reference accident scenarios to be used in the gathering of technical data on potential major accidents, which is a necessary step for LUP around Seveso sites. Possible accident scenarios are generated by an improved version of the MIMAH methodology (Methodology for the Identification of Major Accident Hazards). The accident scenarios are then assessed for LUP relevance considering severity, frequency and time scale criteria. The influence of prevention and mitigation barriers is also taken into account. Two applications are used to demonstrate the proposed procedure. In both case-studies, the proposed methodology proved successful in producing consistent sets of reference scenarios.     

A cascaded fuzzy-LOPA risk assessment model applied in natural gas industry

Natural gas plants demand high amount of energy provided through immense fuel gas units that may suffer risk hazards. Implementing a safety management system is the most efficient way of allocating resources for safety. This paper adopts The Layer of Protection Analysis (LOPA) risk Management associated with Fuzzy Logic methodology to prevent or limit industrial accidents. We provide an innovative cascaded fuzzy-LOPA model for certain hazardous scenarios and at different frequencies of occurrence. The introduced model is tested at moderate and high risk levels controlled in its practical limits through the use of Safety Integrity Functions (SIF). Obtained results show how this fuzzy-LOPA achieves better results to maintain the Safety Integrity Level (SIL) rating to acceptable limits.     

Development of generic bow-tie diagrams of accidental scenarios triggered by flooding of industrial facilities (Natech)

Interactions between natural events and industrial installations may lead to dangerous phenomena. According to bibliographical research, the industrial sector is often unprepared for these joint natural and technological or Natech events mainly because of the lack of guidelines on how to apply Natech regulations and the lack of information on the dynamics of Natechs. In order to fill the gaps and provide guidance on Natech risk assessment to operators, a systematic risk analysis methodology was developed and resulted firstly in proposing general reference bow-ties that reconfigure accidental scenarios triggered by flood events. The validation of these scenarios was made in the surface treatment sector. Building on these bow-ties, the risk analysis methodology will be completed and a checklist simple to use, along with a list proposing preventive and protective measures, to be used by operators in order to decrease the vulnerability of their industrial facilities to technological accidents triggered by floods will be developed in future work.     

Fuzzy risk modeling of process operations in the oil and gas refineries

Operating several assets has resulted in more complexity and so occurrence of some major accidents in the refining industries. The process operations risk factors including failure frequency and the consequence components like employees' safety and environment impacts, operation downtime, direct and indirect cost of operations and maintenance, and mean time to repair should be considered in the analysis of these major accidents in any refinery. Considering all of these factors, the risk based maintenance (RBM) as a proper risk assessment methodology minimizes the risk resulting from asset failures. But, one of the main engineering problems in risk modeling of the complex industries like refineries is uncertainty due to the lack of information. This paper proposes a model for the risk of the process operations in the oil and gas refineries. The fuzzy logic system (FLS) was proposed for risk modeling. The merit of using fuzzy model is to overcome the uncertainty of the RBM components. This approach also can be accounted as a benchmark for future failures. A unified risk number would be obtained to show how the criticality of units is. The case study of a gas plant in an oil refinery is performed to illustrate the application of the proposed model and a comparison between the results of both traditional RBM and fuzzy method is made.For the case study, 26 asset failures were identified. The fuzzy risk results show that 3 failures have semi-critical level and other 23 failures are non-critical. In both traditional and fuzzy RBM methods, some condenser failures had the highest risk number and some pumps were prioritized to have the lowest risk level. The unit with unified risk number less than 40 is in the non-critical conditions. Proposed methodology is also applicable to other industries dealing with process operations risks.     

模糊概率事件的故障树分析

许多职业事故的基本致因事件多属于模糊事件,其概率很难确定。本文以煤矿典型危害——内因火灾为例,探讨了模糊概率下的故障树分析问题。煤矿内因火灾故障树虽具有确定的结构形式,其基本致因事件的概率却无法统计。经过长期的生产实践,煤矿中一大批防火专家可以用自然语言较准确地描述基本事件发生的可能性,这就为故障树分析提供了有效信息。文中以模糊数学为基础,引入Delphi方法,征集并整理了25位专家对龙凤矿内因火灾致因的意见,确定了基本事件的模糊概率及其临界重要度排序,提出了行之有效的防治内因火灾措施。     

Pushing and pulling: an assessment tool for occupational health and safety practitioners

A tool has been developed for supporting practitioners when assessing manual pushing and pulling operations based on an initiative by two global companies in the manufacturing industry. The aim of the tool is to support occupational health and safety practitioners in risk assessment and risk management of pushing and pulling operations in the manufacturing and logistics industries. The tool is based on a nine-multiplier equation that includes a wide range of factors affecting an operator’s health risk and capacity in pushing and pulling. These multipliers are based on psychophysical, physiological and biomechanical studies in combination with judgments from an expert group consisting of senior researchers and ergonomists. In order to consider usability, more than 50 occupational health and safety practitioners (e.g., ergonomists, managers, safety representatives and production personnel) participated in the development of the tool. An evaluation by 22 ergonomists supports that the push/pull tool is user friendly in general.     

Risk assessment tools incorporating human error probabilities in the Japanese small-sized establishment

Although it has been estimated that as many as 80% of all occupational accidents have human errors as a cause, no risk assessment tools incorporating human-related elements have been developed for small companies. Human error probability (HEP) and human error analysis (HEA) have been used for large-scale, safety-critical industries for last three decades, but these tools are not suitable for smaller, more general industries that comprise the majority of accident settings.Here, we describe and verify a risk assessment tool that includes human-related elements for small companies. The tool expands on traditional risk assessment methods, such as matrix, risk graph and numerical scoring method, by adding human-related elements. The tool is easy-to-use in occupational environments, and includes assessments of human behavior and potentially outdated machinery at work place.     

Road accidents,an occupational risk

Road accidents sustained at work represent between 20% and 40% of work fatalities in most industrialised countries, yet few data on occupational road accident risk factors have been published. A case control study was performed to assess the role of work-related risk factors in the occurrence of occupational road accidents. A preliminary qualitative study was carried out to identify possible occupational factors in occupational road accidents, and to draw up the case control study. Cases were recruited from the Rhône road trauma registry (France), controls from voting lists. A telephone interview was performed. Exposure to road risk was measured as a percentage of work time. One hundred and forty-six cases and 440 matched controls were interviewed. Accident risk was found to increase with exposure. Driving was associated with more difficult working conditions than found in jobs not involving driving. These difficulties, however, were not systematically associated with increased occupational road accident risk. Among factors which still emerge after adjustment for road risk exposure, there are scheduling issues (inflexible schedule organisation, lack of consecutive rest-days, lack of flexibility in performing the work), difficulties of communication with superiors, low seniority in the activity, low educational level and physical constraints at work. This study highlights some possible occupational road accident risk factors. Given the chosen case/control methodology, the findings may be considered as advancing our knowledge of the subject, but need confirmation by further studies.