A fuzzy model for assessing risk of occupational safety in the processing industry

Managing occupational safety in any kind of industry, especially in processing, is very important and complex. This paper develops a new method for occupational risk assessment in the presence of uncertainties. Uncertain values of hazardous factors and consequence frequencies are described with linguistic expressions defined by a safety management team. They are modeled with fuzzy sets. Consequence severities depend on current hazardous factors, and their values are calculated with the proposed procedure. The proposed model is tested with real-life data from fruit processing firms in Central Serbia.     

Biomechanical assessment of three rebar tying techniques.

The National Institute for Occupational Safety and Health (NIOSH) conducted a study of ironworkers to evaluate their risk for developing back and hand injuries from hand-tying reinforcing steel bar and to investigate whether power tying tools can be an effective intervention for the prevention of work-related musculoskeletal disorders. A field investigation of biomechanical loading when using 3 techniques to tie together rebar was conducted. Researchers measured employees' wrist and forearm movement with goniometers and videotaped and analyzed trunk postures. Manually tying rebar at ground level involved sustained deep trunk bending and rapid, repetitive, and forceful hand-wrist and forearm movements. Using a power tier significantly reduced the hand-wrist and forearm movements and allowed the ironworkers to use one free hand to support their trunk posture while tying. Adding an extension handle to the power tier allowed the ironworkers to tie rebar while standing erect, minimizing sustained trunk flexion.     

A comparison of web-based and telephone surveys for assessing traffic safety concerns, beliefs, and behaviors

Introduction

The purpose of this investigation was to compare the results of a web-based and a telephone interview survey measuring driver concerns about a variety of traffic safety issues, their beliefs, and specific driving behaviors.

Method

State-wide, annual random digit-dial telephone surveys and web-based surveys were conducted in Maryland. A total of 1,700 drivers were surveyed by telephone and 6,806 took a web survey.

Results

Telephone respondents were more likely to be female and older. Web respondents were more likely to be white and not Latino/Hispanic. After controlling for demographic differences, telephone survey respondents were more likely to be concerned about traffic safety. They were more likely to believe that sobriety checkpoints reduce drunk driving (OR = 2.18, 95% CI 1.94, 2.45), they would be ticketed for not wearing a seat belt (OR = 1.26, 95% CI 1.12, 1.43), and they would be stopped by the police if they drove after drinking too much (OR = 1.17, 95% CI 1.03, 1.32). They were less likely to report a variety of risky behaviors including using a cell phone while driving (OR = .54, 95% CI .48, .61) and driving 10+ mph over the speed limit (OR = .81, 95% CI .72, .91), but were more likely to report having been ticketed for a moving violation in the last month (OR = 2.22, 95% CI 1.70, 2.90). Suggestions are offered for overcoming potential sources of sampling bias.

Impact on Industry

Web-based surveys produce substantially different results than random-digit-dial telephone surveys, when used for public assessments of traffic safety concerns and behaviors.     

A methodology for assessing blast protection in explosive ordnance disposal bomb suits.

To reduce human casualties associated with explosive ordnance disposal, a wide range of protective wear has been designed to shield against the blast effects of improvised explosive devices and munitions. In this study, 4 commercially available bomb suits, representing a range of materials and armor masses, were evaluated against 0.227 and 0.567 kg of spherical C-4 explosives to determine the level of protection offered to the head, neck, and thorax. A Hybrid III dummy, an instrumented human surrogate [1], was tested with and without protection from the 4 commercially available bomb suits. 20 tests with the dummy torso mounted to simulate a kneeling position were performed to confirm repeatability and robustness of the dummies, as well as to evaluate the 4 suits. Correlations between injury risk assessments based on past human or animal injury model data and various parameters such as bomb suit mass, projected area, and dummy coverage area were drawn.     

系统安全评价方法对比研究

安全评价是衡量风险,实现安全生产的重要途径。为了不同的评价目标开发出来的各种安全评价方法都有其针对性和局限性。认清这些方法的优点和缺点有助于系统地运用安全评价方法衡境目标的风险。安全评价软件有助于弥补安全评价方法的不足,并提高安全评价的效率和可靠性。     

Refinery firefighters: assessing fitness for duty.

Firefighting is a hazardous and physically demanding activity. The demanding nature of the tasks involved in firefighting requires a high level of fitness both for the safety of the firefighting personnel as well as for the adequate performance of their tasks. Here, the characteristics (body weight, lung function, etc.) of a small group of refinery firefighters were investigated using exploratory factor analysis and discriminant analysis. The results indicated that there is a group of factors that characterize those individuals meeting minimum fitness requirements as described previously in the literature. The factors that were identified included those related to anthropometry (such as body composition and weight) and those related to physical capabilities (such as push-ups). Since these data are collected relatively easily in most occupational settings, they may offer an efficient surrogate method to determine fitness for duty among firefighters.     

A methodology for assessing underground coal mines for high safety-related risk

In 2008 the authors developed a methodology for assessing underground coal mines for high risk for major-hazard events. It focused on major hazard-related violations of safety standards associated with high-risk conditions. Later using the same stratified pilot sample of 31 mines, injury measures and MSHA citation data were combined into a Safe Performance Index (SPI). Using 2009 data, the database was expanded to 107 mines, which is a 30% sampling of all underground coal mines. The SPI was used to assess the relative safety-related risk of mines, including by mine-size category. The methodology can be used to assist companies, the Mine Safety and Health Administration, or state agencies in targeting mines with high risk for serious injuries and elevated citations for remediation of their violation and/or injury experience.     

Estimating rate constants of contaminant removal in constructed wetlands treating winery effluent: A comparison of three different methods

In this paper we investigated the use of three different methods for determining the rate constants for degradation of winery effluent within a sub-surface flow constructed wetland (CW). These methods comprised of using a dispersed plug flow (the Peclet) equation; a tanks-in-series (TIS) equation; and analysing the residence time distribution (RTD) directly. The last of these is described by the convolution integral (CI). We demonstrated self-similarity of the RTDs, which meant that the system's hydraulics were similar throughout the CW. We therefore extrapolated the RTD data to develop a more complete understanding of the hydraulic properties of the CW and examine how they affected the kinetics of degradation. We found that whilst both the Peclet and the TIS equation were able to predict concentration within the CW, this required the optimisation of more than one variable at the same time rendering a result that was more of a modelling exercise than a useful design tool. The CI method could be applied to predict system parameters effectively. We used it to measure rate constants of removal for both ethanol and potassium (key species for tracking the degradation/treatment of the effluent). Acetic acid, however, did not degrade implying that the CW operated aerobically. The concentration of sodium increased very slightly, indicating that it is not bioremediated/removed and that there are some minor evapotranspirative effects. The rate constant found for the biodegradation of COD was found to have significantly more uncertainty associated with it than the measurement of the rate of degradation individual components and we therefore posit that it is better to describe the processes of degradation by tracking individual components rather than lumped parameters.     

Classification of errors contributing to rail incidents and accidents: A comparison of two human error identification techniques

Identifying the errors that frequently result in the occurrence of rail incidents and accidents can lead to the development of appropriate prevention and/or mitigation strategies. Nineteen rail safety investigation reports were reviewed and two error identification tools, the Human factors analysis and classification system (HFACS) and the Technique for the retrospective and predictive analysis of cognitive errors (TRACEr-rail version), used as the means of identifying and classifying train driver errors associated with rail accidents/incidents in Australia. We aimed to identify the similarities and differences between the techniques in their capacity to identify and classify errors and also to determine how consistently the tools are applied. The HFACS analysis indicated that slips of attention (i.e. ‘skilled based errors’) were the most common ‘unsafe acts’ committed by drivers. The TRACEr-rail analysis indicated that most ‘train driving errors’ were ‘violations’ while most ‘train stopping errors’ were ‘errors of perception’. Both tools identified the underlying factors with the largest impact on driver error to be decreased alertness and incorrect driver expectations/assumptions about upcoming information. Overall, both tools proved useful in categorising driver errors from existing investigation reports, however, each tool appeared to neglect some important and different factors associated with error occurrence. Both tools were found to possess only moderate inter-rater reliability. It is thus recommended that the tools be modified, or a new tool be developed, for complete and consistent error classification.     

A risk-estimation methodological framework using quantitative assessment techniques and real accidents’ data: Application in an aluminum extrusion industry

The risk estimation presumably is the most crucial part of the entire procedure of assessing hazards/unsafe situations in the work, and especially in the industries’ and constructions’ worksites, where the working conditions are unstable. We can consider the risk as a quantity, which can be estimated and expressed by a mathematical relation, under the help of real accidents’ data. The aim of this work is quadruplicate: (a) the development, elaboration and explanation of two new quantitative risk-assessment techniques, (b) the improvement of specific points of other scientific works, as far as concerns quantitative risk estimation, (c) the application of these techniques on an industrial productive procedure (as a case study) and (d) the comparison of their outcome risk-estimation results. Particularly, we develop and analyze the theoretical background of the two techniques, which we call as “proportional technique” and “decision matrix technique”, and apply them on an aluminum extrusion industry's worksite, which is situated in Greece, by using real data of potential sources of hazards, recorded by safety managers, during the 5.5-year time period of 1999–2004. Comparing the results of the two quantitative risk-assessment techniques, we infer that they are compatible. Therefore, the most important hazard source in the aluminum industry is the “squeezing and hits by dropping objects (transported by derricks)”, and imposes that immediate suppressive measures must be taken place to abolish the danger source.     

民航3类安全信息的TEM分布特征比较研究

通过对自愿报告、强制报告和正常运行安全监测(NOSS)数据的威胁与差错管理(TEM)分析,获得了3类安全信息的威胁、差错和意外状态的分布特征.对比研究发现,强制报告中空中威胁、环境威胁的分布比例(55.46%; 16.8%)明显高于自愿报告(32.42%; 10.35%)和NOSS(19.26%; 11.7%),说明强制报告信息侧重外部威胁与他人错误.自愿报告中"内部威胁-其他管制员"的比例(20.85%)显著高于NOSS(6.91%)和强制报告数据(4.20%),说明自愿报告可有效识别内部协作威胁和认知差错; NOSS对易识别、独立责任的"程序差错-文件"检出率(25%)显著高于自愿报告(2.81%)和强制报告(0%),证实了NOSS信息的客观性,但NOSS对低频度、高危害类差错的检出率显著偏低,说明小样本NOSS信息存在波动性.     

A fuzzy risk assessment approach for occupational hazards in the construction industry

The techniques in the construction industry have been improved due to the rapid development of science and technology. However, the constructional hazards are not decreased as expected. To reduce or prevent occupational hazards in the construction industry, a fuzzy risk assessment method was proposed to provide a prevention and improvement technique against occupational hazards. This method used two-stage quality function deployment (QFD) tables to represent the relationships among construction items, hazard types and hazard causes. A fuzzy analytic network process (ANP) method was developed to identify important hazard types and hazard causes. Failure modes and effect analysis (FMEA) was performed to assess the risk value of hazard causes based on the fuzzy inference approach. The proposed method was applied to a telecom engineering company in southern Taiwan. The performance evaluation result indicated that this method can provide satisfactory risk assessment values of hazard causes and relevant improvement strategies.     

A medium scale test method for assessing the fire hazard of flammable solid materials

The medium scale test method currently operated by the Health and Safety Executive (HSE) as a means of assessing the fire hazard of flammable solids is described. The technique has been applied to a range of materials and the results, although specific to the apparatus, have proved useful in ranking relative fire performance     

Procedure for assessing hardware safety integrity in legacy systems

Functional safety is related to the safety functions of a safety-related system that uses electrical/electronic/programmable (E/E/PE) devices such as sensors, logic solvers, and final elements. A legacy system is a safety-related system which offers safety functions but which was not designed to comply with the IEC 61508 standard. This paper presents a procedure for assessing the hardware safety integrity of a legacy system so as to confirm its functional safety. The procedure defines the systematic relationship between the safety function and hardware system using a function-structure map (FSM) and assesses the hardware safety integrity centered on the safety function. The proposed procedure is applied to a boiler control system of a fossil-fuel power plant.     

A reliability data bank for the natural gas distribution industry

This study is an extended and updated version of those already reported. It illustrates the results obtained from ordinary maintenance operations on six large sets of urban mains, with a view to optimizing the establishment of a reliability data bank. The study illustrates the extreme individuality of gas distribution plants and the need for a sector data bank.     

A comparison of injury criteria used in evaluating seats for whiplash protection

A protocol has been proposed for testing seats for whiplash protection, however injury criteria have not yet been chosen. Assuming that whiplash symptoms arise from non-physiological motions of vertebral segments, we determined the ability of proposed criteria to predict peak individual vertebral displacements. Twenty-eight volunteers were subjected to rear impacts while seated in a car seat with head restraint, mounted onto a sled. Accelerometers were used to record head and torso accelerations. The volunteer data was used as a basis for testing post-mortem human specimens (PMHS). The seat was replaced by a platform onto which was mounted each of 11 cervico-thoracic spines. An instrumented headform was mounted to the upper end of the spine. The head restraint, head-to-restraint geometry, sled, and impact pulse remained the same. Head and T1 accelerations were measured and individual vertebral sagittal (XZ) plane rotations and translations were obtained from high speed video. Proposed injury criteria (NIC, Nkm, Nte, Nd) were tested for their ability to predict average, total, and peak intervertebral displacements. PMHS specimens had chest and head X (horizontal) and Z (vertical) linear accelerations similar to volunteers whose heads hit the head restraint. The best predictors were: Nd shear and peak intervertebral posterior translation (r(2) = 0.80), Nd extension and peak extension angle (r(2) = 0.70), and Nd distraction and peak distraction (r(2) = 0.51). Therefore consideration should be given to a displacement based injury criteria such as Nd in assessment of whiplash protection devices.     

A method for assessing health and safety management systems from the resilience engineering perspective

This article introduces a method for assessing health and safety management systems (MAHS) that has two innovative characteristics: (a) it brings together the three main auditing approaches to health and safety (HS) – the structural approach (which assesses the system prescribed), the operational approach (which assesses what is really happening on the shop-floor) and the performance approach (which assesses the results of performance indicators); (b) it emphasizes the resilience engineering perspective on HS, which takes into consideration four major principles (flexibility, learning, awareness, and top management commitment). Such principles underlie seven major assessment criteria, which in turn are divided into items (e.g. hazard identification from a resilience perspective is an item that belongs to the criteria of production processes). The items are sub-divided into statements, which are the requirements that should be assessed based on interviews, analysis of documents and direct observations. Within the 112 requirements proposed, 38 of them have clear links with at least one out of the four resilience engineering principles adopted. The remaining requirements are based on traditional assumptions underlying the so-called best practices of HS management. The results of the assessment for each item are expressed by a score on a scale of compliance with the established requirements, ranging from 0% to 100%. The specific score within that scale is obtained from tables used to assess applications for the Brazilian national quality award. The MAHS was tested in a case study that was carried out in a factory that manufactures automobile exhaust systems, located in Brazil.     

A comprehensive framework for assessing and selecting appropriate scaffolding based on analytic hierarchy process

Problem: Bamboo scaffolding has been widely used in South China, Hong Kong, and Southeast Asia for many years. Bamboo scaffolding is more economical, but its safety record is relatively poor. Conversely, metal scaffolding is more expensive, but its use in these regions has increased in recent years because it is relatively safe. The assessment and selection of the most appropriate type of scaffolding for a particular construction project is always a concern for project managers. Method: This paper suggests a comprehensive assessment framework that enables project managers to take a number of major quantitative and qualitative factors into consideration when making scaffolding decisions. This framework is based on the Analytic Hierarchy Process methodology and a survey among project managers in Hong Kong. Results: The research reveals that the overall performance of metal scaffolding is believed to be better than bamboo scaffolding. A sensitivity analysis has also been conducted to investigate the impact of various factors on the final decisions. Impact on Industry: The proposed assessment framework can be used as a supporting tool for project managers in the selection of scaffolding for their projects.