Production Technology [Weekly Topic]: Accident Analysis (10-12-6~12-12)

1. Direct cause: Nitrogen was used instead of air to purge and replace the oil tank; no analysis was conducted, no permits were obtained, and no protective equipment was worn； Indirect causes: inadequate management, insufficient training, and weak safety awareness. 2. Using nitrogen in place of air ； 2. No analysis was conducted before entering the tank, no permits were obtained, and no protective equipment was worn ； Blindly attempting rescue. 3. Strengthen training on safety production knowledge, enforce the implementation of various safety regulations and systems, and ensure strict management of tickets and certificates.

1. Direct cause: The operator violated regulations by failing to obtain a work permit, failing to check the oxygen level, and failing to designate a safety officer； 2. Indirect causes: The factory has chaotic safety management practices, a lack of safety supervisors on site, and poor enforcement of regulations ； Unclear pipeline identification leads to misoperations by operators. 3. Violation: Failure to obtain a work permit ； Oxygen content not detected ； Unlearned* Assignment Measures ； Working without safety supervisors present. 4. Preventive measures: Strict management of various systems ； Strengthen safety supervision ； Strengthen training ； Improve the labels in accordance with standards.

Immediate cause: 1. Operator error – failure to distinguish between the nitrogen pipeline and the air pipeline； 2. Entering a confined space without obtaining a work permit ； 3. Attempting to rescue someone blindly poses significant risks. Indirect causes: 1. The nitrogen pipeline and the air pipeline should not have any obvious markings or color codes ； 2. Entering confined spaces should be considered *routine work; there is a lack of safety awareness, and there are also issues with daily supervision

Immediate cause: Incorrect use of nitrogen displacement, resulting in a lack of oxygen inside the tank. Indirect causes: An oxygen content analysis was not conducted, the necessary procedures were not followed, and the guardians failed to take appropriate rescue measures. First, use air for displacement, then conduct an oxygen level analysis; obtain the necessary permits from the relevant authorities for entering the tank, assign appropriate supervisors, and put in place rescue measures.

1. Direct cause: a. Operational error: nitrogen was used for purging instead of plant air. b. No permit for working in a confined space was obtained, oxygen levels and concentrations of toxic gases were not checked on schedule during the operation, and the environmental conditions inside the tank were unknown. c. The workers were not wearing protective equipment. d. Ventilation inside the tank was not considered during the operation, resulting in a poor working environment within the tank. 2. Indirect causes: a. Low safety awareness among personnel involved in related tasks and certificate processing. b. Safety measures were not arranged simultaneously when assigning personnel to carry out tasks. 3. Preventive measures: a. When scheduling tasks, it is necessary to analyze and predict the risks associated with those tasks in accordance with the requirements of safety standardization, and to implement reliable countermeasures to ensure comprehensive, round-the-clock, and full-process safety management. b. Strictly implement relevant operating procedures, standardize the processing procedures for related work permits, and rigorously control the approval process for such permits. c. Strengthen safety training for employees, raise their safety awareness and self-protection consciousness, and ensure they wear protective equipment properly.

A chemical plant was carrying out cleaning work on train tank cars, and during the operation, workers Wang, Liu, Zhao, and Jia mistakenly used nitrogen as a substitute for the plant’s internal air. Moreover, no certification or oxygen level analysis was carried out before entering the tank, and Liu fainted from asphyxiation after entering it. Wang, eager to save lives, entered the tank blindly without taking any precautions and also suffered from asphyxiation. Fortunately, prompt rescue efforts prevented any casualties. 0 V. l0 S5 X) I# i& l) j Please analyze the direct and indirect causes of the accident. * ? (X$ n6 n1 t L; I9 K What violations do the operators commit? : y$ Q. j Z4 f# m* `* J4 W7 FHow can similar accidents be prevented from happening again? Reasons and violations: 1. Misoperation occurred during personnel replacement; indirectly, there were no pipeline markings on the nitrogen pipelines and compressed air pipelines ； 3. Staff violated operating procedures by failing to obtain permits for working in confined spaces and by not conducting oxygen level tests; indirectly, this reflects inadequate management ； 4. The personnel entered the tank without taking effective protective measures, and no detailed emergency procedures were established in advance. To prevent similar accidents from occurring: 1. Improve the labeling of pipelines in the work area ； 2. Develop detailed procedures for working in confined spaces, and enforce these procedures strictly ； 3. Strengthen daily education for employees to improve their psychological qualities ； 4. Before carrying out work in confined spaces, conduct a risk assessment to identify potential accidents, establish appropriate emergency response measures, and prepare emergency rescue equipment.

I. Direct cause: The tanker was filled with nitrogen, resulting in oxygen deficiency； Indirect cause: No oxygen content analysis was performed before entering the container. II. Violations: This accident was primarily related to the issue of working inside containers. There are eight essential requirements for entering a container: 1. An application must be submitted and approved ； 　　2. Safety isolation must be carried out ； 　　3. Replacement and ventilation must be carried out ； 　　4. Safety analysis must be conducted within the specified time frame ； 　　5. Required protective equipment must be worn ； 　　6. There must be someone monitoring outside the device ； 　　7. Supervisors must remain at their posts ； 　　8. Rescue equipment and measures must be available. The main violation is entering the container without obtaining a work permit, as well as without having a special permit for working in confined spaces ； No safety analysis was conducted ； The wrong replacement gas was used; there may have been no labeling, nor any analysis conducted ； It’s possible that the appropriate personal protective equipment wasn’t worn ； Entering a container to rescue someone without protection is also considered a violation of regulations ； III. 1. Strictly implement the ticket system for entering containers ； 2. Strictly implement material labeling ； 3. Hold an accident analysis meeting to strengthen safety education for employees.

I. Analyze the direct and indirect causes of the accident. Answer: 1. Direct cause: 1) Operational error. Workers Wang, Liu, Zhao, and Jia made mistakes in their operations by using nitrogen instead of compressed air to purge the tank truck, resulting in the presence of asphyxiating gases inside the tank; 2) Entering a dangerous area recklessly. Wang, eager to save lives, entered the tank without taking any protective measures ； 2. Indirect causes: 1) The chemical plant had deficiencies in safety management, with inadequate oversight. Relevant safety procedures were not followed before entering the tank, no safety plan was established, and oxygen analysis of the gas inside the tank was not properly carried out ； 2) Inadequate safety education results in operators having a weak sense of safety and poor self-protection skills, which leads to accidents. In particular, attempting to rescue others recklessly without taking any personal safety precautions almost exacerbated the situation ； II. What are the violations committed by the workers? Answer: 1. Operational errors, neglect of safety ； 2. Violation of operating procedures ； 3. rashly entering dangerous places ； 4. Failure to wear protective gear. III. How to prevent similar accidents from occurring? Answer: 1. Strengthen safety and technical training for employees to improve their safety awareness and self-protection capabilities. Achieve a 100% identification rate of hazards at the work posts. 2. During construction, maintenance, and temporary fault repairs, it is necessary to develop a construction and maintenance plan, obtain a fire work permit, provide the necessary safety and technical instructions, and ensure that all safety measures are properly implemented. 3. Strengthen the organization for work safety and implement relevant responsibilities. When carrying out maintenance or temporarily addressing faults, supervisory leaders or grassroots managers must be present on site to exercise overall command and oversee the implementation of all safety measures to ensure safety.

Reply to 1# shmily327: 1. Direct cause – four operators made mistakes by entering the tank without having oxygen level data. 2. Indirect cause – negligence on the part of the workshop supervisors； Failing to obtain the necessary permits before entering the tank and conducting oxygen level analysis can lead to problems; therefore, permits must be obtained and oxygen levels analyzed before entering the tank. When multiple people are involved in the operation, personnel with strong responsibility and high technical skills should be assigned to oversee it

Immediate cause: Carelessness on the part of the operator, who failed to follow the operating procedures； Indirect cause: Lack of knowledge regarding pipe colors, or absence of conspicuous markings ； Violation: Liu failed to obtain the necessary permits and conduct an oxygen level analysis before entering the tank, while Wang, in his eagerness to save someone, failed to take any preventive measures ； To prevent safety accidents, it is necessary to raise safety awareness and strictly follow operating procedures. In the event of an accident, appropriate measures must be taken; one can save others only by protecting themselves first, thereby achieving the principle of \"no harm to oneself, no harm to others, and no harm caused by others.\"