Showing 9 results for Hazard
A. Fazlollah, I. Mohammadfam, M. J. Hadgiparvaneh, M. Omidvari,
Volume 4, Issue 1 (5-2014)
Abstract
Introduction: Nowadays, using multi attribute decision making (MADM) techniques in HSE hazard rating have been widely increased. On the other hand, Analytical Network process (ANP) methods has a high flexibility and accuracy in decision ranking. Therefore, the combination of the two mentioned approaches can provide a more precise prioritization for HSE hazards. Using ANP techniques, in this research a method for accurate rating of HSE hazards in the construction procedure of combined cycle power plant was presented.
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Material and Method: In this study, first, the overall structure and components of ANP method were identified and the connections between its components were determined. Then, the determined structure and components were modeled, using super decision software. In the next stage, pair companions were performed between an criteria and sub-criteria with respect to HSE experts opinions, Finally, selected HSE hazards were prioritized and compared according to the presented ANP method and the common available method.
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Result: According to the results, common risk assessment method is not able to prioritized risk accurately. While the current method classified the ten main identified hazards in 4 general categories, the presented method in this study could prioritized then in 7 categories.
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Conclusion: The suggested ANP model could provide a more accurate prioritization for hazards in comparison with current methods because of considering five qualitative indices. This allows an optimal allocation of organizational resources for controlling hazards.
E. Karami, Z. Goodarzi, T. Hosseinzadeh, G.a. Shirali,
Volume 5, Issue 1 (4-2015)
Abstract
Introduction: The weaknesses of traditional hazard analysis methods lead to their inefficiency to utilization for modern socio-technical systems. System Theoretic Process Analysis (STPA), which is in the category of systematic analysis methods, has a powerful logic to identify hazards in such systems,as a suitable alternative method. This study aimed to analyze hazards associated with extinguishing systems of steam unit of a power plant, using STPA method.
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Material and Method: The present research is a qualitative case study. The related hazards were defined using STPA method.Following, the safety control structure diagrams in different parts were plotted and inadequate control measures and its causal factors were identified.
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Result: For steam unit of power plant, the most tragic incidents wererelated to hazards and risks of turbine device (switch the turbine cycle). Then, according to the plotted diagram for structure of safety control extinguishing systems associated with switching the turbine cycle, PLC system was determined as the most important part of the control system and operator was identified as the strategic and effective part of a control system. Following, more than 54 causal factors were identified, considering the relevant details about the risks analysis of the turbine.
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Conclusion: Due to its systematic structure,STPA method can be effective for a more complete identification of risks and causal factors which causing hazards in the emergency extinguishing systems. Therefore, development of such tools for those operators involved in safety-critical systems will be useful in terms of safety.
H. Zohdirad , T. Ebadi, S. Givehchi,
Volume 6, Issue 1 (4-2016)
Abstract
Introduction: Leakage from process equipment and the entrance of flammable fluids to surrounding atmosphere may cause flammable gas cloud. The coincidence of flammable gas cloud with ignition source could make flash fire or vapor cloud explosion that cause injury and fatality. The concept of reduction of confluence of flammable gas cloud and potential sources of ignition is known as hazardous area classification. Several standards have provided methods regarding hazardous area classification; however, of the disadvantages of them are lack of an accurate determination of hazardous areas due to potential leakage sources which is because of low flexibility in process condition variation and equipment layout and also not considering effect of weather conditions and cumulative effects of release sources.
Method: In this paper, risk-based hazardous area classification is optimized using parameters such as the number of influencing release sources and weather condition probabilities. In this method, the determining factor of hazardous area boundary is the probability of acceptable ignition for every specific location. This probability is calculated using quantitative risk assessment with PHAST RISK software version 6.7 on the gas boosting unit of a gas refinery as a case study.
Result: The results of this method showed the full dependency of hazardous area boundary to cumulative effects of potential sources of release and the prevailing wind direction and it also demonstrated that the suggested optimized method can consider wind direction probabilities and cumulative effects of potential sources of release in risk-based hazardous area classification calculation.
Conclusion: Comparing the results of this method with the usual method determines that this method has some advantages such as considering all sources of release and cumulative sources of release and considering wind direction probabilities in determining boundary of zone 2 which makes the hazardous area classification very precise and flexible.
Ali Tavakoli Kashani, Mohammad Mehdi Besharati, Amin Radmard,
Volume 8, Issue 3 (9-2018)
Abstract
Introduction: Examining the effect of bus drivers’ demographic characteristics as well as workplace conditions on their traffic behavior and performance is important not only for drivers’ health and safety, but also for the safety of bus passengers. The aim of this study was to investigate the relationship between demographic variables and work shift schedule on the behaviors pertaining to “hazard monitoring”, “relax driving”, “fatigue proneness”, and “thrill seeking” among intercity bus drivers.
Material and Method: In this cross-sectional study a sample of 321 bus drivers were randomly selected from Tehran intercity bus terminals. The BDRI questionnaire was used to collect data. The Pearson’s correlation coefficient and the ANOVA and Tukey’s HSD tests were used to analyze the data.
Result: In general, the findings showed that age, driving experience and rest time period positively correlate to lower fatigue, lower thrill seeking and more relaxed driving. Drivers with higher vehicle age were found to perform worse than others in hazard monitoring and to be more prone to the stress and fatigue. Also, fatigue and relaxed driving were significantly related to the marital status and cigarette usage. In addition, drivers who were college graduate or above were found to perform worse than other drivers considering all of the four factors. Furthermore, those who drive in mountainous routes were found to perform worse than other drivers in hazard monitoring and fatigue proneness.
Conclusion: Since the age and driving experience were found to influence fatigue proneness, hazard monitoring and relaxed driving, thus, setting up specific training courses for different driver age groups aiming to enhance their awareness concerning on managing these factors might help drivers improve their performance in these factors. Furthermore, regarding the effect of rest period and route type on the drivers’ fatigue and hazard monitoring ability, appropriate regulations are needed to mitigate the effect of these factors on the performance of drivers.
Mehran Amiri, Abdollah Ardeshir, Ali Abbasi,
Volume 8, Issue 4 (12-2018)
Abstract
Introduction: Safety at workplaces is an important issue, and lack of effective and efficient safety management methods based on scientific studies could cost the construction industry. An effective accident investigation and root causes analysis could prevent the occurrence of incidents at minimum cost and time.
Material and Method: First, major accidents in road construction projects were identified by interview and literature reviewing techniques. Then, fault tree was drawn for each main risks. In the next step, in order to calculate occurrence probability and severity of each accident type, a questionnaire was designed and distributed among the participants. Fuzzy logic was employed in calculations, due to the existence of uncertainty in linguistic variables. Fuzzy Fault Tree Analysis (FFTA) was used for calculating the occurrence probability, and importance of each criterion was determined using Fuzzy Analytical Hierarchical Process (FAHP) to calculate the severity of each accident. Finally, risk factors for each accident type was calculated and the risks were ranked accordingly.
Result: Accidents related to crusher and asphalt plant, traffic accidents, heat exhaustion and lack of hygiene and hit by machinery were identified as the most important risks among the eleven investigated accident types.
Conclusion: The findings in this research and also implementing effective safety management techniques, could be helpful on reduction of the probability of accidents root causes and to mitigate related risks.
Ameneh Fayazi, Mostafa Pouyakian, Mohammad Javad Jafari, Soheila Khodakarim,
Volume 9, Issue 1 (4-2019)
Abstract
Introduction: Changing the national System of Classification and Labelling of Chemicals to Globally Harmonized System of Classification and Labelling of Chemicals (GHS) is beneficial for all the industries of the countries, their workers and the general public. Increasing the awareness of chemical hazards, improving the safety uses, reducing chemical accidents, and providing better conditions for emergency response in the event of chemical accidents, are some of the most important benefits of the GHS. Present study aimed to develop a tool for assessing the awareness level of chemical related personnel using the GHS and current status.
Material and Methods: By reviewing the literatures, the GHS Guide, available sources and consultation with experts, two questionnaires were developed to assess the level of awareness of chemical related personnel and current statue. The two designed questionnaires included personal information, multiple choice questions and questions related to safety signs. The face and content validity was conducted using the experts’ panel assessment. The face validity, content validity ratio (CVR) and content validity index (CVI) were all calculated for each question.
Results: Content Validity Ratios (CVR) and Content Validity Index (CVI) were calculated for each question. The general clarity, general fit and general simplicity of the awareness questionnaire (questionnaire number 1) were obtained 0.87, 0.91 and 0.77, respectively. The mean content validity index and the mean content validity ratio were obtained 0.85, 0.85, respectively. The overall clarity, overall fit, and the general simplicity of the current status questionnaire (questionnaire number 2) was 0.92, 0.89 and 0.93, respectively. The mean content validity index and mean content validity ratio were obtained 0.92 and 0.81, respectively.
Conclusion: The two questionnaires used to assess the awareness level of chemical related personnel and current statue of GHS, were identified as valid instruments and therefore is recommended as a valid tool for future studies.
Rostam Esmaeili, Ahmad Ali Babaei, Ghazaleh Monazami Tehrani,
Volume 11, Issue 2 (6-2021)
Abstract
Introduction: Each country needs to preserve its human capital through preventing accidents for its development. Therefore, this study is carried out to study the relationship between safety investments and safety performance indices considering the interactive effect of the project hazard level in construction industry.
Material and Methods: This study was conducted using multiple case studies in 5 major construction worksites, in Tehran, in 2019. Data was collected using questionnaire, checklists and interview as well as evaluating the safety documents. The data analysis in this study was carried out using SPSS 18.
Results: There was a strong inverse correlation between safety investments (total safety investment, basic safety investment, and voluntary safety investment) and accident frequency rate (AFR) (r=-0.936, P-value<0.05), and there was a direct strong correlation between safety investment and safety performance (P-value<0.05, r=0.939). Also, the effect of various safety investments on safety performance indices under various project conditions (project hazard levels) was not the same; when the project hazard level was high, the effect of safety investments on safety performance was higher.
Conclusion: Increasing safety investment improves safety performance through decreasing the accidents. Also, investment in both safety components (basic safety investment and voluntary safety investment) might improve safety performance. The results of the current study can be used as a basis by the contractors and construction companies to invest in safety and to determine proper budget for managing safety of construction projects.
Somayeh Moradhaseli, Ali Asghar Mirakzadeh, Farahnaz Rostami,
Volume 11, Issue 3 (9-2021)
Abstract
Introduction: The development and implementation of effective safety educational program for minimizing hazards in a farm, is the most important activity that can be done to improve safety level there. This program, however, requires to needs assessment process. So, the present study was designed to analyze of the educational needs of farmers in the field of agricultural occupational health.
Material and Methods: This quantitative study was conducted with a survey method. Statistical population consisted of farmers in Mahidasht County, Kermanshah Province, Iran (N =213), where 140 farmers was selected as sample by simple random sampling method and base on Krejcie & Morgan table. Research instrument was research made questionnaire that its validity confirmed by a panel of experts and the reliability was confirmed through a pilot study and calculation of Cronbach’s alpha coefficient. SPSS/16 software was used for data analysis.
Results: Findings showed that educations in the field of occupational health were done neither sufficient nor according to the principles. Educational needs identified in the area included exposure to noise, exposure to dust, ergonomic issues, compliance with hygiene and protection principles in spraying, individual protection in working with tractors and other machinery.
Conclusion: Dangers of farming in one hand and the lack of appropriate education and the farmers’ dissatisfaction in the other hand, has highlighted the necessity of implementing correct eductional programs according to needs assessment principles in Mahidasht County. In this regard, considering the knowledge and occupational health behaviors of the studied farmers, they need to receive education in most areas of health, among which, environmental hazards (sun and noise, dust on farms), ergonomic issues, proper and safe use of chemical input and adherence to safety principles in working with agricultural machinery are considered priorities.
Ali Fardi, Mohammad Karkhaneh, Hamidreza Heidari, Abolfazl Mohammadbeigi, Ahmad Soltanzadeh,
Volume 12, Issue 2 (6-2022)
Abstract
Introduction: Methane is one of the most widely used gases in industries with a high flammability potential. This study aimed to evaluate the efficiency of ventilation systems installed on methane valve pits based on hazardous areas classification.
Material and Methods: This study was implemented in a steel industry in Qom Province in 2019. The tools used in this study were a DELTA OHM pitot tube (DO-2003) to measure wind speed, EPA Protocol for equipment leak emission estimates (U.S. Environmental Protection Agency) and IEC-60079-10 for evaluating the safety of ventilation of methane valve pits.
Results: The methane LELm was about 0.0334 kg/m3, and the volume of the release area was approximately VZ = 0.053 m3. The expected leak emissions were within the Vz < 0.1 m3 range. The ventilation system embedded on methane distribution pipelines was not effective for openings with diameters of more than 0.3 mm and the volume of gas inside the valve pits would quickly exceed high ventilation border which might lead to a dangerous accumulation of gas in the valve pits.
Conclusion: Given that a very small opening or leak in gas transmission valves may lead to the formation of an explosive atmosphere, it is essential to monitor methane before entering the valve pit area and performing any operations on valve pits.
