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I. Typical accidents in October 2016 (1) On October 9, a leakage and fire accident occurred at the feed filter of the reforming complex at Sinopec Jinling Petrochemical in Nanjing, Jiangsu Province; no injuries were reported. Preliminary analysis indicates that the direct cause of the accident was a failure in the sealing of the gasket at the flange of the feed filter head, which led to a leak of mixed aromatics from within the filter (at a pressure of 0.96 MPa and a temperature of 145°C). The high-speed expulsion of these materials generated static electricity, resulting in a flash fire. (II) On October 10, an explosion occurred in an ethanol recovery tank in the wastewater recycling workshop of Qilu Tianhe Huisi Pharmaceutical Co., Ltd. in Jinan City, Shandong Province; no injuries were reported. Upon investigation and analysis, the direct cause of the accident was that after the valves were closed at the diphenylhydrazide recovery distillation tank in the wastewater recovery workshop upon completion of distillation, steam leakage from the valve caused the temperature inside the tank to rise. This led to the decomposition of substances such as hydrazine hydrate and diphenylhydrazide present in the residual liquid within the tank, generating a large amount of gas. As a result, the pressure inside the tank increased and exceeded safe levels, leading to an explosion. (III) On October 14, a leakage and explosion occurred in a syngas compressor at Jin Kai Chemical Industry Investment Holding Group Co., Ltd. in Kaifeng City, Henan Province; no casualties were reported. Preliminary analysis indicates that the direct cause of the accident was the failure of a gland bolt at one of the air inlets on the sixth stage of compressor No. 5 in the compression section of the second system’s synthesis workshop, which belongs to one of the subsidiaries of that corporate group. This led to a leakage of the mixture of hydrogen and nitrogen inside the compressor (at a working pressure of 10.5 MPa), which formed an explosive mixture with air. An ignition source or static electricity generated by friction from high-pressure gases caused an explosion. II. Chemical and hazardous materials accidents that occurred in November throughout history (I) Domestic accidents: The \"11•5\" poisoning accident at Huaxin Branch of the Fertilizer Factory in Kaihua County, Zhejiang Province On November 5, 1997, a hydrogen sulfide poisoning accident occurred at Huaxin Branch of the Fertilizer Factory in Kaihua County, Zhejiang Province, resulting in 3 deaths. At the time of the incident, workers in the factory were cleaning the residue inside a carbon disulfide reaction vessel. Due to the large amount of dust present in the vessel, the workers decided to sprinkle water inside it in order to reduce the dust level. However, as the water came into contact with the residue, it reacted with the remaining carbon disulfide, releasing hydrogen sulfide gas, which caused the workers on site to be poisoned. The \"11•6\" explosion and fire accident at Songyuan Petrochemical in Jilin Province On November 6, 2011, an explosion and fire accident occurred at Songyuan Petroleum Chemical Co., Ltd. in Jilin Province, resulting in 4 deaths and 7 injuries. The direct cause of the accident was that microcracks appeared on the head of the reflux tank at the top of the deethanizer in the gas fractionation unit due to hydrogen sulfide-induced stress corrosion. These microcracks continued to expand, resulting in minor fractures in the heat-affected zone near the welds on the tank head, which eventually led to its complete rupture. A large amount of the medium inside the tank (a liquid mixture of ethane and propane) leaked out; when this mixture mixed with oxygen in the air and reached its explosive limit, it ignited upon contact with an open flame, causing a flash explosion and subsequently a fire. The \"11•7\" leakage and explosion accident at Chongqing Changfeng Chemical Plant in Changshou County, Chongqing On November 7, 2001, an explosion and fire broke out at Chongqing Changfeng Chemical Plant in Changshou County, Chongqing, resulting in 3 deaths, 7 injuries, and direct economic losses of over 700,000 yuan. The direct cause of the accident was that, when resuming production after maintenance on the photolytic reactor, the operators failed to follow the process requirements by adding an excessive amount of phosgene at a low temperature, resulting in an accumulation of too much phosgene. As the temperature inside the reactor increased, phosgene reacted violently with benzene, raising the pressure inside the reactor. This led to the rupture of the exhaust pipes and leakage of gas; the benzene vapor, which had reached its explosive limit, was ignited by static electricity, resulting in an explosion. The “11•13” explosion at Suanben Plant of Jilin Petrochemical, China National Petroleum Corporation On November 13, 2005, an explosion occurred at the Suanben Plant of Jilin Petrochemical, a subsidiary of China National Petroleum Corporation, resulting in 8 deaths and 60 injuries, including 1 person with severe injuries. The economic loss amounted to 69.08 million yuan. The direct cause of the accident was that the operator at the *** refinement station in the aniline production workshop violated the operating procedures; after stopping the feed of crude ***, they failed to close the steam valve of the preheater, which resulted in the material inside the preheater vaporizing. When resuming production in the *** refining unit, the operating procedures were violated once again: the steam valve of the preheater was opened first to heat the material, and then the crude *** feed pump was started to supply feed. This caused the material entering the preheater to boil violently, resulting in severe vibrations that damaged the flanges of the preheater and pipelines. Air entered the system, forming an explosive mixture; static electricity generated by friction led to an explosion in the distillation tower, which in turn triggered successive explosions in other equipment and facilities. The \"11•14\" toxic gas leak incident at Jinan Huayang Application Technology Co., Ltd. On November 14, 2004, a toxic gas leak occurred at Jinan Huayang Application Technology Co., Ltd., resulting in 3 deaths and 5 people being poisoned, with direct economic losses of around 2 million yuan. The direct cause of the accident was that workers in the 3-mercaptopropionic acid workshop violated the process operating procedures, resulting in an increase in pressure within the system and a massive leakage of hydrogen sulfide. During the evacuation, the operators fainted one after another in the workshop. The personnel on duty in the adjacent workshop noticed this and entered the scene to rescue those who had been poisoned without taking any protective measures, which resulted in more people getting poisoned. The asphyxiation accident at Jiangsu Danhua Group’s Chemical Aditives Factory on \"11•17\" On November 17, 1999, an asphyxiation incident caused by carbon dioxide occurred at Jiangsu Danhua Group’s Chemical Aditives Factory, resulting in 3 deaths and 2 injuries. On the day of the incident, the workshop supervisor led the workers to install a mixer reducer at the inlet of the conversion tank in that factory; at that time, a large amount of lead nitrate, along with carbon dioxide generated during the workshop’s production processes, had already accumulated inside the conversion tank. During the installation work, the workshop supervisor accidentally fell to the bottom of the pool (which was 2.6 meters deep) and lost consciousness. Four workers nearby tried to rescue him without any protective equipment, and they also collapsed at the bottom of the pool one after another, resulting in multiple casualties. The “11•19” deflagration accident at Shandong Xintai United Chemical Co., Ltd. On November 19, 2011, a deflagration accident occurred at Shandong Xintai United Chemical Co., Ltd., resulting in 15 deaths, 4 injuries, and direct economic losses of 18.9 million yuan. During the maintenance of the oil condenser in the urea production workshop at Xintai Chemical, no reliable safety measures were taken to prevent the pressurization water from entering the oil inside the hot gas cooler. As a result, water from the shell side of the oil condenser on the fourth-floor platform flowed into the shell side of the hot gas cooler on the third-floor platform. This water mixed with the high-temperature oil and vaporized rapidly; the water vapor, along with the oil, was ejected through the inlet and outlet flanges of the oil condenser, forming an explosive mixture with air that ignited upon contact with a spark source, leading to an explosion. The “11•20” explosion accident at Shanxi Yushui Chemical Co., Ltd. On November 20, 2010, an explosion occurred at Shanxi Yushui Chemical Co., Ltd., resulting in 4 deaths, 2 severe injuries, and 3 minor injuries, with direct economic losses amounting to 27.25 million yuan. The direct cause of the accident was a crack in the weld at the elbow of the vinyl chloride monomer inlet pipeline at the top of one of the polymerization reactors in Building 2 of the company’s Resin Plant No. 2; the leakage of material led to a deflagration explosion. The \"11•20\" poisoning incident at Xingertai Chemical Co., Ltd. in Zhongwei, Ningxia On November 20, 2012, a carbon monoxide poisoning incident occurred at Xingertai Chemical Company in Zhongwei City, Ningxia, resulting in 4 deaths and 2 injuries. At the time of the incident, the synthesis workshop was adding copper to the regenerator in the refining section; a crane was used to lift the copper sheets into the regenerator. The operator responsible for removing the hook leaned over the manhole of the regenerator to do so, but failed to remove the hook, so he jumped into the regenerator to get it – as a result, he suffered carbon monoxide poisoning and collapsed. Other workers in the workshop entered the regenerator without wearing any protective equipment in an attempt to carry out rescue efforts, which resulted in multiple cases of poisoning and casualties. The extremely serious “11•22” Sinopec Donghuang oil pipeline leakage and explosion accident in Qingdao, Shandong Province: On November 22, 2013, an explosion occurred on the Sinopec Donghuang oil pipeline located in the Qingdao Economic and Technological Development Zone in Shandong Province, resulting in 62 deaths, 136 injuries, and direct economic losses of 750 million yuan. The direct cause of the accident was the rupture of the Donghuang oil pipeline, which crosses at the intersection of Qinhuangdao Road and Zaitangdao Street as well as a drainage trench; corrosion had thinned out the pipeline, leading to an oil spill. The leaked crude oil and gas mixed with air in the underground channel, reaching the explosive limit. When the responders used hydraulic breakers to drill holes in the cover of the channel, the impacts generated sparks that caused the channel to explode. The \"11•23\" poisoning accident at the Yanji Fertilizer Factory in Jilin Province On November 23, 1988, a carbon monoxide poisoning accident occurred at the Fertilizer Factory in Yanji City, Jilin Province, resulting in the death of 16 workers from other companies who were working there. 10 days before the incident, 16 external construction workers were arranged to stay in the offices of the plant’s new gas generation workshop, where self-made heating systems were installed, powered by boilers used for production. In the early hours of the day the incident occurred, the boiler feed pump failed, and during attempts to repair it the steam pressure dropped. Semi-water gas from the conversion system flowed back into the domestic steam system through the steam pipes, and then seeped into the rooms via two leaks in the homemade heating systems in the offices, resulting in the death of all 16 employees due to poisoning. The \"11•24\" LPG tank explosion at the gas filling station on Pusan Road in Shanghai: On November 24, 2007, an explosion occurred in an LPG tank at a gas filling station on Pusan Road in Shanghai, resulting in 4 deaths and 30 injuries. Before the incident, safety inspections at the fueling station revealed potential hazards, leading to its closure for repairs. During the pipeline airtightness test, the pipeline was not separated from the buried liquefied petroleum gas tank using a blind flange; as a result, the liquefied petroleum gas that had not been completely removed from the tank mixed with compressed air, forming an explosive mixture. When exposed to electric welding sparks at the site, this mixture caused an explosion. The \"11•25\" fire accident at Luoding Xinbang Forestry and Chemical Co., Ltd. in Guangdong Province On November 25, 2008, a fire broke out at Xinbang Forestry and Chemical Co., Ltd. in Danbin Town, Luoding City, Yunfu, Guangdong. The accident resulted in 3 deaths and 3 injuries, and all people within a 1-kilometer radius were evacuated. The direct cause of the accident was a sudden leak at the flange of the outlet pipe for the cooling coil in one of the polymerization reactors in the company’s terpene resin workshop during production. The leaked cooling water reacted chemically with aluminum trichloride, which is present in the reactor, generating large amounts of hydrogen chloride gas. This led to a pressure surge, causing a massive release of mixtures including turpentine, toluene, and aluminum trichloride. When these substances came into contact with sources of fire in non-explosion-proof areas such as the packaging workshop and boiler room on the first floor, they caught fire and quickly spread the flames, resulting in an explosion of combustible gases in the resin production and packaging workshops. This in turn triggered a huge fire in the entire terpene resin production workshop. The “11•27” deflagration accident at Jiangsu Lianhua Technology Co., Ltd. On November 27, 2007, a deflagration accident occurred at Jiangsu Lianhua Technology Co., Ltd., resulting in 8 deaths and 5 injuries, with direct economic losses of around 4 million yuan. The direct cause of the accident was improper operation by the operator on duty who handled the dye intermediates; the diazotization reaction should have been kept at a constant temperature, but the heating steam valve was not closed properly, which allowed the reaction vessel to continue heating. As a result, the diazonium salts in the vessel decomposed violently, leading to a chemical explosion. The “11•27” poisoning incident at Heilongjiang Shengnong Technology Development Co., Ltd. On November 27, 2015, an poisoning accident occurred while Heilongjiang Shengnong Technology Development Co., Ltd. was conducting industrial-scale tests of bupirimate using the equipment from the herbicide production facility of Hegang Xuxiang Heyou Chemical Co., Ltd.; as a result, 3 employees of Shengnong Technology Development Co., Ltd. died. The direct cause of the accident was that, during the testing of the new product dimethomorph, the connection pipes between the suction inlets of the exhaust gas negative-pressure absorption and tertiary alkali absorption systems and the exhaust gas froze due to low temperatures, which prevented the alkali absorption tower from functioning properly. As a result, methanethiol in the exhaust gas could not be absorbed in time and leaked out, causing the 3 operators present to be poisoned and die. The “11•28” explosion incident at Zhejiang Linghua Industrial Co., Ltd. On November 28, 2007, an explosion occurred in a secondary acid removal reactor at Zhejiang Linghua Industrial Co., Ltd. in Huzhou City, Zhejiang Province, resulting in 3 deaths. The direct cause of the accident was that the operator on duty in the dimethyl phosphite production unit failed to promptly notice the fault in the methanol feeding system indicated by the DCS control system, as well as the warning signals generated; no effective actions were taken, which led to a failure in the automatic methanol feeding system and an interruption in methanol supply for 2 hours and 40 minutes. This resulted in an excessive amount of phosphorus trichloride being fed into the reactor. The excess phosphorus trichloride entered the crude ester receiver and reacted with the remaining methanol there, producing large amounts of gas (hydrogen chloride, chloromethane) and reaction heat. This caused the lid of the crude ester receiver to be blown off, and the large volume of gas released encountered the sparks generated by the explosion, along with large amounts of phosphorus trichloride coming into contact with water, thereby triggering further explosions and fires. Explosions and fires produce large amounts of irritating gases, causing workers on site to suffocate while trying to escape. The \"11•28\" liquid ammonia leak accident at Longgang Chemical Co., Ltd. in Handan, Hebei Province On November 28, 2015, a liquid ammonia leak occurred at Longgang Chemical Co., Ltd. in Handan City, Hebei Province, resulting in 3 deaths and 4 injuries. At the time of the incident, workers were filling a tank truck with liquid ammonia from a storage tank; a leak at the flange blind plate of the backup liquid ammonia feed line resulted in the death of 2 operators and 1 tank truck driver, as well as injuries to 4 people. (II) Foreign accidents: The “11•6” explosion at an oil chemical plant in India. On November 6, 1990, an explosion and fire broke out at the plant of the state-owned Indian Oil Chemicals Corporation in Maharashtra, located 160 kilometers south of Mumbai, India; the incident resulted in 21 deaths and 20 severe injuries. The direct cause of the accident was a leak in the pipeline supplying ethane and propane gases to the gas cracking complex equipment, which led to an explosion in the gas purification and compression equipment and triggered a large fire. The “11•9” Tank Farm Explosion at the Mavro Refinery in India: On November 9, 1988, an explosion occurred at the tank farm of the Mavro Refinery located near Mumbai, India. The accident resulted in 22 deaths, 12 people suffering serious injuries, and 15 people with minor injuries; the direct economic loss amounted to 140 million yuan. The direct cause of the accident was a rupture in the naphtha pipeline in the storage tank area, which led to a massive leak of naphtha and the formation of an oil-gas mixture. When this mixture came into contact with an open flame, an explosion occurred. As a result of this explosion, 3 naphtha storage tanks, 2 benzene storage tanks, and numerous pipelines were damaged. The shock wave from the explosion reached a radius of 5 kilometers, and the resulting fire burned for 28 hours. The “11•19” explosion at a liquefied petroleum gas supply station in Mexico: On November 19, 1984, an explosion occurred in a liquefied petroleum gas storage tank at a supply center owned by a petroleum company located near Mexico City. The accident resulted in 542 deaths, over 7,000 injuries, and 350,000 people left without homes. On the day of the incident, an explosion first occurred at the nearby Univas Gas Company while filling a liquefied petroleum gas tank truck. Subsequently, due to a leak in the gas pipelines, the fire caused by the explosion ignited 54 liquefied petroleum gas storage tanks at the Mexican Petroleum Company’s supply station, leading to a series of explosions. The fire lasted for over seven hours before it was extinguished, and more than 1,400 residential buildings in the vicinity were damaged.