Reflections on safety accidents caused by issues in operating procedures

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There are scholarly reports on how issues related to operating procedures lead to safety accidents; in the chemical industry, over 40% of process safety accidents are associated with deviations from the standard operating procedures. When companies analyze the causes of such accidents, they tend to attribute them to whether employees follow the procedures, thereby overlooking the problems inherent in those procedures as key factors contributing to the accidents. We have analyzed the various causes of many accident cases and identified that the operating procedures mainly have problems in the following four areas. I. The issue of an imperfect set of operating procedures: With the improvement of relevant laws and regulations, enhanced supervision, and greater emphasis on safety management by enterprises, it is virtually unheard of for companies to lack operating procedures. However, the existence of such procedures does not necessarily mean that the system of operating procedures is complete. Numerous accident cases show that companies with poor management are like firefighters: when an incident occurs somewhere today, they create a set of operating procedures; when there’s a problem elsewhere the next day, they formulate management rules; and when an emergency arises the day after that, they develop an emergency response plan. Therefore, a comprehensive set of operating procedures can ensure that the controlled production process remains in a stable state. Case 1] Explosion in the alkali recovery furnace On March 28, 2015, an explosion occurred in the alkali recovery furnace of a certain company, resulting in multiple tears and severe deformation of the water wall, as well as displacement and detachment of the fixing brackets. According to the classification of accident severity, this was considered a major boiler equipment accident; the direct and indirect economic losses resulting from the accident amounted to over 5 million yuan. The indirect cause of the accident was the manual bypassing of the refractometer for the overly concentrated black liquor fed into the furnace, the unauthorized modification or deactivation of the interlock protections, and the use of black liquor that did not meet the technical requirements for combustion processes. People’s judgment and actions in dangerous situations are often delayed and unreliable. According to relevant data, when operators are faced with life-threatening situations, they must respond within 60 seconds; the probability of making a wrong decision is as high as 99.9%. To ensure the safe operation of production equipment, the use of safety interlock control systems has become a trend. In February 2014, we downloaded 72 case studies of instrument failures from the HaiChuan Chemical Forum, and learned about incidents caused by the activation or deactivation of interlocks. In light of the various problems such as material leaks and shutdowns that occurred during hydrogen peroxide production due to inadequate interlock management, the company formulated the \"Safety Interlock Management Regulations\". In the aforementioned Case 1, let’s ask the five whys? 1. Are there any management regulations for safety interlocks? 2. Has the training on safety interlock management regulations been conducted? 3. Do employees understand the regulations regarding safety interlock systems? 4. Why don’t employees follow the safety interlock regulations? 5. Employees fail to follow the regulations. Are the managers aware of this? First, look for the reasons in management. If you don’t have such rules, how can employees be accused of violating operating procedures or having a weak safety awareness? We often talk about using the five whys to analyze problems, but in most cases, three questions are sufficient. In daily work, we often focus on improving equipment and innovating processes, while the revised operating procedures are often neglected. New notices or regulations are issued, and the management of these operating procedures is not thorough enough. In September, an activated carbon canister was added to the exhaust gas emission pipeline of the hydrogen processing unit, and we promptly improved the operating procedures. Therefore, management should regularly review the operating procedure system to assess its adequacy. In cases where safety accidents occur due to omissions in the operating procedure system, management deficiencies are often the main cause of such accidents. As shown in the diagram of our company’s procedure system below, based on this procedure system and by referring to the procedure records, along with the task list, we analyze whether all tasks in the production process are controllable. file:///C:/DOCUME~1/ADMINI~1/LOCALS~1/Temp/msohtmlclip1/01/clip_image002.jpg II. Issues related to the quality of procedure documentation – What constitutes an effective set of procedures? Each factory and each process system is different, so there is no unified or single standard for writing operating procedures. The reality is that most operating procedures are of poor quality and lack practicality. Based on the operational characteristics of the chemical industry and taking into account the experience in hydrogen peroxide production, the operating procedures for hydrogen peroxide production should consist of three parts: operational guidelines, step-by-step instructions, and job safety analysis. 2.1 The operation guidelines section is intended to highlight matters that require special attention from employees, with the goal of enhancing their safety awareness and preventing risks resulting from improper operations. 2.2 The operation steps section mainly details the operations, breaking them down into several smaller tasks. 2.2.1 The content of the operation steps is further divided into three parts: pre-operation checks and preparations, the operation process, and post-operation tasks. 2.2.2 Requirements for writing operating procedures ⑴ Clearly define responsibilities and ensure close cooperation. The operating procedures should specify the person responsible for each task, so as to prevent work safety accidents caused by unclear division of labor and poor communication. ⑵3. The operational steps are complete and detailed; 2.3 Safety analysis of operational steps: Existing production procedures are often separate from those related to safe production, which prevents employees from following a systematic set of procedures in their work, thereby increasing the likelihood of unintentional actions being taken. Adding an analysis of operational safety to the operating procedures can effectively integrate the two aspects, thereby enhancing employees’ safety awareness during operations. Currently, Hazard and Operability (HAZOP) analysis methods, both domestically and internationally, are primarily used for risk analysis of industrial processes, whereas many accidents are caused by deviations in human operation. Whether operators are at risk while carrying out a procedure, how to analyze this risk, and how to avoid it – these are the issues that operational hazard assessment focused on procedures aims to address. This evaluation not only corrects the flaws in the operating procedures but also helps operators understand not only what to do in each step of those procedures but also why it is necessary to do so, thereby ensuring that the safety measures related to the operators function effectively. Extensive practical statistics show that deviations by operators in following the operational steps fall into two main categories of problems: (1) What happens if steps are skipped (which can also be referred to as omissions)? ⑵What happens if the operation steps are not carried out correctly (even without any skipping)? Behind deviations in operating procedures lies human unsafe behavior; therefore, how can safety analysis within operating procedures be conducted with the aim of controlling such behavior and minimizing its occurrence? The renowned British psychologist Reason elaborated on his ideas in his book Human Error (1990). Reason believes that most people’s mistakes are unintentional, caused by careless negligent actions ； Some mistakes are intentional, meaning the operator uses an incorrect set of plans or strategies to solve a problem, but believes it to be the correct or better method. Intentional acts of destruction by humans are not taken into consideration. Reason’s classification framework for safe human behavior is shown in the figure below: file:///C:/DOCUME~1/ADMINI~1/LOCALS~1/Temp/msohtmlclip1/01/clip_image004.jpg For example, the operating procedures for starting up the device using hydrogen peroxide involve 37 steps and 401 specific actions; more than 400 valves need to be checked before starting up, and it is common to overlook the failure to open certain valves during this process. If the butterfly valve on the vertical pipe of the hydrogen pressure tower is not opened at startup, it will cause leakage at the gasket of the filter for the circulating working fluid. Similar situations all fall under unintentional behaviors that constitute unsafe actions. In our actual work, there are very few instances of genuine intentional behavior; therefore, when employees make mistakes, we cannot simply assume that they have violated regulations. HAZOP uses guiding words to analyze unintended behaviors, and based on the analysis results, it feeds back into the operating procedures to add missing items, precautions, warnings, annotations, tips, and accident handling guidelines. In reality, many operating procedures were borrowed from Baidu; their quality still needs to be improved. We studied the formulation rules of TOTAL’s “OPERGUID” in France, and spent over five years developing the \"Operating Procedures for Hydrogen Peroxide Production via the Anthraquinone Process\", which ensured stable operation in hydrogen peroxide production. However, there are still many shortcomings, such as insufficient safety analysis in these operating procedures. III. Issues with the templates for drafting operating procedures: Current operating procedures are mainly presented in the form of plain text, which presents problems such as lack of intuitiveness, difficulty in memorization, and challenges in self-study. The operating procedures for diagram culture are more intuitive, making them easy to understand at a glance; they also facilitate memory and recall during on-site operations, allowing new employees to master them and apply them effectively in a short amount of time. In particular, by adding visual risk control measures to identify potential hazards at each step of the process, the operating procedures become more informative, which helps operators enhance their safety awareness and improve their ability to recognize risks. However, compiling illustrated operating procedures is a rather difficult task. It requires a great deal of effort, and the compilers must be highly experienced. Moreover, when there are changes to processes, equipment, etc., it often proves difficult to promptly update and improve the operating procedures accordingly. IV. Case Studies on Training Regarding Operating Procedures: The Incident of the Tripping of the Rectifier Transformer at Inner Mongolia Yihua Caustic Soda Plant I. Accident Overview On the afternoon of March 13, 2010, the temperature of the pure water used in the rectifier transformer gradually increased, and the dispatch center instructed the on-duty operators to replace the water. However, during the water change process, rectifier transformers #1, #2, and #3 stopped operating instantly, and the current for caustic soda dropped from 40 KA to 1.5 KA. Upon checking the computer’s historical data, it was found that a decrease in the pressure of pure water was the cause of the rectifier transformer shutting down. II. Causes of the accident: 1. Mistakes were made by the operator on duty; he used a water-changing method that involved draining water first and then adding more water, and these errors led to the tripping of three rectifiers. 2. The electrical control department did not pay enough attention to training; it merely distributed the procedures for cooling down the system to the operating staff, without conducting tests in a timely manner. III. Rectification Measures 1. When a mistake keeps recurring in a certain issue, as a manager, it is necessary to consider two things: First, are there any errors in the way things are done? This accident is not the first of its kind; the electrical control department should promptly review whether there are any errors in the operating procedures and whether they may be misleading to the employees II. Are there any misunderstandings in the subordinates’ thinking? Regarding the multiple misoperations of the rectifier transformer, is there a situation where actual operations differ from the operating procedures? 2. Insufficient awareness of the importance of training and examinations. Before an incident occurs, many people tend to view training and exams related to the operating procedures as a burden, seeing them as an additional load on top of their work; it is only after an incident happens that they realize just how superficial their understanding of the subject matter really is! With operating procedures in place, have the employees been trained? Can it be mastered after training? Training is receiving increasing attention from enterprises; at the same time, various problems related to it are being identified more frequently. There are also issues with training procedures, such as single-minded training methods and limited evaluation effectiveness. The content of operating procedures is rather dull, and in terms of training methods, companies mostly use traditional approaches such as \"the instructor lectures, the trainees listen, and exams are used for assessment,\" which leads to boredom and poor results, causing employees to lose interest in training. The discussion-based, learning-oriented, lecture-style, game-based, case analysis, and modular training methods developed abroad are worthy of our reference. The methods used in the evaluation of operating procedures are limited; the vast majority of companies merely conduct examinations as part of training, and no further follow-up analysis is carried out after those exams. Exams are an effective method of assessment, but they have certain limitations and constraints – not all training content is suitable for evaluation through exams. Additionally, employees may focus on preparing for the exams, which means that the results obtained after the exams do not reflect the actual situation. Sometimes, exams are merely a formality, with poor actual results. In September 2014, we began to develop training procedures for the finger-spelling method; after more than a year of implementation, certain results were achieved, but there are still many issues that need to be improved. Conclusion: Operating procedures are an important aspect in preventing safety accidents, yet their significance has not yet been given due attention. In production, we focused on the benefits brought about by equipment improvements and process innovations, while neglecting the follow-up and improvement of basic management practices such as operating procedures. There are countless examples where the losses caused by an accidental mistake far exceed the benefits resulting from improvements. Why must we change our mindset and, with the attitude of working diligently like a coolie, solidly strengthen our basic management? On the other hand, it is necessary to keep learning to improve management skills. Dalian West Pacific Petrochemical Co., Ltd. invested 300,000 francs to acquire the rights to use Total’s French \"OPERGUID\" operating procedures. “The patent rights for “OPERGUID” attest to its management level. From a higher perspective, our operating procedures are at a rudimentary level; it’s no wonder so many safety accidents occur. 1. Reliability Analysis of Humans: Needs, Conditions, and Progress, Journal of Central South Institute of Technology, June 1996, Volume 13, Issue 2. 2. Basics and Applications of Hazard and Operability Analysis (HAZOP), edited by Wu Chongguang, China Chemical Safety Association. 3. Process Safety Management and Accident Prevention, by Li Zhenyu, Sinopec Press