Accident Case Analysis: One question per Monday, Answer analysis (1-5)

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This post was last edited by wang*nhua77020 on 2016-6-11 00:15. Thank you all for participating in the analysis of these accident cases; those who contributed well will receive an additional +1 charm point. The list of winners is attached at the end of each case’s answer. Please reply to this post in the specified format to claim your prize. The format for replies is as follows: Winner’s case: X. Case 1: On June 6, 2014, an explosion occurred in Tank No. 2 containing gasoline in the tank farm of Refinery No. 8, resulting in 1 death, 3 minor injuries, and direct economic losses of 4.2 million yuan. The oil tank is a dome-type tank with a capacity of 200 m3. The oil inlet pipe of the tank enters the tank from the top but does not reach the bottom of the tank. There was an original level gauge in the tank, which was removed due to malfunction. 　　On May 20, 2014, the oil tank underwent cleaning and maintenance. At 8:00 on June 6, oil transfer to the tank began. When the gasoline was fed in from the top of the tank, the flow rate inside the inlet pipe was 2.3–2.5 m/s, which caused the gasoline to splash violently inside the tank, leading to an explosion. The explosion flung the entire tank lid off the oil tank. While trying to put out the fire, the personnel on site found that the foam generator was not producing foam; in their haste, they used water guns to extinguish the fire, which caused the fire to spread. 　　Upon arrival, the fire brigade extinguished the fire using foam. 　　After the accident, investigations and analyses revealed that the foam fire suppression system was functioning properly; the reason why no foam was produced by the foam generators was improper operation by the personnel on site, who opened the wrong valves. In response to the issues revealed by this incident, the plant has strengthened safety training for its employees, installed an automatic monitoring system on-site, improved the labeling and signage of on-site equipment and facilities, and formulated an emergency response plan for safe production. 　　Based on the above scenario, please answer the questions.
1. According to the “Regulations on the Reporting, Investigation and Handling of Work Safety Accidents”, this accident falls under category ( A ).
A. General accident
B. Relatively serious accident
C. Serious accident
D. Extremely serious accident
E. Particularly serious accident

Article 3: Based on the number of casualties or direct economic losses caused by work safety accidents (hereinafter referred to as “accidents”), accidents are generally classified into the following categories:
(1) Particularly serious accidents refer to those resulting in 30 or more deaths, or 100 or more severe injuries (including acute industrial poisoning, the same hereinafter), or direct economic losses exceeding 100 million yuan.
(2) Serious accidents refer to those resulting in between 10 and 30 deaths, or between 50 and 100 severe injuries, or direct economic losses ranging from 50 million yuan to 100 million yuan.
(3) Relatively serious accidents refer to those resulting in between 3 and 10 deaths, or between 10 and 50 severe injuries, or direct economic losses ranging from 10 million yuan to 50 million yuan.
(4) General accidents refer to those resulting in fewer than 3 deaths, or fewer than 10 severe injuries, or direct economic losses under 10 million yuan. 　　2 In accordance with the Regulations on the Reporting, Investigation, and Handling of Production Safety Accidents, the person in charge of the refinery shall, upon receiving reports of this accident, submit the accident information via telephone within (A ) to the local county-level people’s **work safety supervision department. 　　A.1h 　　B.2h 　　C.24h 　　D.7d 　　E.30d Article 9: After an accident occurs, the persons present at the accident site shall immediately report to the person in charge of their unit; upon receiving such a report, the person in charge shall, within 1 hour, report to the work safety supervision and management department at or above the county level in the location where the accident took place, as well as to the relevant departments responsible for work safety supervision and management. 　　3. The safety technical measures to prevent such fire and explosion incidents include (　ABD)　A. Controlling the flow rate of oil input to prevent splashing B. Ensuring reliable grounding of the tank C. Strengthening management and training D. Reinstalling the level gauge E. Increasing the size of the fire pond C is not a technical measure ； It is a management measure ； E: It is a type of technical measure, but it is not applicable to this case: (Foam systems were used for fire suppression in this case, rather than water.) 4. The members of the accident investigation team should include personnel from (ABE). 　　A. Work safety supervision and management department B. Supervisory authority C. Labor and social security department D. News media E. Public security organs Article 22: The composition of an accident investigation team shall follow the principles of simplicity and efficiency. 　　Depending on the specific circumstances of the accident, the accident investigation team is composed of representatives from the relevant people’s authorities, work safety supervision and management departments, departments responsible for work safety supervision and management, supervision agencies, public security organs, and trade unions; the People’s Procuratorate shall also be invited to send representatives to participate. 　　5. In the aforementioned cases, the emergency rescue measures that should be taken immediately after a fire or explosion occurs include (ABC). A. Call the police B. Evacuate people C. Extinguish the fire. D. Hold those responsible for the accident accountable. E. Provide compensation to those who were injured or killed. An emergency response procedure should be initiated right away after the accident (which includes ABC), while DE represent actions that are carried out after the accident ； 　　6. After an accident occurs, among the following expenses incurred by the enterprise, those that constitute safety investments are (BCDE). A. Expenses for dealing with the aftermath of the accident; B. Expenses for safety technology training; C. Expenses for installing automatic monitoring systems; D. Expenses for improving signs and markings on equipment and facilities on site; E. Expenses for developing emergency response plans for safe production. Safety investments refer to all the expenses incurred to enhance the systematic safety of an enterprise, prevent various accidents, avoid work-related injuries and deaths, eliminate potential accident hazards, and control dust and toxic substances – in other words, they are all the expenses spent to protect the safety and health of employees during the production process. It includes five components: costs for safety technical measures, costs for industrial hygiene measures, expenses for safety training, costs for personal protective equipment, and costs for daily safety management. (Therefore, choose B, C, D, E.) Those who answered all questions correctly in this case: @zjzc168. Case 2: At 18:00 on August 6th of year X, driver A drove a tank truck loaded with liquid chlorine onto section B56 of a highway. Around 20:00, the tank truck collided with a truck driven by driver B, resulting in damage to the tank truck, its rupture, and the leakage of liquid chlorine; this led to the death of all passengers in both vehicles, except for driver A. After the collision, driver A, despite the severe damage to the tank truck and the fact that liquid chlorine was already leaking, did not call the police nor take any action; instead, he fled the scene quickly. As a result of the delay in taking emergency action, the leaked liquid chlorine rapidly vaporized and spread, causing widespread contamination. This led to 30 villagers living near section B56 of the highway dying from poisoning, 285 people being hospitalized, and nearly 10,000 people having to be evacuated urgently. At 2 a.m. on the 7th, emergency responders arrived at the scene, organized the urgent evacuation of the villagers and the search for those injured in the area affected by the chlorine pollution, and carried out emergency measures at the site. According to the Interim Provisions on the Procedures for Investigating Extraordinarily Serious Accidents, the tasks of the team tasked with investigating such accidents include (D). A. Inviting military personnel to participate in the investigation of the accident. B. Participating in the management of vehicles carrying chemicals on the highways along the route. C. Handling emergency responses and alerts related to sudden incidents. D. Interrogating motor vehicle driver A. E. Establishing accident rescue mechanisms and continuously improving the systems for accident rescue. Article 20: The responsibilities of the team investigating extraordinarily serious accidents are as follows: (1) Determining the causes of the accident, as well as the number of casualties and property losses incurred ； (II) Determine the nature of the accident and liability ； (III) Propose recommendations on measures to be taken for handling the incident and preventing similar incidents from occurring in the future ； (IV) Put forward suggestions regarding the handling of those responsible for the accident ； (5) Check whether the emergency measures for controlling accidents are appropriate and have been implemented ； (VI) Prepare an accident investigation report. E: Just propose corrective measures ； It does not involve establishing a rescue mechanism ； 　　2. In accordance with the Provisions on the Reporting, Investigation and Handling of Production Safety Accidents (Decree No. 493 of the State Council), this accident falls under category (A) of accidents. 　　A. Extraordinarily serious B. Serious deaths C. Severe injuries D. Ordinary deaths E. Injuries or deaths among workers Article 3: Based on the number of casualties or direct economic losses caused by production safety accidents (hereinafter referred to as accidents), accidents are generally classified into the following categories: (1) An extraordinarily serious accident refers to an accident that results in 30 or more deaths, or 100 or more severe injuries (including acute industrial poisoning, the same below), or direct economic losses of over 100 million yuan; (2) A serious accident refers to an accident that results in 10 to 30 deaths, or 50 to 100 severe injuries, or direct economic losses of between 50 million yuan and 100 million yuan; (3) A relatively serious accident refers to an accident that results in 3 to 10 deaths, or 10 to 50 severe injuries, or direct economic losses of between 10 million yuan and 50 million yuan; (4) An ordinary accident refers to an accident that results in 3 or fewer deaths, or 10 or fewer severe injuries, or direct economic losses of less than 10 million yuan. 　 　3. Collecting evidence in accident investigations is a very important part of such investigations. This process includes (　ABD)　A. Gathering factual information related to the accident; B. Carrying out emergency rescue operations; C. Offering comfort to those involved in the rescue efforts; D. Searching for driver A; E. Reporting the progress of the investigation through the media. B and E fall under emergency response measures, not evidence collection.　4. According to the “Classification of Work-related Injuries and Deaths in Enterprises” (GB 6441–1986), the items that can be considered direct economic losses resulting from this accident include (　ABCD)　A. Funeral expenses and lost wages for those who died as a result of poisoning; B. Compensation and assistance funds for those who were injured and required hospital treatment; C. Medical expenses incurred by those who were injured and hospitalized; D. Accident compensation, fines, and other related costs; E. Valid economic expenditures incurred during the period when the tank truck was out of service. These are all considered direct economic losses: ① Expenses related to injuries and deaths. This includes medical expenses (including nursing care), funeral and bereavement expenses, subsidy and relief expenses, and lost wages, etc. ②Costs for post-incident handling. This includes administrative costs related to handling the accident, on-site rescue costs, site cleanup costs, accident fines, and compensation expenses. Production loss costs. This includes losses of fixed assets and losses of current assets. E. Indirect economic losses 5. According to the **Regulations on the Safe Management of Chemicals**, transportation companies must possess (ABC). A. Qualifications for carrying out transportation activities B. Systems for training drivers and providing them with safety education C. Necessary emergency response equipment and protective gear D. Basic cleaning and personal hygiene supplies E. A license for transporting chemicals. Answer: A, B, C Article 43: Those engaged in the road or water transport of hazardous chemicals must obtain permits for road transport of hazardous goods and permits for water transport of hazardous goods in accordance with the relevant laws and administrative regulations governing road and water transport, and they must also register with the industrial and commercial authorities. Dangerous *an Chemical road and waterway transport enterprises shall appoint full-time safety management personnel. Article 44: Drivers, crew members, loading and unloading supervisors, escorts, declarants, and on-site container stuffing inspectors employed by road and waterway transport enterprises handling hazardous chemicals must pass assessments conducted by the transportation authorities and obtain the necessary qualifications for their respective roles. The specific measures shall be formulated by the transportation department of the State Council. Article 45: When transporting hazardous chemicals, corresponding safety precautions shall be taken in accordance with the hazardous characteristics of such chemicals, and necessary protective equipment as well as emergency rescue supplies shall be provided. E should be a permit for the road transport of hazardous goods ； It is not a chemical transportation permit. All correct individuals: @cicwht @329135447 @Ma Xueye. Case 3: Company A Copper is a holding subsidiary of a large enterprise. In 2013, Company A for Copper built a new facility to produce copper and sulfuric acid using the Isa smelting technology. The project commenced construction in January 2013 and was put into operation on September 10. The main process equipment for the project includes Aisa melting furnaces, electric furnaces, waste heat boilers, etc. The high-temperature flue gas generated by the Isa smelting furnace enters the waste heat boiler, where steam is produced through heat exchange; the flue gas after heat exchange is then treated by a dust removal and purification system before being discharged. The waste heat boiler is designed with a rated steam pressure of 2.5 MPa, a rated evaporation capacity of 35 t/h, and a rated steam temperature of 350°C. 　　At 20:00 on November 24, 2013, the on-duty dispatcher A heard a loud noise, and immediately saw on the monitoring system screen that a large amount of steam was escaping from the waste heat boiler. A immediately activated the alarm in accordance with the emergency response plan, ordered an urgent shutdown of the furnace and the evacuation of personnel on site, and reported to Company General Manager B. Upon receiving the report, Yi immediately informed the relevant higher-level departments and rushed to the scene to oversee the rescue efforts. At 21:00, after a headcount, it was found that 5 workers remained unaccounted for. Party B dispatched 2 workers to the scene to assess the situation; however, due to the excessive steam at the site, both workers suffered burns. Thus, protective gear was urgently dispatched; the rescue workers put on the protective gear and entered the residual heat boiler room, where they found 4 workers dead and 1 seriously injured. It was later determined that at the time of the accident, the operating pressure of the waste heat boiler was 2.3 MPa and the steam temperature was 310°C. The corrugated metal hose in the cooling screen, which connected the melting furnace to the waste heat boiler, burst, causing a large amount of high-temperature saturated steam to be released, which led to casualties among the people on site. The direct economic loss from this accident was 4.2 million yuan. 1. According to the \"Classification of Accidents Involving Employees in Enterprises,\" the category of this accident is (　B)　A. Object strike　B. Burns　C. Boiler explosion　D. Container explosion　E. Fire. This accident was caused by the rupture of a metal hose, resulting in burns from high-temperature steam; burns refer to injuries caused by strong acids or bases splashing on the body, burns caused by flames, burns caused by hot objects, or skin damage caused by radiation ； Excludes burns caused by electrical injuries and fire accidents ； Explosion of a pressurized vessel: This refers to a gas explosion caused by the rupture of the pressure vessel (a physical explosion), as well as a chemical explosion that occurs when the flammable liquefied gases contained within the vessel evaporate immediately after the vessel ruptures, mix with the surrounding air to form an explosive gas mixture, and then come into contact with a source of fire. 　　2. The direct cause of this accident may be (　C 　) 　A. Excessively high temperature of the flue gas in the melting furnace 　B. Excessively high pressure of the hot flue gas in the melting furnace 　C. Substandard quality of the corrugated metal hose 　D. Workers on site not wearing personal protective equipment 　E. Unreasonable design of the boiler room, as the operating parameters were within the specified limits ； And the pipeline burst ； The possible reason is substandard quality of the hose ； (Direct cause) ； 　　3. According to the List of Occupational Diseases, the occupational diseases that this furnace operator may contract include (ACD). A. Pneumoconiosis B. Occupational radiological diseases C. Occupational poisoning D. Occupational diseases caused by physical factors E. Occupational diseases caused by biological factors. If the company has installed a dust removal system, it indicates that there is dust present at the workplace ； It may lead to pneumoconiosis ； The combustion process may produce CO; the presence of SO2 can lead to occupational poisoning. High temperatures can cause heatstroke: (occupational diseases caused by physical factors). 4. According to the regulations, the units that should be part of the accident investigation team include (ABC): A. The quality and technical supervision department at the municipal level (in cities with districts); B. The work safety supervision and management department at the municipal level (in cities with districts); C. The people’s procuratorate at the municipal level (in cities with districts); D. The human resources and social security department at the municipal level (in cities with districts); E. The parent company of A Copper Company. Article 22 of the Regulations on the Reporting, Investigation, and Handling of Production Safety Accidents states that the composition of the accident investigation team should follow the principles of simplicity and efficiency. Depending on the specific circumstances of the accident, the accident investigation team is composed of representatives from the relevant people’s authorities, work safety supervision and management departments, departments responsible for work safety supervision and management, supervision agencies, public security organs, and trade unions; the People’s Procuratorate shall also be invited to send representatives to participate. Pressure vessels are supervised by the quality and technical supervision authorities; therefore, these authorities were involved in this accident as well ； 　　5. Based on the emergency response process for that incident, the elements that need to be added or improved in A Copper Company’s accident emergency plan include (　CD)　　A. Dispatcher emergency response procedures　　B. Incident reporting procedures　　C. Requirements for emergency equipment　　D. Emergency handling procedures　　E. Personnel counting procedures. According to the description of the incident, there are no issues with A, B, and E ； The main problems include: insufficient preparation of emergency supplies ； When the employees went missing, designated personnel went to the site to look for them, and as a result two workers suffered burns: this indicates that the company’s emergency response plan lacks adequate measures for dealing with such situations ； Those who got all answers correct: @Lszhoujidai @chuanhengmpq @cicwht @zjzcl168 @AICHUAN Soy Sauce @LLawliet @Itldln123. Case 4: A construction company, where the business manager serves as the legal representative, and there is also a person in charge of on-site work safety management. During the construction of a project at its location of registration, while directing the assembly of the tower crane, the team leader of Team A failed to properly install the anti-slip plates on the crane’s boom into the dovetail grooves and secure them with bolts, instead welding the anti-slip plates in place. One day, during operations in Shift A, an accident occurred due to the welding failure of the boom anti-slip plate and the breakage of the boom, resulting in 3 deaths and 1 serious injury. The losses resulting from this accident include: medical expenses (including nursing costs) of 450,000 yuan, expenses for funerals and compensation amounts to 600,000 yuan, costs related to handling the accident and carrying out rescue efforts at the scene amounting to 280,000 yuan, equipment losses of 2 million yuan, and losses due to suspension of operations amounting to 1.5 million yuan. 1. The main person responsible for this accident is (D). A. Enterprise manager B. Person in charge of on-site safety management C. Workers from Team A involved in this accident D. Team leader of Team A E. Members of Team A. Direct causes: ① Unsafe conditions of machinery, materials, or the environment: D. Welding failure in the anti-slip plates of the tower crane’s boom. ② Unsafe human behavior: A. Unauthorized modifications and use of unstable facilities. Therefore, the main person responsible for the accident is the team leader of Team A.

2. Based on the above description, the direct economic loss resulting from this accident is (D) ten thousand yuan. A. 45 B. 105 C. 133 D. 333 E. 483. Direct economic losses include: medical expenses (including nursing costs) of 450,000 yuan, funeral and compensation costs of 600,000 yuan, costs related to accident handling and rescue efforts of 280,000 yuan, and equipment losses of 2,000,000 yuan. In total, this amounts to 3,330,000 yuan.

3. According to the “Regulations on Work Safety in Construction Projects,” the following statements are correct (B, C, E). A. The department responsible for work safety supervision and management at the county-level or higher level in the administrative region where the enterprise is located is responsible for overseeing the work safety aspects of the enterprise’s construction projects. B. This construction project must have a construction permit. C. Fines can be imposed as a penalty for violations related to work safety in construction projects. D. Construction companies must provide accident insurance for all their employees. E. The team leader of Team A must hold a qualification certificate for special operations. Article 39 states that the department responsible for work safety supervision and management under the State Council shall, in accordance with the “Work Safety Law of the People’s Republic of China,” exercise comprehensive supervision over work safety in construction projects across the country. Therefore, statement A is incorrect: The departments responsible for work safety supervision and management at the local people’s government level at or above the county level shall, in accordance with the provisions of the Work Safety Law of the People’s Republic of China, exercise comprehensive supervision and management over work safety in construction projects within their respective administrative regions. Article 38: The construction unit shall arrange for accident insurance for personnel carrying out hazardous operations at the construction site. The accident insurance premium is paid by the construction party. In the case of a general construction contract, the general contractor shall pay the accident insurance premiums. The term of the accidental injury insurance covers the period from the start of construction work until the project is completed and approved. Therefore, option D is incorrect. Article 10: When applying for a construction permit, the construction entity shall provide documentation regarding safety measures for the construction project. Article 25: Special-type workers such as operators of vertical transportation machinery, installation and dismantling workers, blasting workers, crane signalers, and workers engaged in high-altitude erection tasks must receive specialized safety training in accordance with relevant regulations and obtain a special-type work operation qualification certificate before they can start working. 　　4 After such an accident occurs, the departments and units that should make up the accident investigation team include (　A C)　　A. Local municipal work safety supervision and management departments　　B. Engineering supervision agencies　　C. Local municipal public security departments　　D. County-level environmental protection departments　　E. County-level trade unions　　Article 22: The composition of the accident investigation team shall follow the principles of simplicity and efficiency. Depending on the specific circumstances of the accident, the accident investigation team is composed of representatives from the relevant people’s authorities, work safety supervision and management departments, departments responsible for work safety supervision and management, supervision agencies, public security organs, and trade unions; the People’s Procuratorate shall also be invited to send representatives to participate. E is incorrect ； It should be a trade union at the prefecture-level, not at the county level. 5 According to the “Rules for Investigating and Analyzing Accidents Involving Injuries or Deaths of Enterprise Employees” (GB6442–1986), the direct causes of this accident include (A, D). A. Unauthorized modifications were made, and unstable equipment was used. B. The operator of the tower crane failed to pay proper attention during operation. C. Safety management at the construction site was inadequate. D. The anti-slip plates on the tower crane’s boom had weld cracks. E. The safety responsibility system was not properly established. Direct causes are those related to unsafe conditions of machinery, materials, or the environment: D. Weld cracks in the anti-slip plates on the tower crane’s boom. Unsafe human behavior: A. Unauthorized modifications and use of unstable equipment. All other options are indirect causes. 6 According to the “Regulations on the Safety Supervision of Special Equipment” and the circumstances of this enterprise, the correct statements are (B, C, D). A. The design documents for the tower crane must be evaluated by experts organized by the safety supervision department before it can be manufactured. B. After installation, the tower crane must undergo inspection by a qualified testing agency before it can be put into use. C. The enterprise must establish emergency response measures and plans for dealing with accidents involving tower cranes. D. After this accident occurred, the enterprise must promptly report it to the safety supervision department for special equipment and other relevant authorities. E. When applying for approvals related to special equipment, the safety supervision department must complete the processing within 40 days. According to Article 35 of the “Regulations on Safety Management in Construction Projects”, before using construction hoists, self-erecting scaffolding, formwork, and other similar facilities, the construction unit must organize relevant parties to conduct inspections, or it may Commission a qualified testing agency to carry out these inspections ； When leased mechanical equipment, construction tools, and accessories are used, the acceptance is carried out jointly by the general construction contractor, subcontractors, the leasing party, and the installation unit. It can only be used after passing the acceptance inspection. Construction lifting machinery as specified in the Regulations on Safety Supervision of Special Equipment shall undergo supervised inspection by a qualified inspection and testing institution and pass such inspection prior to acceptance. The construction contractor shall, within 30 days as of the date when the construction lifting machinery, as well as self-erecting scaffolding, formwork and other similar installation facilities pass the inspection, register with the construction administrative department or other relevant authorities. The registration mark shall be placed or attached in a prominent position on the device. Therefore, B is correct and E is incorrect ； Article 50: In the event of a work safety accident at a construction unit, it shall, in accordance with **the relevant regulations on the reporting, investigation, and handling of casualty accidents, promptly and truthfully report to the department responsible for work safety supervision and management, the administrative department in charge of construction, or other relevant departments ； In the event of an accident involving special equipment, it is also necessary to report to the department responsible for the safety supervision and management of special equipment. The department that receives the report shall submit a truthful report in accordance with **relevant regulations**. Therefore, D is correct ； Article 49: Construction units shall, in light of the characteristics and scope of construction projects, monitor those parts and stages of the construction site where major accidents are likely to occur, and formulate emergency rescue plans for production safety accidents at the construction site. In the case of a general construction contract, the general contractor is responsible for organizing the preparation of an emergency rescue plan for production safety accidents in construction projects. The general contractor and the subcontractors shall, in accordance with this emergency rescue plan, establish their own emergency rescue organizations or assign emergency rescue personnel, provide rescue equipment and apparatus, and conduct regular drills. Therefore, C is correct ； A is likely incorrect: Only enterprises with the qualifications to produce special equipment are allowed to manufacture such equipment ； Species equipment must be inspected before it can leave the factory ； 　　7. Regarding this accident, the correct statements are (D, E). A. According to the principles for classifying accidents in industrial and commercial enterprises, this accident is considered a minor death accident. B. According to those same principles, this accident is classified as a major accident. C. When interviewing the injured individuals who have not yet recovered, the conversation should not last more than 2 hours. D. The investigation report for this accident should include basic information about the enterprise. E. This accident was caused by negligence. Article 3 of the Regulations on the Reporting, Investigation, and Handling of Production Safety Accidents states that, based on the number of casualties or direct economic losses resulting from a production safety accident, such accidents are generally classified into the following categories: (1) Extraordinarily serious accidents refer to those that result in 30 or more deaths, or 100 or more serious injuries (including acute industrial poisoning), or direct economic losses of over 100 million yuan ； (II) A major accident refers to an accident that results in 10 to 30 deaths, or 50 to 100 serious injuries, or direct economic losses ranging from 50 million yuan to 100 million yuan ； (III) A major accident refers to an accident that results in 3 to 10 deaths, or 10 to 50 serious injuries, or direct economic losses ranging from 10 million yuan to 50 million yuan ； (IV) A general accident refers to an accident that results in 3 or fewer deaths, 10 or fewer serious injuries, or direct economic losses of less than 10 million yuan. . Therefore, A B is incorrect (B should refer to a more serious accident). Article 12: An accident report shall include the following information: (1) An overview of the unit where the accident occurred ； (II) The time and place of the accident, as well as the conditions at the accident scene ； (III) Brief account of the accident ； (IV) The number of casualties caused or likely to be caused by the accident (including those unaccounted for) and the preliminary estimate of direct economic losses ； (5) Measures already taken ； (VI) Other circumstances that should be reported. Therefore, D is correct. There should be no specific rules for C; it mainly depends on their physical condition ； Those who answered correctly: @wangld @zhaozq2015 @zhangqi1234 @LLawliet. In Case 5 involving a furniture manufacturing enterprise, there are processes such as sanding, polishing, and grinding of painted wooden components within the woodworking workshop. The workshop also contains organic solvents and discarded paint cans. The dust removal and purification system in the workshop uses a reverse-blow bag filter. The addition of new equipment and the expansion of production capacity have resulted in dust concentrations exceeding the allowed levels in the workshop. To control dust pollution in the workshop, the number of bag filters was increased from 4 to 8, and the concentration of wood dust in the workshop is now less than 10 mg/m3 after treatment. 　　At 9:20 on July 5, 2014, an explosion and fire occurred in dust collector No. 3 of the dust removal and purification system, which immediately triggered an explosion and fire in dust collector No. 4 as well, resulting in damage to some buildings and facilities within a 20-m radius of the site of the explosion. Since there was no one in the area where the explosion occurred, no injuries were reported. 1 According to the \"Classification of Fires\" (GB 4968–2008), fires are classified based on the burning characteristics of substances. This accident falls under category (A). A. Class A fire B. Class B fire C. Class C fire D. Class D fire E. Class E fire. The \"Classification of Fires\" (GB/T 4968–2008) was issued on November 4, 2008, and came into effect on May 1, 2009. Fires are divided into seven categories: A, B, C, D, E, F, and K, depending on the type of combustible material and its burning characteristics. 　　Class A fire: refers to fires involving solid materials. This substance usually has the properties of organic matter and generally produces hot embers when burned. Such as fires involving wood, coal, cotton, wool, linen, paper, etc. 　　Class B fires: refer to fires involving liquids or fusible solid materials. Fires involving kerosene, diesel, crude oil, methanol, ethanol, asphalt, paraffin, etc. 　　Class C fire: refers to gas fires. Such as fires involving gas, natural gas, methane, ethane, propane, hydrogen, etc. 　　Class D fire: refers to fires involving metals. Such as fires involving potassium, sodium, magnesium, aluminum-magnesium alloys, etc. 　　Class E fire: Fire involving electrical current. A fire in which an object burns due to being charged. 　　Class F fire: Fires involving cooking materials in cooking appliances (such as animal and vegetable fats). Class K fire: Fires involving cooking oils. Generally, the average combustion rate of cooking oil is higher than that of hydrocarbon-based oils. Compared to other types of liquid fires, cooking oil fires are difficult to extinguish; due to its many behaviors that differ from those of hydrocarbon oil fires, it is classified as a separate category of fire. 　To prevent such accidents from occurring again, the safety technical measures that the company can adopt include (A, B, E). A. Using anti-static filtering materials in the bag dust collection system; B. Implementing an explosion-proof design for the dust collection rooms; C. Conducting regular fire and explosion prevention drills; D. Establishing an approval process for operations involving open flames; E. Increasing the frequency of cleaning the dust collector bags. Safety technical measures aimed at preventing accidents are those that involve imposing restrictions on energy or hazardous substances in order to prevent their accidental release. Common safety measures used to prevent accidents include: ① Eliminating hazard sources. ②Restrict energy or hazardous substances. ③Isolation. ④Faults – Safety design. ⑤Reduce failures and mistakes. Reducing accidents? Technical measures aimed at preventing accidental release of energy from causing harm to people or damage to objects, or at minimizing such harm and damage, are known as safety measures for reducing accident losses. Such technical measures are employed after an accident occurs to quickly bring the situation under control, prevent the accident from spreading, avoid secondary accidents, and thereby reduce the losses caused by the accident. Common safety technical measures used to reduce accident losses include: ① Isolation. ②Identify weak points. ③Personal protective equipment. ④Shelter and rescue. Electrical safety ① Neutral and grounding protection systems. ②Leakage protection. ③Insulation. ④Electrical isolation. ⑤Safe voltage. ⑥Shielding and safety distance. ⑦Chain protection. Mechanical safety ①: Use intrinsically safe technologies. ②Limit mechanical stress. ③Safety of materials and substances. ④Adhere to safety ergonomics principles. ⑤Safety principles for designing control systems. ⑥Safety protection measures. 　 Therefore, A is used to eliminate the hazard source ； B stands for isolation. E. is to reduce failures and mistakes ； 　　3 According to the \"Hygienic Standards for the Design of Industrial Enterprises\" (GBZ 1—2010), among the following statements regarding the design and installation requirements for a dust removal system in such enterprises, the correct ones are (C, D, E). A. Pipes for transporting dusty gases must be installed horizontally. B. When horizontal pipes are used, it is not necessary to provide cleaning holes. C. Pipes for transporting dusty gases should be at an appropriate angle to the ground. D. In dust removal systems dealing with explosive dusts and toxic or harmful gases, detection devices should be installed. E. To facilitate testing, testing holes should be provided at appropriate locations within the dust removal system. 6.1.5.1 The design of ventilation, dust removal, and gas emission control systems shall comply with the requirements of relevant technical specifications and regulations for dust and gas prevention. i) Ducts for conveying dusty gases should be installed vertically or at an angle; when installed at an angle, the angle with the horizontal plane should be >45°. If horizontal pipes must be installed, they should not be too long, and cleaning holes should be provided at appropriate locations to facilitate the removal of dust buildup and prevent pipe blockages. Therefore, A and B are incorrect; C is correct ； j) Depending on the dust category, a minimum economic flow velocity must be ensured within the ventilation ducts. To facilitate the testing of the dust removal system, test ports that can be opened and closed should be provided at the inlet and outlet of the dust collector during design. These test ports should be located in sections of the duct where the airflow is stable, and they should be able to be closed when not in use for testing. In purification systems for explosive dusts and toxic and harmful gases, continuous automatic detection devices should be installed. Therefore, D is correct ； 6.1.6.2 Work locations where toxic gas detectors and alarms should be installed are preferably equipped with fixed-type devices; when it is not possible to use fixed-type devices, portable detectors and alarms should be provided. Therefore, E is correct ； 　　4 According to the \"Classification and Codes of Hazards and Dangerous Factors in the Production Process\" (GB/T13861–2009), the physical hazards and dangerous factors present in this enterprise include (A, B, C, D). A. Wood dust B. Noise generated during the sanding, polishing, and grinding of painted wooden items C. Poor working conditions D. High-temperature substances E. Volatile organic gases such as those from organic solvents used and paint remaining in discarded paint cans. D is not a physical hazard factor ； 　　5 The direct causes of this accident may include (A, C, D). A. The dust concentration inside the dust collector reached the explosive limit. B. The temperature in the workshop was too high. C. The flow rate of the dusty gas inside the dust collection pipes was too fast. D. The dusty gas contained metal particles. E. The humidity of the dusty gas inside the dust collector was too high. Direct causes are those related to human unsafe behaviors; no such behaviors were involved in this case ； Therefore, the cause should not be sought in people’s unsafe behaviors ； 　Unsafe conditions of machinery, materials, or the environment: The main cause of this accident was the combustion explosion of dust; the following conditions had to be met: the dust reached its explosive limit. Therefore, option A is correct ； At the same time, there must be a source of ignition: there could be two such sources – static electricity sparks generated by too high flow rates of flammable gases in the pipelines ； Or metal particles in the dust collide with the pipelines, generating sparks ； Therefore, there are two possible sources of ignition: Those who answered all CD questions correctly: @wangld @xsaqwe @jzcl16