Risk assessment of oxygen plant by HAZOP and What if in Besat hospital in Sanandaj

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International Research Journal of Applied and Basic Sciences 2016 Available online at www.irjabs.

1 International Research Journal of Applied and Basic Sciences 2016 Available online at ISSN X / Vol, 10 (8): Science Explorer Publications Risk assessment of oxygen plant by HAZOP and What if in Besat hospital in Sanandaj Mostafa Mirzaei Aliabadi, Iraj Mohammadfam, Foad saiedi * Department of Occupational Health and Safety, Faculty of Health,Hamadan University of Medical Sciences, Iran *Corresponding Author Foad.saidi63@gmail.com ABSTRACT: Background and Objectives: Many events daily happen in workplaces that resulted in the death and injury. Such incidents are often caused because of the failure to identify potential hazards, assess and provide control solutions. Therefore, many events can be prevented by identifying potential hazards, assessing and providing control solutions. The aim of this study is the risk assessment of oxygen plant machines by HAZOP and What if methods in Sanandaj Besat hospital and comparison of these methods with each other and selection of superior technique. Methodology: In this study, the risks involved in oxygen generating machine were identified by using HAZOP method in 9 nodes and by what if method in 12 nodes. With regard to the protective system, number of risk was determined and number of secondary risk was obtained by providing control solutions. At the end, the data collected was analyzed by the two mentioned techniques. Findings: The results showed that 177 risks were in 12 nodes related to what if method (more than 80% risks) among the 220 risks identified that 9 risks (5%) tolerable, 123 risks (69.4%) with unsuitable conditions and 45 risks (25.4%) were intolerable, and 26.4% of risk control solution with high costs, 41.4% of risk control solution with average costs and 32.2% of risk control solution were with low costs. 43 risks were in 9 nodes related to HAZOP method (less than 20% risks) that 2 risks (4.6%) tolerable, 31 risks (72%) with unsuitable conditions and 10 risks (23.2%) were intolerable, and 39.2% of risk control solution with high costs, 40.5% of risk control solution with average costs and 20.3% of risk control solution were with low costs. Conclusion: Although the number of potential risks identified in what if method was more than the HAZOP method and more percentage of intolerable risks was controlled by what if method to the HAZOP method with low cost, and complexity, time and cost required for assessment with HAZOP method were more than the what if method, it is suggested that at least several methods to be used to identify risks, because identification and assessment of risks by a method is not sufficient. Keywords: Risk assessment, what if, HAZOP, Operability Oxygen plant INTRODUCTION Many events occur daily in the workplace that lead to injury and death, Identifying and assessing risks is one of the ways to prevent workplace events (1). Such as important events that throughout history have occurred many events throughout history the world such as Chernobyl disaster in 1986, Three Mile Island accident in 1979 and Flixborough explosion in 1974(2). event Mid-morning on 25 August 2012, a sudden, unanticipated and complete central oxygen pipeline failure occurred throughout Tygerberg Hospital, which caused an explosion and the subsequent failure of the main oxygen valve. This happened while I was on duty in the surgical intensive care unit (ICU), with two patients on full ventilation and four patients breathing spontaneously on 40% oxygen face masks(3). Heinrich was the result of an accident That 88% were caused by unsafe acts, 10% by unsafe conditions, and 2% by unpreventable causes(4). Mr. Graham's research result in the field of value of safety programs, Health, and environment on workplace and workforce was in such a way that prioritizing the safety programs in main policy of the organization increases productivity and enhances employees morale and their sense of responsibility(5). Mr. Miller et al in 1995 carried out studies on occupational events and economic costs resulting from incidents and came to the conclusion that accident prevention is one of the effective factors in reducing costs and increasing productivity (6, 7). In order to prevent or minimize events, enormous efforts to increase the level of safety, risk management and emergency preparedness are necessary. This realization and increased awareness to the issue leads to the development of new methods of risk assessment and safety evaluation in the process industries (8). Risk assessment is the

2 identification of risks, calculation risk number, and provision of appropriate control measures to control the risks available in a process or a job. HAZOP study is used to identify risks in process industries and to identify operational problems which, although not dangerous, but it can reduce the productivity of an industry. When deviations from process design conditions occur, operational problems and events can happen. Study method of HAZOP is the use of clue words to help the analysis team regarding the causes and consequences of deviations. These clue words are used in a specific sectors and points of a process or combined with specific parameters of the process to identify potential deviations of the desired operation. A HAZOP study consists of three parts: process definition, conducting study and documentation of the results. HAZOP study is done on certain parts of the process which is called (Node) study that focuses on parts of the process or stages of operation (9). HAZOP method is used to identify risks in industries. Like the HAZOP method, What if method is designed for the assessment of process deviations from limits and used for the identification of potential risks and therefore, the information needed for the implementation of both methods is same (10). One of the centers that provide services in every city are hospitals. In fact, hospitals are an important part that vital health care services are done in them. One of the most important wards in hospitals is oxygen plant ward that provides required oxygen for patients in wards, particularly special sections (CCU) and operating rooms. Given that oxygen plants have several risks such as ignition and explosion, and these risks can lead to catastrophic and irreparable consequences for the devices, operators, personnel of medical staff and patients which makes it difficult or impossible to serve and treat patients. Thus, maintaining the proper functioning of the devices to supply oxygen needed for remedial wards is essential. According to proactive approach, events should be prevented by identifying and assessing the risks. Therefore, this study aimed at quantitative risk assessment by HAZOP and what if methods in the hospital. Analysis method This descriptive-analytical study was carried out in engineering units, oxygen generating unit of Besat hospital. Task of oxygen generating machine is that it takes air from the surrounding environment, separates oxygen, and generates high doses of oxygen. The study was conducted in two general parts. The first part involves identifying risks on oxygen generating machine using HAZOP and what if methods that collection of information was conducted by using hospital oxygen generating machine instructions, interviews with machine operator and checklists and the second part was on risk assessment of the two mentioned methods by a team of people in the hospital. Identifying and assessing risks in oxygen generating machine for the hospital was conducted by a team of specialists including hospital administration, responsible for establishing, occupational health engineer, responsible for medical equipment and responsible for quality improvement of the hospital. At first, oxygen generating machine was divided to nodes by P & ID; process and equipment of oxygen generating systems for hospitals were detected (information needed for both methods was identical). In the next step, the system risks were identified and assessed by using HAZOP and what if techniques. Then, risk of identified hazards was determined by using the risk matrix and appropriate solutions were provided to control the unacceptable risks. After this, the remaining risks were calculated to determine the effectiveness of the controls used. Finally, two techniques of HAZOP and what if were compared and superior technique was selected. Information needed to start the HAZOP study The following information should be available as a basis for studying HAZOP: Map of plant and equipment Map of process and equipment Process flow diagrams Equipment and piping diagrams Equipment layout diagrams Operating instructions Operating parameters Principles and rules and regulations inside the factory Special specifications of equipment (temperature, pressure and...) HAZOP Methodology System division After getting familiar with process and equipment, the system should be divided into sections. For example, oxygen generating machine in the study was divided to parts such as fan (propeller), belts and alternator, air, oil separator chamber, radiator, absorption dryers, air storage tank and oxygen and etc. Selecting the study node: Node is a special place in the process where operating parameters will change. 1098

3 Identifying deviations using clues Primary keywords: Temperature, flow, viscosity, pressure, acidity and... Secondary keywords: The keywords associated with primary keywords refers to possible deviations. Table 1: Key words Secondary key words Describe deviations None Do not be physical process (for example, there is no flow). more than Physical properties that should be much more relevant. For example, the pressure is too much defined. less than Physical properties that should be much less relevant. For example, the temperature is less than defined. in addition to There are other cases other than those defined. For example, the flow of gas containing liquid droplets. part of Combining different than it should be fine. For example, part of the composition of particles larger than 200 microns. Contrast Process, the reverse happens defined. For example, the fluid flow is reversed. instead of Sometimes abnormal operation occurs. For example, instead of the low speed increases. Determining the causes In this stage, the causes for creating deviation are reviewed. Several reasons may be detected for a deviation. Often it is advisable to start with the reasons that lead to the worst possible consequence. Checking the consequences The consequences may be both process risks as well as operational problems, such as plant closings or reduced product quality in cases that results of deviation happen. At this stage, the consequences of any cause were investigated regardless of the safety protection. Justification of necessary measures Against the results of credible causes in a negative consequence, it should be decided what measures are necessary? At this stage, the relevant consequences and protections should be considered. If it appears that protective measures are sufficient, then no action is required. Actions are divided into two groups: A- Actions that eliminate the cause B- Actions that eliminate or reduce the consequences [15]. In this study, most of the measures recommended are dedicated to classes with unacceptable moderate-risk. Determining the primary and secondary levels of risk Those risk levels that are checked regardless of (pre implementation) corrective measures proposed are primary risk levels and those risk levels that are checked with regard to (post implementation) corrective measures proposed are called secondary risk levels. In this study, factors of severity of outcomes, probability of outcomes, and probability of detection were used to determine the risk, and amount of control cost is used to prioritize the same risk levels. The control cost is a cost which is necessary for proposed corrective measures. Table 2: severity Severity Description Severity Score Severe / catastrophic Death / loss of full equipment as the need to replace equipment. 5 Serious Disability, deformity and disease that in the long term (over three years) becomes apparent / loss of a 4 major part of equipment as a whole is in need of reconstruction. Average Injury with hospital stay And diseases that short-term (less than three years) becomes apparent / The 3 need major repairs equipment with long lines stop there. Small No injuries or effects hospital stay and minor repairs with a short stop for line 2 Little/ Meager Injuries with outpatient treatment and first aid / Minor repairs without stopping the line. 1 Table 3: probability of occurrence Probability Score Extreme and imminent event (which can happen every day) 5 Common event (which can happen during the week) 4 Probable and average event (which can happen during the month) 3 Low amount of event (which can happen during the years) 2 Impossible and unlikely event (which happens every 10 years) 1 Table 4: The chance discovery Index Description 1 Almost certainly detect the potential risk controls. 2 It is most likely that the potential risk controls be recognized. 3 There is a small chance that risk be recognized. 4 There is a very small chance that the existing controls detect risk. 5 With existing controls are not able to detect risk. 1099

4 Table 5: how to determine risk Level of risk RPN Description of performing control operations Little(down) 1-10 The situation is intolerable. Average The situation is not perfect and in need of revision is prioritized. above Aspect is intolerable and should be the first priority, improvements are necessary The control cost was specified based on criteria of Besat hospital in Sanandaj and assessment group was as follows: Less than or equal to five hundred Tomans: low cost Between five hundred to one million Tomans: average cost More than a million Tomans: high cost What if study method The real name of what if technique is derived from the phrase "If this happens, what consequences will be" and the main purpose of its implementation is to apply the attention and concentration to effects of unwanted events on the system. The basis of this analysis method is based on asking questions with simple words, what if...? And finding their real and accurate answers. If the technique is implemented by people with experience and enough knowledge of the system, it can be a very useful tool in the system safety analysis. Like the HAZOP method, the technique is designed to assess the possible deviations of process from standard limits and therefore, the same information that is required to run HAZOP will be necessary to implement this technique. Findings Analysis of worksheets showed that the total identified risks have been 220 cases that 177 risks were related to what if method with 12 nodes that the total number of tolerable risks was 9 cases, the total number of risks with unsuitable conditions was 123 cases and the total number of intolerable risks was 45 cases. The remaining 43 risks were related to HAZOP method with 9 nodes that the total number of tolerable risks was 2 cases, the total number of risks with unsuitable conditions was 31 cases and the total number of intolerable risks was 10 cases. The highest risk identified in the what if method was related to air compressor node with 42 risks and the highest risk identified in the HAZOP method was related to air input node into the filter with 7 risks. Also, the total percentage of tolerable risks 5%, total percentage of risks with unsuitable conditions 69.4%, total percentage of intolerable risks 25.4% and total percentage of risk control solution with high cost 26.4%, total percentage of risk control solution with average cost 41.4%, and total percentage of risk control solution with low cost was 32.1% in the what if method. The total percentage of tolerable risks 4.6%, total percentage of risks with unsuitable conditions 72%, total percentage of intolerable risks 23.2% and total percentage of risk control solution with high cost 39.2%, total percentage of risk control solution with average cost 40.5%, and total percentage of risk control solution with low cost was 20.3% in the HAZOP method. Table 6: identified risk Oxygen plant Total number of identified risks 220 Number of identified risks by what if 177 Number of identified risks by HAZOP 43 Table 7: results of the evaluation HAZOP and what if Assessment Risk assessment by HAZOP risk assessment by What if Node Number of Node: 9 Number of Node: 12 risks Number of risk Percent Number of risk Percent Total number of identified risk Total number of risk portable Total number of status inadequate risk Total number of intolerable risk Table 8: costs offered by two methods what if and HAZOP Assessment HAZOP what if risks Number of risk Percent Number of risk Percent Total number of risk with high cost Total number of risk with the average cost Total number of risk with the low cost Total

5 Table 9: the approaches taken by the two methods what if and HAZOP Assessment HAZOP what if risks Number of risk Percent Number of risk Percent Percent risk control solution with high costs Percent risk control solution with average costs Percent risk solution control with low cost Total DISCUSSION In order to ensure patient safety during a central oxygen pipeline, a systematic approach is needed to avoid failure and control of such events which strategies of hospital planning and crisis management are necessary (3). In a study conducted by Mr. Iraj Mohammadfam et al. entitled the use of Hazard and Operability Study (HAZOP) technique in the assessment of safety, medical and environmental risks, the technique was considered as one of the most common risks analysis techniques in industries because of high structure design and easy learning (9). Mr. Javad Adl and his colleagues conducted a study entitled assessing the effectiveness of detection methods to identify risks in the industry. This study was aimed at finding hazard identification methods which can identify a high percentage of total hazards of the system. At first, five methods (FMEA, AEA, HAZOP, PEME, and MORT) and number of hazards identified in any method were determined and then, effectiveness factor of risk was calculated for them that the number of identified hazards by HAZOP method and thus effectiveness factor of hazard identification of this method was more than the other methods. Results showed that the HAZOP method can detect more risks compared to other methods; but if it is used alone, 40 percent of risks are probably identified (11). Study result of Mr. Tixier J entitled "Reviewing 62 risk analysis methodologies of industrial plants in 2002 was that although the HAZOP is able to identify more risks, the method is not able to identify some of the risks involved in the process that would have to be identified with other method (12). Mr. AngellaPully in 1993 in an article entitled "Use and result of HAZOP in oil refinery" came to the conclusion that more than 57% of identified hazards by HAZOP method in the refinery is operational risks (13). Mr. Hoepffner in 1989, in his study entitled "Analysis of HAZOP study and its comparison with safety systems similar to gas purification and separation" stated that HAZOP is more successful to identify the risks compared with FMEA and FTA methods, because FTA is an inductive method which moves from whole to part and FMEA is a deductive method which moves from part to whole and HAZOP is in the middle of these methods (4). Mrs. Zainab-al-Sadat Nezamoddini in her study also stated that the highest levels of risk was related to human errors and hardware defects (14). Since the percentages of low risk levels and percentages of high risk levels identified by what if method were higher than the HAZOP method, therefore it seems what if has greater ability for identifying at low risk levels and percentages of high risk levels. Overall in this study, the total percentage of risk with unsuitable conditions (moderate) at nodes examined was much more than the low and high risk levels. In HAZOP method, percentage of moderate risk levels (total percentage of risk with unsuitable condition) was more than the high risk levels and the percentage of intolerable (high) risk was more than the percentage of tolerable (low) risk; and in what if method, the percentage of moderate risk levels (percentage of total risk with unsuitable condition) was higher than the high risk levels and percentage of risk with intolerable (high) situation is greater than the percentage of tolerable (low) risk status. CONCLUSION Assessments carried out showed that: In identifying the number of potential risks in this study, what if has higher ability than the HAZOP. In study conducted, what if has been able to identify risks with low and high risk levels and HAZOP has been able to identify risks with moderate risk levels. The cost of removing risks in the study with HAZOP method is more than the one in what if method (a higher percentage of intolerable risks by what if method is controlled with low cost compared to the HAZOP). According to the study conducted, although what if method has more ability to identify the risks compared to HAZOP method, it is suggested that at least several methods to identify risks to be used, because identifying risks with an approach is not sufficient. It seems complexity of what if method to identify risks is less than the HAZOP method. In this study, time and cost required to assess with HAZOP method was more than the ones in what if method. 1101

6 REFERENCES Occupational Safety & Health BureauDepartment of Labor and Industry,,. Job Safety AnalysisIdentification of Hazards. Ramin, Z., Human Error Assessment in Cement Factory With HRMS Method, Master science Thesis, University of Tehran Mostert L, R Coetzee A. Central oxygen pipeline failure. Southern African Journal of Anaesthesia and Analgesia. 2014;20(5):7-214 Brauer RL. Safety and health for engineers: John Wiley & Sons; Loomes G. (How) Can we value health, safety and the environment? Journal of economic psychology. 2006;27(6): Watson WL, Ozanne-Smith J. The cost of injury to Victoria: Monash University Accident Research Centre Melbourne; Miller TR, Galbraith M. Estimating the costs of occupational injury in the United States. Accident Analysis & Prevention. 1995;27(6):7-741 Khan FI, Abbasi S. Techniques and methodologies for risk analysis in chemical process industries. Journal of Loss Prevention in the Process Industries. 1998;11(4): Summers A, Vogtmann W, Smolen S. Improving PHA/LOPA by consistent consequence severity estimation. Journal of Loss Prevention in the Process Industries. 2011;24(6): Mohamadfam i. Safety Engineering. 3ed. Hamedan: Fanavaran[persian]; Kotek L, Tabas M. HAZOP study with qualitative risk analysis for prioritization of corrective and preventive actions. Procedia Engineering. 2012;15-42:808 Tixier J, Dusserre G, Salvi O, Gaston D. Review of 62risk analysis methodologies of industrial plants. Journal of Loss Prevention in the process industries. 2002;15(4): Mohammadfam E, Zamanparvar A. The evaluation of workers unsafe acts in godazan foundry in Zegordi H, Rezaee E, Nazari A, Honari F. Provide a model for risk reduction in power plant project based multi-objective optimization approach and fuzzy analytic hierarchy process. Energy Economics Studies. 2011;31: Rausand, M(2005), hazard&operability study(hazop). 1102

Hazard Operability Analysis

Hazard Operability Analysis Politecnico di Milano Dipartimento di Energia HAZOP Qualitative Deductive (search for causes) Inductive (consequence analysis) AIM: Identification of possible process anomalies