The Serious Explosion Incident on “10·8” at Chengli Gas Supply Co., Ltd., Boxing County, Binzhou City, Shandong Province (Case Analysis)

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The Serious Explosion Incident on \"10·8\" at Chengli Gas Supply Co., Ltd. in Boxing County, Binzhou City, Shandong Province (Case Analysis) Source: China Chemical Safety Association. Added on: 2016-12-19 16:15:29. Views: 145. I. Accident Investigation and Analysis (I) Overview of the Accident 1. Brief Introduction to the Accident At around 17:56 on October 8, 2013, a serious explosion occurred during the operation of the 50,000 m3 light oil-sealed dry gas holders used in the 3# and 4# coke ovens at Chengli Gas Supply Co., Ltd. in Boxing County. This incident resulted in 10 deaths, 33 injuries, and direct economic losses of 32 million yuan. 2. Cause analysis: (1) Direct cause – During the operation of the gas tank, a decrease in the viscosity of the sealing oil and a piston inclination that exceeds the specified limits led to significant leakage of the sealing oil and a drop in its level. As a result, the static pressure of the sealing oil became lower than the pressure inside the gas tank, causing the piston sealing system to fail. This allowed gas to leak from the space below the piston into the relatively sealed space above it. Continuous leakage resulted in the formation of an explosive mixture with air when it reached the explosive limit, leading to a chemical explosion upon contact with an ignition source. (2) Indirect causes: ① Boxing Chengli has a weak awareness of laws and regulations related to work safety as well as a poor safety consciousness; the main responsibilities for ensuring work safety are not fulfilled, safety management is chaotic, and there are serious violations of laws and regulations in project construction and production operations. ②The work of safety supervision departments at the city and county levels is not solid, and safety regulation efforts are ineffective. Local authorities fail to fulfill their responsibilities for managing work safety at the local level; they provide inadequate guidance and supervision regarding work safety, and their efforts to eliminate illegal and unsafe practices are insufficient. (II) Basic Information 1. Information on the units involved in the accident: Boxing Chengli Gas Supply Co., Ltd. (hereinafter referred to as Boxing Chengli) is located in the Industrial Park of Chunhua Town, Boxing County, Binzhou City. It was established in April 2006; originally it was a collectively-owned enterprise under Boxing County Power Supply Company. In July 2008, it was restructured into a private joint-stock enterprise ； The registered capital is 50 million yuan, with total assets amounting to 1.5 billion yuan. Currently, there are 1,026 employees. The legal representative is Mr. Zhang. The company’s business scope includes wholesale of coal, production and sale of coke and its by-products; production and sale of coke oven gas, coal tar, sulfur, sulfuric acid, crude benzene, and coke. Internally, the company has 20 departments and units, including a First Branch Factory, a Second Branch Factory, the Safety Supervision Department, and the Production Technology Department. There are currently two coke ovens with a capacity of 400,000 tons per year each, and two coke ovens with a capacity of 600,000 tons per year each. The main production capacities are: 2 million tons of coke per year, 110,000 tons of coal tar per year, 29,000 tons of crude benzene per year, and 23,000 tons of ammonium sulfate per year. There are also 45 kilometers of gas pipelines for external supply. Among them, two 400,000-ton/year coke ovens and their auxiliary facilities obtained the “Safety Production License” on January 17, 2011 (License No. Lu WH An Xu Zi 160192), which remained valid until January 16, 2014 ； The two 600,000 tons per year coke ovens and their associated facilities (the project is named Project 3# and 4# Coke Ovens) have not yet applied for the completion inspection of the safety facilities for hazardous chemical construction projects, and are still in the trial production phase. The legal representative of Boxing Chengli was Zhao in July 2008, following the company’s restructuring; it was changed to Zuo in April 2009 (who is currently the manager and member of the Party committee at Boxing County Power Supply Company); it was changed to Li in October 2010 (who is currently the deputy manager at Boxing County Power Supply Company and a director of Boxing Chengli); and it was changed to Zhang in May 2013. Currently, the shareholders of Boxing Chengli are 36 natural persons; among them, Mr. Zhang has invested 5.2 million yuan, accounting for 10.4% of the company’s capital and making him the second-largest shareholder of the company. 2. Status of the 3#, 4# Coke Ovens Project: The 3# and 4# coke oven projects of Boxing Chengli are part of the company’s second phase of development. The main facilities include 2 coke ovens with an annual production capacity of 600,000 tons each, coal preparation units, gas purification systems, chemical product recovery units, and a 50,000 m3 dilute oil-sealed dry gas holder (hereinafter referred to as the gas holder). Construction of this project (excluding the gas holder) began in September 2010, was completed in November 2011, and trial operation started in March 2012. ①Project design, construction, and engineering supervision. The preliminary design unit is: MCC CERAMIC (Dalian) Engineering Technology Co., Ltd. The construction drawing design unit (excluding the gas holder) is: MCC Coking & Refractory Engineering Technology Co., Ltd. The construction contractor (excluding the gas holders) is China Sanye Group Co., Ltd. (hereinafter referred to as China Sanye), which is responsible for the construction of the No. 3 and No. 4 coke oven systems, while China Ershierye Group Co., Ltd. (hereinafter referred to as China Ershierye) is in charge of the construction of the chemical production plant systems. The project supervision unit is: Shandong Zhongcheng Construction Project Management Co., Ltd. (hereinafter referred to as Shandong Zhongcheng). The qualification levels and scope of operations of the aforementioned design, construction, and project supervision units all meet the relevant regulatory requirements. ②Information on project approvals. In August 2008, the Boxing County Planning Bureau issued the “Opinions on the Site Selection for the No. 3 and No. 4 Coke Ovens Project of Boxing Chengli Gas Supply Co., Ltd.” (Document No. Bo Gui Han 28). In February 2009, it received the approval from the Binzhou Development and Reform Commission regarding the 1.2 million t/a coking project of Boxing Chengli Gas Supply Co., Ltd. (Document No. Bin Fa Gai Gong Ye 121). In January 2013, the Binzhou Public Security Fire Brigade issued the \"Fire Protection Inspection Opinion for Construction Projects\" (Bin Gong Xiao Yan No. 0001). ③Project safety review and trial production status. Since the project started construction without prior approval for safety compliance, in November 2011, the Work Safety Supervision Bureau of Boxing County took legal action against it under reference D006]. Subsequently, the enterprise began applying to redo the relevant security review procedures. In January 2012, the Binzhou Work Safety Supervision Bureau issued the “Opinion on the Safety Permit for Construction Projects Involving Hazardous Chemicals” (Document No. Bin’anjian Weihua Project Shenzi 4), approving the application for the safety assessment of the project ； In April 2013, the \"Safety Permit Opinion for Hazardous Chemicals Construction Projects\" (Bin An Jian Gui Hua Project (Design) No. 27) was issued, approving the special section on the design of safety facilities for the project ； In June 2013, the \"Notice on the Filing of the Trial Production (Operation) Plan for Hazardous Chemicals Construction Projects\" (Bin An Jian Wei Hua Project Bei Zi No. 28) was issued, whereby the trial production plan for the project was filed; the trial production period ran from June 17, 2013, to December 16, 2013. 3. Details of the gas holder where the accident occurred: Construction of the gas holder began in October 2011 and was completed in July 2012. It was put into trial operation in September 2012. It is under the management of the Chemical Products Workshop affiliated with Boxing Chengli Second Branch Plant, which is responsible for the production operations of the No. 3 and No. 4 coke oven systems. ①Main components and their contents in coke oven gas: hydrogen (55.0–60.0%, on a volume basis), methane (23.0–27.0%), carbon monoxide (5.0–8.0%), oxygen (0.3–0.8%), ethane (2.0–4.0%), carbon dioxide (1.5–3.0%), nitrogen (3.0–7.0%), along with small amounts of hydrogen cyanide, hydrogen sulfide, etc. The explosive limit of coke oven gas is 6.0–30.0% (by volume). It has a low lower explosive limit, a wide range, and a high hydrogen content, making it highly prone to flashback explosions. ②Uses of gas cabinets and gas supply and delivery processes. The gas produced by Boxing Chengli is mainly supplied to the gas turbines in the company’s own thermal power plant as a power fuel. The remainder is transported via pipelines to surrounding enterprises for use as fuel. The main gas pipelines of coke ovens 3# and 4# are connected to the main gas pipelines after the benzene washing towers in the systems of coke ovens 1# and 2#. The coke oven gas, after being purified, is sent to the gas holder through these pipelines. The inside of the gas holder is equipped with a piston that can move up and down; the space below the piston stores gas, while the space above it is in communication with the atmosphere. When gas enters the area below the piston of the gas holder and the pressure of the incoming gas reaches a certain level, the piston begins to rise ； When the gas reserve in the space below the piston decreases, the piston begins to descend. Under normal operating conditions, the piston moves up and down reciprocally within the gas holder, thereby storing and supplying coke oven gas and stabilizing the pressure in the gas pipeline network. ③Gas holder structure, main parameters, and safety devices. The gas holder is a dry-type gas holder with light-oil sealing; it has a regular 20-sided steel structure. It mainly consists of side plates, a bottom plate, a top plate, a piston, sealing devices, columns, a ventilation tower, an external elevator, and an internal cage. On the outside of the bottom portion of the gas holder, there are an elevator machine room, an oil pump room, and a gate chamber. The main parameters are: nominal volume of 50,000 m3, effective volume of 48,791.16 m3, design pressure of 3,500 Pa, piston stroke of 44.4 m, and total height of the cabinet at 59.786 m. The safety devices include: a light oil sealing mechanism, piston guide wheels and anti-rotation devices, an oil pump station, a mechanical cabinet capacity indicator, a piston tilt measurement device, automatic control and monitoring alarm systems, and a venting and emptying device. ④Design, construction, and project supervision of gas cabinets. The design unit for the construction drawings is: China North Engineering Design and Research Institute for Municipal Engineering (qualification level: Class A for comprehensive engineering design qualifications). The construction contractor for the civil engineering work related to the gas cabinets is China 22nd Metallurgical Construction Company. Yangzhou Tongchuang Chemical Equipment Installation Co., Ltd. (hereinafter referred to as Yangzhou Tongchuang, with a qualification level of Grade II for specialized contracting in the installation of chemical and petroleum equipment and pipelines) is responsible for the construction of the gas cabinet structures themselves as well as some of the civil engineering works. No engineering supervision was implemented for the gas holder. After the construction was completed, Boxing Chengli, without professional design, arbitrarily installed electrical equipment such as lighting spotlights and camera sensors inside and on top of the gas tank, and the installation did not comply with the requirements of the \"Code for Design of Electrical Installations in Explosive and Flammable Environments\" (GB50058). ⑤Technical instructions for gas cabinets, testing, project acceptance, and commissioning status. Boxing Chengli did not request the design firm to provide technical explanations related to the engineering work, to offer guidance during the construction process, or to participate in the testing and commissioning of the gas tank ； Nor were the project design and construction units organized to conduct engineering acceptance of the gas holder in accordance with relevant standard regulations. The gas holder was subjected to airtightness tests and pressure testing by Yangzhou Tongchuang. The checks for design omissions prior to the trial production of the gas holder, the inspections of engineering quality and potential hazards, as well as the filing of trial production (operation) plans, all fail to comply with the provisions of the \"Shandong Province Safety Commissioning Guidelines for Chemical Plants (Trial Version)\". 4. Situation of personnel at the accident site: Boxing Chengli Branch 2 has a total of 331 employees, operating on a three-shift system; 81 employees were working at the time of the accident. The China Sanye construction team has 22 workers working at the plant site. Apart from 5 to 6 workers who are resting in a temporary prefabricated house located about 100 meters north of the office building in the chemical production workshop, the rest are working at the construction site, which is situated around 300 meters from the explosion site. Binzhou Jiemei Equipment Installation Co., Ltd. (hereinafter referred to as Binzhou Jiemei) had 13 workers, most of whom were migrant laborers employed from the villages surrounding the company. It was off-shift time at that moment, and the workers were heading home one after another from the factory premises. (III) Time sequence of the accident: Date and time description – After September 25, 2013, the level of the piston seal oil in the gas holder showed a downward trend. After September 30, the 10 gas detection alarms in the gas cabinet started giving frequent alerts. After October 1, the level of the sealed oil generally dropped below 200 mm (the normal control standard is 280±40 mm). Regarding the above abnormalities, the operators in the chemical production workshop of Boxing Chengli Branch Factory reported them on multiple occasions, yet the person in charge of the branch factory failed to take any appropriate action. On October 2, Boxing Chengli Security Department issued a notice requiring the rectification of potential hazards, ordering an investigation into the reasons for the alarms issued by the combustible gas detectors in the gas cylinders. At 11:00 on October 5, an inspection of the chemical production workshop revealed leakage points at 6–7 column corners on the southeast side of the gas holder, as well as another leakage point on one of the sliding plates ； The person in charge of the second plant also failed to take any appropriate safety measures; instead, they ordered that the gas holder be put back into operation at 16:00 on the same day. At 17:00 on October 5, an alarm was triggered indicating that 2–3 monitoring points inside the gas tank were at full scale. After October 6, the carbon monoxide gas detection alarm in the gas holder continued to give alarms, yet the company still failed to take any effective measures. During this period, the equipment manufacturer was contacted to prepare for the maintenance of the gas holder. Operation at the low level of the gas holder began in the early hours of October 8. From 8:00 on October 8 until just before the accident, all 10 detection and alarm devices inside the gas tank issued overload alarms. From 10:54 to 13:00 on October 8, zero liquid level was detected at 2 monitoring points for the seal oil level. From 13:00 to 15:00 on October 8, the liquid level rose slightly. From 15:00 to 17:00 on October 8, it dropped to zero level again. At 17:45 on October 8, the operators on duty at the gas holder began to conduct inspections of the area surrounding the gas holder as well as areas such as the seal oil pump room. At 17:56:34 on October 8, the gas tank suddenly exploded. The explosion caused complete destruction of the gas tank itself; some buildings and structures within a radius of about 300 meters collapsed or were damaged. The glass in the doors and windows of buildings within a radius of about 2000 meters was damaged to varying degrees. Additionally, the crude benzene leaking from the washing towers and distillation towers in the crude benzene processing section on the north side of the gas tank, along with the used lubricating oil in the ditches on the north side of the power plant, were set alight, resulting in a large fire. (IV) Accident losses: This accident resulted in 10 deaths and 33 injuries, of which 4 were severe and 29 were minor. Among the 10 deceased, 4 were employees of Boxing Chengli, 4 were members of the China Sanye construction team, and 2 were members of the Binzhou Jiemei construction team. http://www.chemicalsafety.org.cn/uploads/allimg/161219/7-161219161Q9443.jpg http://www.chemicalsafety.org.cn/uploads/allimg/161219/7-161219161S11V.jpg Figure 1: Accident scene http://www.chemicalsafety.org.cn/uploads/allimg/161219/7-161219161UA51.jpg http://www.chemicalsafety.org.cn/uploads/allimg/161219/7-161219161Z9607.jpg Figure 2: Accident scene http://www.chemicalsafety.org.cn/uploads/allimg/161219/7-161219161922449.jpg http://www.chemicalsafety.org.cn/uploads/allimg/161219/7-161219161933341.jpg Figure 3: Accident scene (V) Analysis of accident causes 1. Analysis of direct causes During the operation of the gas tank, a decrease in the viscosity of the sealing oil and an inclination of the piston beyond the specified limits led to significant leakage of the sealing oil and a drop in its level. As a result, the static pressure of the sealing oil became lower than the pressure of the gas inside the tank, causing the piston sealing system to fail. This allowed gas to leak from the space below the piston into the relatively sealed space above it. Over time, this continuous leakage resulted in the formation of an explosive mixture with air when it reached the explosive limit. An ignition source could arise from the operation of the four non-explosion-proof aviation obstacle lights at the top of the tank, or from the live electrical circuits of the video cameras and spotlights inside the tank, or from friction between the guide wheels of the piston and the guides due to the piston’s inclination, leading to a chemical explosion. ①Formation of explosive gas mixtures: Since the gas holder was put into service, the sealing oil has never been replaced. Tests on its modification revealed non-conformities such as a decrease in viscosity and severe rust formation. After September 25, the seal oil level showed a downward trend. More than two hours prior to the incident, the oil level at both monitoring points dropped to zero. The difference in oil levels between opposite points exceeded the permissible range, and the piston tilt angle went beyond the process specifications ； This resulted in a large leakage of seal oil; the hydrostatic pressure of the seal oil became lower than the pressure of the coal gas inside the gas holder, causing the piston sealing system to fail. After September 30, the 10 carbon monoxide detection probes installed above the pistons frequently triggered alarms; after 8:00 on October 8, all of them gave out out-of-range alarms. It can be proven that before the accident occurred, the gas at the bottom of the gas tank piston had broken through, penetrated the sealing oil, or caused a short circuit, resulting in leakage into the relatively sealed space above the piston. Through continuous leakage over an extended period of time, as well as significant leakage on the day of the accident, the gas mixed with air to form an explosive mixture. In the accident investigation, the possibility that gas entered the gas system from either before the gas compressor in the air-cooled鼓 section or after the cold鼓 section up to the inlet of the gas holder—forming an explosive mixture that reached its explosion limit and thereby causing an explosion—was ruled out. Nor was there any evidence found of inherent defects in the design, manufacture, or installation of the gas holder and its sealing mechanism that could have led to gas leakage. ②Possible ignition sources: There are 4 sets of non-explosion-proof aviation obstruction lights installed on the top of the gas tank; they turn on automatically based on the level of ambient light. In the event of an explosion, these 4 sets of aviation obstruction lights are in a position to be turned on, making them one of the possible ignition sources. The video cameras and spotlights inside the gas tank were not professionally designed or installed; their switches are controlled by the neutral wire rather than the live wire, and the circuits remain energized whether they are on or off, which also constitutes one of the possible sources of ignition. Since the gas holder came into operation, no regular oiling maintenance has been carried out on the guide wheels. Before the accident, the piston’s inclination exceeded the specified process control limits; it is possible that the guide wheels became stuck or rubbed against the guide rails during operation, which means that the possibility of ignition energy being generated cannot be ruled out. In the accident investigation, factors that could have caused the explosion—such as open flames, lightning strikes and electrostatic discharge, sparks generated by repair workers’ studded shoes or their work activities, and arson—were ruled out. ③At the time of the incident, the height of the piston in the gas holder was 11.8 m. The volume of coal gas stored below the piston was 12,000 m³. Above the piston, there was a relatively sealed space of approximately 44,801 m³ where an explosive mixture of gases formed; this space accounted for about 76% of the total volume of the gas holder. The T*T equivalent explosion model was used to simulate and calculate the accident, and it was found that the energy generated by this explosion was equivalent to approximately 7323 kg of T*T equivalent. 2. Analysis of indirect causes: ① Boxing Chengli lacks a strong sense of law and safety awareness regarding work safety; the primary responsibilities for ensuring work safety are not fulfilled, safety management is chaotic, and there are serious violations of laws and regulations in project construction and operations. 1) Giving illegal instructions on a serious scale. When major safety issues such as a decline in the quality of the seal oil in the gas tank, a drop in oil level, and frequent alarms from the carbon monoxide detection system were identified, along with multiple reports from employees, the company’s management failed to pay attention to these problems and did not take any effective safety measures. In particular, on the day of the incident, with zero liquid level in the gas tank’s sealing oil, the detection alarms indicating full scale, and a large amount of gas leaking, the company’s management failed to take decisive action to shut down the system urgently or eliminate the hazards. Instead, they continued to operate the gas tank at a low level, allowing it to function despite being in a faulty state, until the accident occurred. 2) The problems related to the daily maintenance and management of equipment are severe. After the gas holder was built and put into operation, the company failed to carry out regular inspections, maintenance, and servicing of the piston and sealing devices inside the gas holder, as required by the \"Safety Regulations for Gas in Industrial Enterprises\" (GB622), nor did it apply lubricant to the shafts of the guide wheels on a regular basis. Even after receiving the report on the seal oil modification experiment and becoming aware of the decline in the quality of the seal oil, no actions were taken such as replacing it or adding modifiers to improve its quality, which led to further deterioration of the seal oil’s quality until a gas leak occurred. 3) Construction and production in violation of laws and regulations. The construction of the company’s No. 3 and No. 4 coke ovens began in October 2010, with trial operations starting in March 2012. Throughout this period, no applications were submitted for reviews regarding the safety conditions required for hazardous chemical production projects, nor for approvals of the designs related to safety facilities or for documentation of the trial production plan. Construction and production proceeded in violation of regulations for a long time, until the Boxing County Safety Supervision Bureau took legal action against them in November 2011; only then did they apply to complete the necessary procedures. There are violations of **laws, regulations, and standard requirements in all aspects of the gas holder’s development, equipment procurement, construction, acceptance, and trial production. The main issue is that the electrical equipment used in areas prone to explosions was not selected in accordance with the specifications outlined in the design documents; instead, non-explosion-proof electrical equipment was used ； The design unit was not consulted for technical instructions prior to construction ； Project supervision was not carried out during the construction process ； After the construction was completed, no inspection was carried out in accordance with relevant standards and specifications; furthermore, certain electrical instruments were installed inside and on top of the gas tank without any professional design ； During the trial production phase, the power supply failed to meet the requirement of dual-power supply assurance specified in the \"Special Guidelines for Safety Facility Design.\" Moreover, the \"Procedures for Safe Commissioning of Chemical Plants in Shandong Province (Trial Version)\") was not strictly followed during this trial production process ； There is a lack of relevant documentation for the construction of gas cabinets, etc. 4) Poor management of external construction teams. Before the accident occurred, there were 5 external construction teams working within the company’s premises, carrying out construction activities while production continued. These teams did not have adequate safety management systems, and there were no proper safety controls in place for the construction work. Moreover, temporary shacks were built about 100 meters north of the office in the chemical production area, allowing workers to live and stay there within the production zone, which contributed to an increase in casualties as a result of the accident. 5) The safety production management system is imperfect and not properly implemented. The enterprise has failed to establish sound safety management systems and operating procedures for the inspection, maintenance, and upkeep of gas tanks in accordance with the \"Safety Regulations for Gas in Industrial Enterprises\" (GB622). It has also not set up any system for analyzing and controlling the quality parameters of seal oil. The responsibilities related to safe production as well as various safety regulations are not properly implemented, and the enterprise’s main responsible persons do not possess the required safety certification. 6) Safety training and education are a mere formality. The management and operators of the enterprise are unaware of the harmful consequences that can arise from abnormalities in the gas tank, and they fail to handle emergency situations or handle them incorrectly. Many operators are not familiar with the operating procedures and process parameters, do not understand the meaning of these parameters, and lack awareness of the dangerous and harmful factors present in their work areas; as a result, the operation processes are not carried out properly and the operation records are incomplete. The safety awareness and operational skills of employees are low, and the effectiveness of safety training is poor. ②The work of safety supervision departments at the city and county levels is not solid, and safety regulation efforts are ineffective. 1) The Work Safety Supervision Bureau of Boxing County is responsible for the comprehensive supervision and management of work safety across the county. It is in charge of the approval process as well as the overall supervision of work safety in hazardous chemicals enterprises within the county. Additionally, it is responsible for overseeing the simultaneous design, construction, and commissioning of safety facilities alongside the main structures of the Boxing Chengli Phase II project. Failing to fulfill safety supervision responsibilities adequately, failing to effectively urge and guide enterprises in the region to assume their primary responsibilities for safe production, and failing to conduct thorough inspections of safety conditions in the region. Since 2012, multiple safety inspections have been conducted on Boxing Chengli. Failure to ensure thorough and effective rectification of the illegal construction practices and safety hazards present in its operations was observed; no evidence was found of external workers staying or eating in the production area, and the company’s chaotic safety management practices went unaddressed. During this year’s comprehensive safety inspection, serious production safety hazards were identified at the Boxing Chengli gas holder. On June 5, an order was issued requiring prompt rectification, but the corrective measures taken were inadequate and merely superficial. 2) The Binzhou Work Safety Supervision Bureau failed to fulfill its responsibilities for work safety supervision, and did not provide adequate guidance for organizing work safety inspections in the region. Although the \"Key Points for the Supervision of Hazardous Chemicals Safety in the City for 2013\", the \"Work Plan for Safety Supervision and Law Enforcement for 2013\", and the \"Work Plan for Law Enforcement and Supervision by the Municipal Work Safety Inspection Team for 2013\" were issued, and major work safety inspections as well as special campaigns to crack down on illegal activities were carried out, and Boxing Chengli was designated as a key unit for supervision and inspection; nonetheless, insufficient, inadequate, and ineffective efforts were made to urge the company to rectify the safety hazards associated with its illegal construction and production practices. It was not discovered that any external workers were staying or eating in the company’s production area, and the chaotic state of work safety management at Boxing Chengli went unnoticed. ③Local authorities fail to fulfill their responsibilities for managing work safety at the local level; they provide inadequate guidance and supervision regarding work safety, and their efforts to eliminate illegal and unsafe practices are insufficient. 1) The Purjing Town government **failed to fulfill its responsibilities regarding the safe production of enterprises within its jurisdiction; it did not implement the relevant laws, regulations, and policies related to safe production, and its inspections for ensuring safe production were not thorough or comprehensive enough. Inspections of Boxing Chengli’s illegal and irregular construction and production activities were not thorough or meticulous, and the company’s chaotic safety management was overlooked. 2) The people’s government of Boxing County failed to fulfill its responsibilities for local safety management; it did not implement safety-related laws, regulations, and policies effectively. It did not exercise sufficient oversight in ensuring that the local safety supervision agencies and relevant industry authorities carried out their safety supervision duties properly, and it failed to conduct thorough inspections related to safety production. As a result, it failed to detect the issues of illegal construction, chaotic production processes, and poor safety management at Boxing Chengli. II. Emergency rescue efforts: Following the explosion of the gas tank, there was a power outage in a large area around Boxing Chengli, and large fires broke out in some parts of the factory site; the scene was in complete chaos. The enterprise employees immediately called 120 and 119 for help, took prompt action to save themselves, searched for and evacuated those injured or killed, and shut down the entrances and exits of various units in the gas pipeline and chemical production systems. The Boxing County Party Committee, the county government, along with departments and agencies such as those responsible for safety supervision, public security, fire protection, environmental protection, health, and hospitals, arrived at the accident site one after another around 18:45. They activated the emergency response plan, established a leadership team for emergency handling, and began efforts to rescue those affected by the accident. The Binzhou Municipal Party Committee, the municipal government, and relevant departments arrived at the accident scene one after another around 8:50 p.m. to take charge of the rescue efforts, and to organize operations for saving those affected by the accident, providing medical treatment to the injured, and handling subsequent matters. At around 21:00 that night, the five fire points caused by the explosion were successfully extinguished. The entire coking unit was shut down, and gas release systems were activated; cooling spray measures were continued to be applied to some of the equipment at the accident site in order to prevent secondary accidents and related disasters. During the emergency response to the accident, the Boxing County Party Committee and the county’s relevant authorities failed to provide effective organization and command, and the search and rescue efforts were inadequate. The main commanders directed operations from outside the factory for extended periods, lacking direct insight into the situation on site, which weakened their ability to effectively control the response efforts. No strong professional rescue team was organized; instead, the company was relied upon to search for victims of the accident. There was poor oversight of the people and vehicles at the accident site, which led to Boxing Chengli moving and hiding 5 deceased individuals. Another victim was not found at the accident site until the morning of the 10th, and that person was also moved and hidden by the company. III. Reflections and Recommendations In light of the prominent issues exposed by this accident, in order to thoroughly learn from it, further strengthen safety production in the chemical industry, and effectively prevent similar accidents from occurring again, the following measures are recommended: (1) Further enforce enterprises’ primary responsibility for safety production. Chemical enterprises shall, in accordance with the \"Provisions on the Primary Responsibilities for Work Safety of Production and Business Entities in Shandong Province\" (Provincial Decree No. 260) and relevant laws and regulations, clarify and specify their own primary responsibilities for work safety. They must establish a work safety responsibility system that covers all aspects both horizontally and vertically, ensuring that these responsibilities are implemented in every aspect of production and operation, at each position, and by every employee. The principal responsible persons of such enterprises shall bear full responsibility for ensuring the fulfillment of their organization’s primary responsibilities for work safety. All levels of ** and their agencies responsible for safety supervision and industry regulation must guide and urge enterprises to firmly embrace the concept of \"people-oriented, safe development,\" ensuring that safe production becomes an inherent practice for these enterprises. They should strictly comply with policies and regulations related to safe production and comprehensively strengthen safety management practices ； It is necessary to continuously strengthen safety supervision measures and improve the regulatory and policy framework, so as to provide strong policy support for enterprises to fulfill their primary responsibilities for safe production ； It is necessary to make comprehensive use of legal, economic, and appropriate administrative measures to further urge enterprises to assume their primary responsibility for safe production and continuously enhance their capacity to ensure safety in production. (II) Further strengthen the basic work on enterprise safety production. Chemical enterprises shall, in accordance with the \"Guiding Opinions of the State Administration of Work Safety on Strengthening the Safety Management of Chemical Processes\" (An Jian Zong Guan San [2013] No. 88) and relevant laws, regulations and standards, equip themselves with automated control systems to monitor and issue early warnings for key process parameters. By employing methods such as online safety monitoring, automatic data detection, or manual data analysis, they should promptly identify the causes of abnormal operating conditions, assess potential consequences, and develop safety response plans to prevent accidents resulting from improper handling. In accordance with the Interim Provisions on the Supervision and Management of Major Hazard Sources of Hazardous Chemicals (Order No. 40 issued by the State Administration of Work Safety), it is necessary to strengthen the monitoring of the operation of such major hazard sources, improve alarm systems and control mechanisms, and carry out inspections, tests, and maintenance of safety facilities as required by regulations. It is necessary to strictly implement the provisions of the \"Ten Regulations for Chemical (Hazardous Chemicals) Enterprises to Ensure Production Safety\" (Order No. 64 issued by the State Administration of Work Safety). Giving orders in violation of regulations or forcing others to carry out work in dangerous conditions is strictly prohibited; engaging in work in violation of regulations, leaving one’s post, or doing things unrelated to one’s job while at work is also strictly prohibited. Furthermore, carrying out operations such as welding, entering confined spaces, working at heights, lifting operations, using temporary electricity, digging, maintenance work, or removing/inserting blind flanges without prior approval is strictly prohibited. It is necessary to further strengthen management measures against the phenomena of violating regulations, treating such violations as safety incidents or accidents, implementing dynamic monitoring and early warning systems, and resolutely putting an end to such violations. In accordance with the requirements of the \"General Specifications for Safety Standardization of Hazardous Chemicals Handling Enterprises\" (AQ 3013), it is necessary to establish and improve safety management systems for external construction teams, incorporate these teams into the enterprise’s safety management system, apply uniform standards, requirements, and management practices, and conduct strict evaluations. It is necessary to strengthen safety controls at construction sites, especially those involving high-risk operations (such as working while production continues, partial shutdowns for repairs, or special operations under pressure). The number of people at the construction site must be strictly controlled; unauthorized personnel are prohibited from entering the construction area. It is essential to avoid carrying out incompatible operations at the same time and in the same location, to reduce simultaneous multi-level operations, and to limit work during holidays and at night. Construction workers are strictly forbidden from staying in the production facility. (III) Severely crack down on false reporting of accidents, as well as illegal construction and production and operation activities. All levels of ** and their relevant departments shall earnestly implement the regulations regarding accident reporting in the province, guide and urge enterprises to report any accidents that occur in accordance with the prescribed time limits and truthfully, verify in a timely and accurate manner the accidents reported by enterprises as well as those reported by the public, and take strict legal action against any instances of delayed reporting, omitted reporting, false reporting, or concealment of accidents. It is necessary to strengthen political and legal education for Party members, cadres at all levels, and enterprise managers, and to resolutely put an end to practices such as false reporting and concealment of information. It is necessary to maintain a high-pressure stance against illegal and irregular activities at all times, making this approach institutionalized and routine; illegal production, business operations, and construction activities must be severely cracked down on and dealt with rigorously, in accordance with the requirement of the \"four musts.\" Those engaged in illegal production and operation in the construction sector, or those that still fail to meet the requirements despite having undergone suspension for rectification, shall be shut down and banned outright ； All units and individuals involved in illegal production, operation, or construction shall be punished to the maximum extent permitted by regulations ； Units engaged in illegal production, operation, or construction are ordered to suspend operations for rectification, with strict supervision measures implemented ； All relevant units and individuals who violate the law will be held strictly accountable in accordance with the law. (IV) Accelerate the improvement of emergency rescue management capabilities. Chemical enterprises must, in accordance with **relevant laws, regulations, and standard requirements, further improve their emergency response plans, assign emergency response personnel, and provide the necessary emergency response equipment and tools, while also organizing regular emergency response drills. Personal safety and environmental protection must always be given top priority in accident emergency response. Supervisors, team leaders, and production schedulers on the site should be granted the direct authority to order the suspension of operations and the evacuation of personnel in case of danger, thereby improving the ability to handle emergencies at an early stage and minimizing or avoiding casualties as much as possible. All levels of ** and their relevant departments shall, in accordance with relevant laws, regulations, and standard requirements, and based on the actual conditions of their respective regions, promptly organize the formulation and improvement of emergency response plans for hazardous chemical accidents in those regions. With the aim of reducing casualties and losses from accidents, as well as preventing the spread and escalation of such accidents, emergency drills should be conducted regularly to continuously improve the accident response capabilities at all levels. (5) Strengthen safety supervision over enterprises that are considered “two key and one major” enterprises. Safety supervision departments at all levels must comprehensively and accurately understand the safety production conditions of enterprises in their respective regions that fall under the category of \"two key types and one major type\" of enterprises (those involving hazardous chemicals under strict supervision, hazardous chemical processes, and major hazard sources). Special attention should be paid to the safety supervision of flammable, explosive, and toxic hazardous chemicals that exist in gaseous form after leaks, as well as of large-scale hazardous chemical storage areas and chemical enterprises located near densely populated urban and rural areas. It is necessary to conduct thorough safety inspections of enterprises involved in gas production and use, to thoroughly identify and address potential safety hazards in gas production facilities, gas tanks, and transmission pipelines. Enterprises should be urged to establish and improve safety management systems, comply with relevant standard requirements, strengthen routine maintenance of equipment, ensure that safety facilities are in good working condition, and that safety management systems and operating procedures are properly implemented. (VI) Earnestly fulfill the local supervision responsibilities for work safety. Binzhou City, Boxing County ** and their relevant departments must earnestly study and implement the spirit of ****’s important speeches on work safety, and fully fulfill the local ** responsibilities for supervision at the regional level, the direct supervision responsibilities of the industry authorities, as well as the comprehensive supervision responsibilities of the safety regulatory agencies. In light of the rapid development of the chemical industry in this region, it is necessary to study and formulate appropriate policy measures, increase safety supervision resources, and strengthen the oversight of chemical enterprises. To enhance the ability to prevent accidents, it is necessary to innovate further in methods and approaches. Enforcement inspections should be carried out through random checks, surprise night inspections, open and covert investigations, follow-up reviews, cross-checks, and law enforcement in different locations. Continued in-depth inspections for work safety are required to thoroughly identify and address potential hazards. To improve the ability to investigate accidents and hold those responsible accountable, accidents that occur must be thoroughly investigated and dealt with, and those responsible must be held liable; any potential accident hazards that are not addressed in a timely manner are also considered to warrant accountability.