Typical hazardous chemical accidents that occurred in July throughout history

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1.jpg I. Typical accidents in June 2016 1. The “6•5” poisoning and asphyxiation accident at Weifang Huahao Agrochemical Company in Shandong Province On June 5, 2016, a poisoning and asphyxiation accident occurred in the water-soluble fertilizer production workshop of Weifang Huahao Agrochemical Co., Ltd. in Weicheng District, Weifang City, Shandong Province, resulting in 3 deaths. At around 2 p.m. on June 5, operator Rong turned on the feeding pump and found that the amino acid concentrate could not be drawn out of the raw material tank. He then climbed onto the top of the tank to check the situation inside using a manhole, and measured the liquid level inside with a bamboo pole. Subsequently, packager Li noticed that Rong was lying half in the tank and called for help. Upon hearing the cries for help, two workers entered the tank without wearing any protective gear to carry out the rescue; they subsequently fell to the bottom of the tank. By the time the firefighters rescued the three people from the tank, they were already dead. Preliminary analysis indicates that the direct cause of the accident was as follows: Rong failed to conduct tests on oxygen and toxic gas concentrations, did not wear any personal protective equipment, and recklessly entered the tank. As a result of oxygen deficiency and excessive carbon monoxide levels inside the tank, he suffered from poisoning and suffocation ； The other two workers, without wearing personal protective equipment, entered the tank blindly to carry out rescue efforts and subsequently suffered from poisoning and asphyxiation, which led to an escalation of the accident’s consequences. 2. The “6•12” poisoning incident at Tianshui Lixin Petrochemical Company in Gansu Province On June 12, 2016, a poisoning incident occurred at Tianshui Lixin Petrochemical Co., Ltd. in Maiji District, Tianshui City, Gansu Province, resulting in 3 deaths and 1 injury. At around 9:30 a.m. on June 12, while working on the top of Mixing Tank No. 3, Li and Zhang, employees of Lixin Company, accidentally dropped their gloves through an observation hole on the tank’s surface into the tank. The two then entered the tank one after the other to retrieve the gloves and render assistance. Jia, the legal representative of Lixin Company, noticed that two people were missing. He sent people to search for them, and they were found lying at the bottom of the tank. Consequently, two other employees were dispatched into the tank to rescue them; however, they also suffered from poisoning. After being rescued by firefighters, it was confirmed that 3 people died and 1 person was injured. Preliminary analysis indicates that the direct cause of the accident was as follows: during the process of heating and melting asphalt in the mixing tank and adding various additives, toxic and harmful gases accumulated inside the tank. Two workers entered the tank and were poisoned; subsequent reckless rescue attempts led to the escalation of the accident. The exact reasons are still under investigation. 3. The “6•15” fire accident at Shijiazhuang Refining & Chemical Plant in Hebei On June 15, 2016, a fire broke out in the absorption tower of the flue gas desulfurization and denitrification system at Sinopec’s Shijiazhuang Refining & Chemical Plant’s 2.2 million tons per year catalytic cracking unit, resulting in 4 deaths. In April 2016, Shijiazhuang Refining & Chemical discovered severe corrosion on the walls of the desulfurization tower, and thus commissioned Sinopec No. 10 Construction Company to carry out repairs. At 9:00 on June 15, after the gas analysis inside the tower proved satisfactory and they obtained permits for working in a confined space and hot work, four workers from Sinopec’s Tenth Construction Company entered the desulfurization tower to perform repair welding on its chimney section. At 10:24, the supervisor noticed smoke coming from the manhole at the lower part of the cone section of the desulfurization tower, and immediately called the company’s emergency services. After putting out the fire, the rescue team arrived and found that 4 workers had died. Preliminary analysis indicates that the direct cause of the accident was that, during the anti-corrosion welding work on the top of the chimney, the falling welding slag caused the polypropylene-based demister to catch fire; hot smoke was then discharged through the chimney, leading to the death of the workers due to heat exposure and asphyxiation from toxic fumes ； The detailed cause of the accident is currently under investigation. II. Historical accidents involving hazardous chemicals that occurred in July
The “July 1” explosion of a methylamine storage tank at Ningxia Ruitai Technology Co., Ltd.
On July 1, 2014, an explosion occurred in a storage tank containing N-(6-chloro-3-pyridylmethyl)methylamine in the acetamiprid production workshop of Ningxia Ruitai Technology Co., Ltd. The incident resulted in 4 deaths and 1 injury; the direct economic loss amounted to approximately 5 million yuan. The reason is that N-(6-chloro-3-pyridinemethyl)methanamine in the storage tank remained at a constant temperature for an extended period, resulting in a polycondensation reaction; the large amount of heat and gas generated could not be discharged in time, which led to overpressure in the container and an explosion. The \"7·2\" oil tank explosion accident at Weifang Hongrun Petrochemical Additives Factory in Qingzhou, Shandong Province On July 2, 2000, two 500-cubic-meter oil tanks at Weifang Hongrun Petrochemical Additives Factory in Qingzhou, Shandong Province, exploded and caught fire, resulting in 10 deaths and direct economic losses of over 2 million yuan. The cause of the accident was that, during the hot work, valves were closed instead of blind flanges being installed; the area where the hot work was carried out was not properly isolated from the production system. The explosive gas mixture inside the tank leaked into the pipe that was being welded, and the electric arc from the welding caused the gas in the pipe to explode, which in turn led to an explosion of the gas mixture inside the oil tank. The \"7·3\" acetylene tank explosion at the chemical plant in Chun’an County, Zhejiang Province On July 3, 1987, an explosion occurred at a chemical plant in Chun’an County, Zhejiang Province, while work was being carried out on an acetylene tank, resulting in 3 deaths. The reason is that the calcium carbide slag in the gas tank was not cleaned properly; the manhole cover of the gas tank was not opened during welding, resulting in acetylene gas generated by the calcium carbide slag, and no sampling analysis was conducted before starting the welding work. The \"7·4\" liquid chlorine cylinder explosion at Chengdu Chemical Plant in Sichuan Province On July 4, 1995, a cylinder used for storing liquid chlorine at Chengdu Chemical Plant in Sichuan Province exploded, resulting in 3 deaths and 6 injuries. The cause of the accident was a failure to conduct proper inspections during the liquid chlorine filling process; paraffin remained inside the cylinder. When liquid chlorine entered the cylinder, it reacted violently with the paraffin, resulting in an explosion. The \"7·4\" poisoning incident at Tianxiang Building Materials and Chemicals Co., Ltd. in Baiyin, Gansu On July 4, 2010, a poisoning incident occurred at the zinc carbonate factory of Tianxiang Building Materials and Chemicals Co., Ltd. in Baiyin District, Baiyin City, Gansu, resulting in 3 deaths and 3 injuries. Ammonia was generated as a result of the reaction between ammonium bicarbonate and zinc oxide in the reaction tank; workers entered the tank in violation of safety regulations, which led to poisoning and unconsciousness. The rescuers lacked sufficient emergency response knowledge, contributing to the escalation of the accident. The “7·7” explosion in the chlorobenzene recovery tower at Yunnan Qujing Zhongyi Synthetic Chemicals on July 7, 2014: On that day, an explosion occurred in the chlorobenzene recovery system of Workshop 1 in Plant 1 of Yunnan Qujing Zhongyi Synthetic Chemicals Co., Ltd., resulting in 3 deaths, 4 injuries, and direct economic losses of 5.6 million yuan. Direct causes of the accident: First, there was an internal leak in the AO-heat transfer oil heat exchanger at the bottom of the chlorobenzene recovery tower. The high-temperature heat transfer oil from the tube side leaked into the shell side, where it mixed with residual chlorobenzene liquid. This mixture then entered the chlorobenzene recovery tower, causing its temperature to rise. Consequently, the vapor pressure of the residual liquid increased dramatically, leading to an explosion and fire in the chlorobenzene recovery tower ； Secondly, the temperature control valve was not installed as required by the design; only a locally operated \"stop valve\" was installed. When the temperature and pressure at the bottom of the recovery tower deviated from the normal range of process parameters, the \"stop valve\" was unable to carry out automatic adjustments or timely regulation. The \"7·8\" gas poisoning accident at the chemical plant in Suining County, Sichuan Province On July 8, 1984, a gas poisoning accident occurred at the chemical plant in Suining County, Sichuan Province, resulting in 3 deaths and 1 injury. At the time of the incident, 4 workers entered the conversion furnace to remove old catalysts; since a blind flange was not used to cut off the gas supply, gas flowed back from the scrubber tower into the conversion furnace, causing the workers to be poisoned. The workers failed to obtain a \"Permit for Working in Confined Spaces,\" failed to implement the necessary safety measures, the purging time for harmful gases in the converter was insufficient, and they entered the toxic and hazardous confined spaces without wearing gas masks. The on-site workers lacked knowledge of emergency procedures, and their reckless attempts at rescue led to the death of the rescuers, thereby exacerbating the accident. The “July 11” explosion at Shandong Deqilong Chemical Group Co., Ltd. On July 11, 2007, an explosion occurred at Plant No. 1 of Shandong Deqilong Chemical Group Co., Ltd. during the trial operation of a renovation and expansion project, resulting in 9 deaths and 1 injury. This explosion was a physical explosion; the direct cause of the incident was the insufficient strength of the compressor outlet pipeline, poor welding quality, and the failure to conduct pressure testing on the pipeline before its use. The \"7·12\" tank fire accident at Heilongjiang Chemical Plant: On July 12, 1994, the roof of a tank in the tar processing area of Heilongjiang Chemical Plant ruptured, causing the stored material to spill out and catch fire, resulting in 3 deaths. The reason was the lack of strict control over the temperature of the tar and anthracene oil mixture being injected; the high temperature of this mixture caused an increased amount of vaporization, which led to the tearing of the tank roof and resulted in hot oil spraying out and causing a fire. The \"7·14\" poisoning accident at Runfangte Oil Co., Ltd. in Luoyang, Henan Province On July 14, 2007, Runfangte Oil Co., Ltd. in Luoyang, Henan Province, suffered a poisoning accident while cleaning the residues at the bottom of a storage tank; this incident resulted in 3 deaths and 1 person suffering serious injuries. The cause of the accident was that the workers violated operating procedures by failing to analyze and test the gases inside the tank, failing to take any safety precautions, and entering the storage tank to carry out work directly ； The rescuers carried out their efforts blindly without taking any safety precautions, which led to the accident from worsening. The “7·15” explosion at Luoyang Luoyan Co., Ltd. in Henan Province On July 15, 2009, an explosion occurred in Workshop 1 of Luoyang Luoyan Co., Ltd. in Henan Province, resulting in 8 deaths and 8 injuries. The cause of the accident was the chlorobenzene vapor emitted from the chlorobenzene metering tank at the neutralization and extraction site; this vapor encountered a source of fire in the nearby power cables that had short-circuited due to aging, resulting in an explosion of the chlorobenzene vapor. The chlorobenzene metering tank was set on fire, which led to an explosion. This in turn caused the finished product, 2,4-dichlorobenzene, in the washing tank to explode for the first time, and subsequently triggered a second explosion of 2,4-dichlorobenzene in the nitration tank. The “7·16” oil pipeline explosion and fire incident at Dalian CNPC International Storage and Transportation Co., Ltd. On July 16, 2010, an explosion occurred in the oil pipeline of the crude oil tank farm operated by Dalian CNPC International Storage and Transportation Co., Ltd., resulting in a large-scale leakage of crude oil and a fire. The crude oil flowed into the nearby waters, causing environmental pollution. The accident also resulted in 1 worker going missing, and 1 firefighter lost their life during the firefighting efforts. The direct cause of the accident was that, with the oil tanker’s unloading operations suspended, a large amount of hydrogen sulfide scavenger (containing 85% hydrogen peroxide) was continued to be added, resulting in a local accumulation of hydrogen peroxide in the oil pipeline section near the addition point ； The high concentration of hydrogen peroxide in the oil pipeline reacts exothermically upon contact with crude oil and water, causing the pipeline to explode, leading to a crude oil spill and a fire. The \"7·16\" heat exchanger fire accident at CNPC Dalian Petrochemical Company: On July 16, 2011, a fire broke out due to a leak at the seal of the heat exchanger tube bank in the third distillation unit of the Dalian Petrochemical production area in Liaoning Province. The accident resulted in direct economic losses of 1.878 million yuan, with no casualties reported. The direct cause of the accident was that the material of the flange gasket did not meet the relevant technical standards; the thickness of the gasket was insufficient, failing to reach the required 4.5 millimeters. During installation, the gasket was misaligned and the bolts were not tightened evenly, which led to damage to the gasket and the release of crude oil. The leaked crude oil flowed onto the high-temperature surface of the heat exchanger located below the point of leakage (the temperature of the fluid in the second-stage heat exchanger was around 350°C), where it caught fire. The \"7·16\" explosion incident at Shandong Shida Technology Petrochemical Co., Ltd. in Rizhao City, Shandong Province: On July 16, 2015, a leak and fire occurred in the liquefied hydrocarbon storage tank of Shandong Shida Technology Petrochemical Co., Ltd. during a transfer operation, which led to an explosion. As a result, 2 firefighters were lightly injured, and the direct economic loss amounted to 28.12 million yuan. The direct cause of the accident was that, during the tank transfer operation, the company illegally used water injection to replace the contents of the tank; moreover, no one was on site during the water drainage process. As a result, liquefied petroleum gas leaked out from the drainage outlet after the water was drained. Static electricity generated during the leakage, or sparks resulting from the violent movement of fire hoses and the impact of metal connectors and binding wires against equipment or pipes, led to an explosion. The “July 17” explosion of a toluene tank at Xiamen Electrochemical Plant in Fujian Province On July 17, 1989, an explosion occurred at the saccharin workshop of Xiamen Electrochemical Plant in Fujian Province during welding work on the top of an empty benzene storage tank. The incident resulted in 3 deaths and 2 people suffering serious injuries. The direct cause of the accident was the connection between the storage tank and the production system; it was not properly isolated from the production system as required before welding, which allowed materials to flow into the tank where welding was taking place and triggered an explosion. The \"7·18\" high-pressure pipe explosion accident in the ammonia synthesis system of Yuishi Chemical Plant in Henan Province: On July 18, 1997, an explosion occurred during an air test of the north synthesis system at Yuishi Chemical Plant in Henan Province, resulting in 4 deaths and 56 injuries. At the time of the incident, the company was testing the compressor using air while it was in operation; the valves connecting the compressor, which was being tested with air, to the production system were not isolated with blind flanges, allowing semi-water gas to enter the system and causing explosions in the methanol cooling unit, as well as in the first and second alcohol separators and high-pressure pipelines. The “July 21” explosion at the Fengxian Fertilizer Plant in Jiangsu Province: On July 21, 1990, an explosion occurred at the Fengxian Fertilizer Plant in Jiangsu Province while workers were replacing the cover of a concentrated ammonia storage tank. The incident resulted in the deaths of three workers. The direct cause of the accident was that the concentrated ammonia storage tank and the lower dilute ammonia storage tank were connected vertically, separated only by a steel plate in between. When replacing the top cover, only the concentrated ammonia storage tank was isolated and its contents replaced; the system did not stop operating, and the lower dilute ammonia storage tank continued to function. The breathing port of the dilute ammonia storage tank was not covered; with the port open, explosive gases were formed, and welding sparks falling caused the dilute ammonia storage tank to explode. The \"7·21\" poisoning accident at Gansu Jinshi Chemical Co., Ltd. On July 21, 2013, a carbon monoxide poisoning incident occurred in the caustic soda production workshop of Gansu Jinshi Chemical Co., Ltd., resulting in 4 deaths and 4 injuries, with direct economic losses of around 3.67 million yuan. The direct cause of the accident was the tripping of the frequency converter of the exhaust fan during the operation of the dryer, resulting in insufficient exhaust volume. This led to incomplete combustion of the coal powder inside the dryer, thereby generating toxic and harmful gases such as carbon monoxide. These gases flowed back into the maintenance pit on the lower floor through the casing of the elevator, causing high concentrations of such toxic and harmful gases in the pit. The operators entered the pit to clean up the ash without any protective measures, which led to their poisoning. The \"7·22\" explosion caused by molten calcium carbide coming into contact with water at the calcium carbide factory in Hanzhong City, Shaanxi Province On July 22, 1989, an explosion occurred at a calcium carbide factory in Hanzhong City, Shaanxi Province, due to molten calcium carbide coming into contact with water; this incident resulted in 4 deaths and 2 severe injuries. The direct cause of the accident was the presence of a large area of standing water at the scene. When reversing, there was no one directing the calcium carbide pot trucks. At a distance of 1.8 meters from the rope distributor, a knot in the steel wire rope came loose automatically upon encountering a guide wheel, causing a shift in the direction of the pulling force. As a result, one of the calcium carbide pot trucks derailed and overturned. After overturning, the molten red calcium carbide exploded upon contact with water. The “July 22” chlorine gas leak accident at Liaoning Jinxi General Chemical Plant On July 22, 1995, a chlorine gas leak occurred at the railcar loading area in the liquid chlorine workshop of the chlor-alkali plant under Liaoning Jinxi General Chemical Plant. The incident resulted in 1 death, 11 people suffering from acute chlorine poisoning, and 45 others experiencing varying degrees of irritation due to chlorine exposure. The reason was that the displacement of the railway tank car caused the connection pipeline between the chlorine valve on the top of the tank car and the chlorine production valve located in the cargo area to break, resulting in the liquid chlorine inside the tank car leaking out. The “7·22” pipeline leak and explosion at Guizhou Xingyi Yihua Chemical: On July 22, 2010, an explosion occurred in the shift conversion section of Guizhou Yihua Chemical Co., Ltd., resulting in 8 deaths and 3 injuries. The reason was a leak in the auxiliary pipeline of the 1# conversion system; the gas flowing through this pipeline generated static electricity, which ignited the flammable gases present on site (mainly carbon monoxide, carbon dioxide, hydrogen, etc.), resulting in an explosion in that area. The “7·23” explosion at the Shangcheng Road gas station of Henan Zhengzhou Standard Petrochemical Co., Ltd. On July 23, 2001, an explosion occurred at the Shangcheng Road gas station belonging to Henan Zhengzhou Standard Petrochemical Co., Ltd., resulting in 4 deaths and 12 injuries. The direct cause of the accident was a leak in the circumferential weld of the oil transfer vertical pipe beneath the fuel pump at the gas station; this leak allowed oil to seep into the basement, where it mixed with large amounts of air, resulting in a mixture that reached its explosive limit. Since the equipment in the basement is of the ordinary, non-explosion-proof type, electric sparks are generated when operators enter the basement to operate the light switches, which leads to an explosion. The \"7·24\" chlorine leak accident at Guangyi Chemical Factory in Qingdao, Shandong Province On July 24, 1997, a chlorine leak occurred at Guangyi Chemical Factory in Qingdao, Shandong Province, resulting in more than 1,900 people inhaling chlorine gas; 24 of them suffered mild to moderate poisoning. The reason is that the liquid chlorine storage tank suffered from severe corrosion; rust at the junction between the edge of the upper walkway and the tank body led to a rupture, resulting in a leak of chlorine gas from the tank. The “7·26” explosion at Hudaibei Fine Chemical Factory in Wuxi, Jiangsu Province On July 26, 2005, an explosion occurred in the dicyclopentadiene cracking reactor at Hudaibei Fine Chemical Factory in Wuxi City, Jiangsu Province, during the pilot production of hexachlorocyclopentadiene. The accident resulted in 9 deaths and 3 injuries. The direct cause of the accident was that, during the cracking reaction stage of the hexachlorocyclopentadiene production process, due to serious defects in the manufacturing quality of the dicyclopentadiene cracker, the fillet weld connecting the lower tube sheet to the shell flange cracked, allowing the heating medium of the cracker – molten salt – to flow into the dicyclopentadiene cracking vessel. The molten salt contains 55% potassium nitrate, a strong oxidizing agent, which undergoes violent chemical reactions with organic substances such as dicyclopentadiene in the pyrolysis vessel, resulting in an explosion of the vessel. The \"7·26\" leak and fire incident at the atmospheric pressure unit of CNPC Qingyang Petrochemical Branch: On July 26, 2015, a leak and fire occurred in the residue/oil crude oil heat exchanger at CNPC Qingyang Petrochemical Company, resulting in 3 deaths and 4 injuries. The direct cause of the accident was an incorrect installation of the plug at the drainage port on the outer cover of the residue/oil heat exchanger in the atmospheric-pressure unit during maintenance; this led to the plug falling off under high temperature and pressure. High-temperature residue at around 342°C–346°C (with a self-ignition temperature of 240°C) was ejected instantly, ignited upon contact with air, and this triggered the fire. The \"7·27\" poisoning accident at Suote Salt Chemical Plant in Wanzhou, Chongqing On July 27, 2007, an asphyxiation accident occurred at the Suote Salt Chemical Plant in Wanzhou District, Chongqing, resulting in 5 deaths. At the time of the incident, 5 workers were carrying out anti-corrosion treatment on an idle tank that had previously stored sodium chlorate electrolyte. The sodium chlorate caught fire, releasing toxic gases that caused the 5 workers to suffer burns and die from asphyxiation. The “7•28” explosion in the chlorination tower at the Linhai branch of Yancheng Fluorine Source Chemical Co., Ltd. in Sheyang County, Yancheng City, Jiangsu Province On July 28, 2006, an explosion occurred in the chlorination reaction tower in Building No. 1 of the Linhai branch of Yancheng Fluorine Source Chemical Co., Ltd. in Sheyang County, Yancheng City, Jiangsu Province, resulting in 22 deaths, 3 serious injuries, and 26 minor injuries. The direct cause of the accident was that, with no cooling water in the condenser of the chlorination reactor and no product flow at the top of the tower, the operation was not stopped immediately; instead, heating was continued erroneously, keeping the material (2,4-***fluorobenzene) at high temperatures for an extended period, which ultimately led to its decomposition and explosion. The “7·28” underground propylene pipeline leak and explosion accident in Nanjing, Jiangsu On July 28, 2010, an explosion involving propylene occurred in Qixia District, Nanjing City, Jiangsu Province, resulting in 22 deaths and 120 injuries. The direct cause of the accident was that, during the land leveling and demolition work at the former site of the plastic factory, an excavator punctured an underground propylene pipeline, resulting in the leakage of liquid propylene from the pipeline. Once the leaked propylene evaporated and dispersed, it came into contact with an open flame, triggering an explosion. The “7·30” explosion in the pure methanol metering tank at Shandong Ruixing Chemical Group: On July 30, 1996, an explosion occurred in the urotropine production workshop of the organic chemicals factory belonging to Shandong Ruixing Chemical Group, resulting in 9 deaths and 5 serious injuries. At the time of the incident, the workers were welding the overflow pipe of the pure methanol metering tank. This overflow pipe was connected to the upper part of the metering tank, but no blind plate was in place. The feed valve at the bottom of the feed pipe was removed, allowing the methanol vapor inside the tank to mix with the air at the open feed end, thus forming explosive gases. The welding sparks ignited these mixed gases, resulting in an explosion. The “7·31” condensed oil leakage and asphyxiation accident at Cangzhou Refinery in Hebei Province: On July 31, 1998, an asphyxiation accident occurred while the engineering team at Cangzhou Refinery in Hebei Province was performing maintenance on the condensed oil pump of a catalytic unit, resulting in 4 deaths. At that time, the catalytic unit was undergoing a temporary shutdown for maintenance. The workers performing the repairs failed to check and verify the closed status of the valves as required before starting the work. Since the inlet and outlet valves of the condensate oil pump were not closed, the material did not get completely drained, resulting in the spraying of condensate oil. This created a thick white mist inside the enclosed pump room, leading to an asphyxiation accident. The \"7·31\" pipeline leakage and explosion incident at Hua Yun Warehousing Company in Kaohsiung, Taiwan On July 31, 2014, a leak of propylene occurred in the propylene transport pipeline at Hua Yun Warehousing Company in Kaohsiung City, Taiwan. At midnight on August 1, an explosion of propylene gas in a sewer occurred, resulting in 30 deaths and 302 injuries. The direct cause of the accident was that the pipeline had thinned over the years due to corrosion by rainwater; under pressure, it ruptured, resulting in the leakage of propylene, which exploded upon contact with an ignition source.