NOTE: the text below is a translation from Chinese to English
At about 13:49 on May 3, 2018, a catalyst explosion occurred in the hydrogenation reactor of No. 1 hydrogenation reactor of a Pharmaceutical facility causing one death and an immediate economic loss of 1.446 million yuan ($216,061,320 USD). According to the “Safety Production Law of the People’s Republic of China”, the bureau led the establishment of an accident investigation team composed of the Municipal Public Security Bureau and the General Labor Union. At the same time, the People’s Procuratorate of Taizhou City was invited to send personnel to participate in the investigation. The accident investigation team entrusted a professional appraisal agency to identify the accident material certificate and hired three experts to form an expert group to analyze the cause of the accident.
In accordance with the principles of “scientific and rigorous, legally compliant, seeking truth from facts, and paying attention to practical results”, the investigation team found out the cause of the accident through on-site investigation, investigation and evidence collection, expert argumentation and comprehensive analysis. In the case of casualties and direct economic losses, the nature and responsibilities of the accident were identified, suggestions for handling the responsible persons and responsible units were put forward, and suggestions for accident prevention and rectification measures were proposed. The relevant situation is reported as follows:
First, the basic situation:
- The situation of the accident unit (omitted)
- Process and site inspection
The main products of Yangzi Medicine are p-nitrophenol and p-aminophenol. The production process is as follows:
p-nitrophenyl chloride is used as raw material to form sodium p-nitrophenolate (intermediate product) by hydrolysis, and then acidified by hydrochloric acid to produce sodium nitrate.
Phenol; using p-nitrophenol as raw material, Raney nickel (in the case of spontaneous combustion of air, generally immersed in water or ethanol solution for storage) as a catalyst, hydrogenation reaction, reduction to produce p-aminophenol.
After on-site inspection, the accident occurred in the hydrogenation plant Phase 1 p-aminophenol production line No. 1 hydrogenation kettle, located on the west side of the hydrogenation station platform on the second floor of the workshop. The residual material in the No. 1 hydrogenation kettle was extracted on site and identified as a mixture of a certain concentration of ethanol solution and Raney nickel.
Second, the accident and emergency response:
(1) The accident occurred
On May 2, 2018, Yangzi Medicine prepared to shut down the whole factory for maintenance. Hydrogenation Phase 1 No. 1 hydrogenation reactor was completed at 0:53 on May 3, after standing and pressing operations, and two ethanol washing operations were carried out. At 5:44, tap water (about 200 liters) and start stirring until the accident occurred.
On the afternoon of May 3, the deputy director of the hydrogenation workshop, arranged the operation of the No. 1 hydrogenation reactor. At 13:41, the manhole of No. 1 hydrogenator was opened. He then gradually opened the vacuum valve on the kettle three times, causing a large amount of air to be sucked into the No. 1 hydrogenation reactor to form an explosive mixed gas with the ethanol vapor in the kettle. Then he went to the mouth of the kettle, and rinsed the paddles of the No. 1 hydrogenator and the residual catalyst on the wall. During the rinsing process, the No. 1 hydrogenation kettle flashed, and he was “bumped” by the explosion shock wave.
(2) Emergency disposal situation
Immediately after the accident, the site personnel dialed the “110” and “120” calls. After the “120” car doctor on-site inspection confirmed that Wang had died.
(3) Casualties and direct economic losses
1. Casualties: One person was killed in the accident
2. Direct economy caused by the accident: The direct economic loss caused by the accident was 1.446 million yuan ($216,061,320 USD)
Third, the cause and nature of the accident
(1) The direct cause of the accident
Worker violated the regulations. In the state where the manhole of No. 1 hydrogenator was opened, it was not filled with nitrogen gas protection, but the vacuum pump was turned on, causing a large amount of air to be sucked into the reaction vessel to form an explosive mixed gas with ethanol vapor, and the catalyst Raney nickel was exposed to air. Spontaneous combustion, causing flash explosion, is the direct cause of the accident.
(2) Indirect causes of accidents
1. Post operation procedures are not perfect
Yangzi Medicine does not have a separate safety operation procedure for the withdrawal of catalyst (Rani Nickel). Only in the operation of the essential card, the principle should stipulate that the tank should be filled with nitrogen after opening. The provisions on the precautionary measures for accident risk of Raney nickel in the process of catalyst withdrawal are not strict or unclear.
2. The operation approval is in the form
The enterprise overhaul workshop is not strict with the examination and approval of inspection and maintenance operations. The implementation of the isolation air measures is not confirmed on the spot, and the inspection and maintenance work tickets are issued at will; the safety risk is identified on the site by the mechanics, risk prevention and control measures are formulated, and the enterprise safety supervision measures are not in place.
3. The relevant personnel are not in position
The relevant person in charge of Yangzi Medicine, the person in charge of production, and other relevant management personnel did not perform their safety management duties effectively. The investigation and management of safety hazards and the safety education and training of employees were not in place. The employees violated regulations and were not stopped and corrected in time, and buried accidents. .
(3) Nature of the accident
According to the investigation, the “5.3” flash explosion accident of Taixing Yangzi Pharmaceutical Chemical Co., Ltd. is a production safety accident.
4. Identification of accident liability and suggestions for handling personnel and units responsible for accidents
(1) The person responsible for the accident and the handling suggestions
1. Wang Moumou, deputy director of the hydrogenation workshop, in the process of withdrawing the catalyst from the hydrogenation reactor, is responsible for the accident and is responsible for the accident. In view of the death in the accident, it is recommended not to pursue it.
2. Qian Moumou, director of the machine repair workshop of Taixing Yangzi Pharmaceutical Chemical Co., Ltd., did not confirm the implementation of the air-insulated measures on the spot, issued a maintenance and repair work ticket, and was responsible for the accident. It is recommended that Yangzi Pharmaceutical should handle it according to the company’s relevant rules and regulations.
3. Su Moumou, deputy general manager of Taixing Yangzi Pharmaceutical Chemical Co., Ltd., responsible for the daily production management of the company. Failure to conduct risk analysis on production operations and formulate corresponding operational procedures shall be responsible for the occurrence of accidents. It is recommended that Yangzi Pharmaceutical shall handle the matter in accordance with the relevant rules and regulations of the company.
4. Ren Moumou, general manager of Taixing Yangzi Pharmaceutical Chemical Co., Ltd., as the main person in charge of the enterprise, did not organize relevant personnel to establish sound safety operation procedures, did not effectively implement the safety education and training work of the unit, and was responsible for the occurrence of the accident. It is recommended that the Taizhou Municipal Safety Supervision Bureau impose a fine of 30% of the annual income of 2017 in accordance with the provisions of Item (1) of Article 92 of the Law of the People’s Republic of China on Safe Production.
(2) Accident responsible units and handling suggestions
Yangzi Medicine, employee safety education and training is not in place, failing to urge employees to seriously implement the catalyst removal operation points, the risk analysis of the accidents of catalyst withdrawal is not in place, and it is responsible for the occurrence of the accident. It is recommended that the Taizhou Municipal Safety Supervision Bureau should rely on the “Chinese people”. Article 119 (1) of the Republic’s Safe Production Law provides a fine of RMB 350,000 to Yangzi Medicine.
V. Suggestions for accident prevention and rectification measures
(1) Yangzi Medicine should profoundly learn from the accident, establish a safety production management system in which the safety director and the special safety management organization are directly responsible to the general manager; re-establish the safety production rules and regulations and operating procedures for the approval of catalyst removal; Do a good job in safety production education and training for operators, improve the safety awareness and operational skills of operators; standardize the operation approval process, strictly implement various safety precautions to ensure safe operation. At the same time, Yangzi Medicine should re-inspect the safety design of the production facilities of the whole plant and carry out safety risk assessment of fine chemical reactions to ensure the production process is safe and reliable.
(2) The management committee of Taixing Economic Development Zone shall supervise and urge enterprises in the park to earnestly absorb the lessons of accidents, earnestly fulfill the responsibility of local supervision of safe production, increase the safety supervision of dangerous chemical enterprises within their jurisdiction, and increase the supervision and promotion of hidden dangers to prevent similarities. The accident happened again.
(3) Taixing Municipal Safety Production Supervision Administration shall organize accident warning education within the city, urge the city’s chemical enterprises to seriously absorb the accident lessons, urge chemical enterprises to regularly edit safety production management systems and operational procedures, and urge enterprises to strengthen staff positions. Safety Training.