Everyone, take a look at this question

Which of the following fire extinguishers is suitable for extinguishing fires involving oils, flammable gases (ABD)? A、Dry powder B、CO2 C、H2O D、1211

Since there are oils present, C definitely cannot be chosen.

In accordance with GB 50140-2005 \"Code for Design of Fire Extinguisher Installation in Buildings\", fires involving oils, combustible, and flammable gases are classified as Class B and Class C fires. 4.2 Selection of Fire Extinguisher Types 4.2.2 For areas where Class B fires occur, foam fire extinguishers, sodium bicarbonate dry powder fire extinguishers, ammonium phosphate dry powder fire extinguishers, carbon dioxide fire extinguishers, water-based fire extinguishers designed for Class B fires, or halon fire extinguishers should be used. In areas where Class B fires occur involving polar solvents, water-resistant fire extinguishers designed to extinguish Class B fires should be used. 4.2.3 For Class C fire sites, ammonium phosphate dry powder fire extinguishers, sodium bicarbonate dry powder fire extinguishers, carbon dioxide fire extinguishers, or halon fire extinguishers should be selected.

Not necessarily; GB 50140-2005, the Code for Design of Fire Extinguisher Installation in Buildings, introduces water-based fire extinguishers designed for extinguishing Class B fires, thereby changing the previous situation in China where such extinguishers could only be used to put out Class A fires and not Class B fires.

So it means choosing all four; this question is really confusing

The Code GB 50140-2005 for Design of Fire Extinguisher Installation classifies fires as follows: 3.1.2 The types of fires in areas where fire extinguishers are installed can be divided into the following five categories: 1 Class A fires: Fires involving solid materials. Class 2 B fires: Fires involving liquids or fusible solid materials. 3 Class C fire: Gas fire. 4 Class D fire: Metal fires. Class 5 E fire (electrical fire): A fire in which an object is burning due to an electric charge. At the same time, this standard specifies the following for the selection of different types of fire extinguishers for various fire scenarios: 4.2.1 For Class A fire areas, water-based fire extinguishers, ammonium phosphate dry powder fire extinguishers, foam fire extinguishers, or halon fire extinguishers should be used. 4.2.2 For Class B fire hazards, foam extinguishers, sodium bicarbonate dry powder extinguishers, ferric phosphate dry powder extinguishers, carbon dioxide extinguishers, water-based extinguishers designed for Class B fires, or halon extinguishers should be selected. In Class B fire areas with highly flammable substances, fire extinguishers resistant to solvents and suitable for Class B fires should be selected. 4.2.3 For Class C fire sites, phosphate ammonium salt dry powder fire extinguishers, sodium bicarbonate dry powder fire extinguishers, carbon dioxide fire extinguishers, or halon fire extinguishers should be selected. 4.2.4 For Class D fire areas, special extinguishers designed for extinguishing metal fires should be used. 4.2.5 For Class E fire locations, iron phosphate dry powder fire extinguishers, sodium bicarbonate dry powder fire extinguishers, halon fire extinguishers, or carbon dioxide fire extinguishers should be used. Carbon dioxide fire extinguishers equipped with metal nozzle nozzles shall not be used. Gas fires are classified as Class C fires; according to the regulations, dry powder fire extinguishers containing phosphoric acid salts, sodium bicarbonate dry powder fire extinguishers, carbon dioxide fire extinguishers, or halon fire extinguishers should be used. The above information is for reference only!

Water cannot be used to extinguish fires involving flammable and combustible gases; so what should be chosen in such cases? What reason!

I choose AB; I don’t dare choose C, and I’m not sure about D. Dry powder fire extinguishants are those currently used in our company; they can be used to put out fires involving flammable oils. I learned about CO2 in school before – it’s expensive, but it has a wide range of applications.

The answer is ABD; C cannot be chosen. The 1211 fire extinguisher uses the pressure of nitrogen contained within the cylinder to spray out the 1211 extinguishing agent in order to put out fires. It belongs to the pressure-storage type. 1211 is the code for dichlorodifluorobromomethane, with the molecular formula CF2ClBr. It is the most widely used halogenated hydrocarbon extinguishing agent in China at present, and it is stored in liquid form inside steel cylinders. 1211 fire extinguishing agent is a liquefied gas with a low boiling point, offering advantages such as high fire extinguishing efficiency, low toxicity, low corrosivity, stability over long storage periods, no residue after use, no contamination of the protected items, and good insulating properties. 　　The 1211 fire extinguisher is mainly suitable for extinguishing incipient fires involving flammable and combustible liquids, gases, and energized equipment ； Extinguishing incipient fires involving precision instruments, meters, valuable materials, precious cultural relics, books, archives, etc ； Extinguishes incipient surface fires of solid materials in locations such as airplanes, ships, vehicles, oil depots, and hotels. 　　MY type portable 1211 fire extinguisher: 1. Specifications: Based on the amount of extinguishing agent contained, it is available in six models with capacities of 0.5 kilograms, 1 kilogram, 2 kilograms, 3 kilograms, 4 kilograms, and 6 kilograms. 　　2. Usage: To use it, first remove the safety pin, then grip the trigger to spray. 　　It should be noted that when extinguishing a fire, the device must be kept in an upright position; it should not be used horizontally or upside down. The nozzle should be directed at the base of the flame, and moved forward quickly, from near to far ； To prevent the rekindling of tempering, sporadic small fires can be extinguished by spot shooting. In the event of a flammable liquid burning inside a container, the jet of 1211 fire extinguishing agent can be directed from top to bottom toward the inner walls of the container. When extinguishing a fire on the surface of a solid material, aim the nozzle at the most intense part of the fire and spray back and forth. 　　3. Maintenance 　　a. It should be stored in a well-ventilated, dry place that is easy to access, with the storage environment temperature ranging from –10°C to 45°C. 　　b. It must not be stored near heating or warming equipment or in areas with strong sunlight, to prevent deterioration and loss of effectiveness. 　　c. Check the pressure on the fire extinguisher every six months; if the gauge pointer is in the red area, the extinguishing agent and nitrogen should be replenished immediately. 　　d. A hydrostatic test at 1.5 times the design pressure shall be conducted every five years or before refilling the fire extinguishing agent, and use may continue only upon passing such test. 　　Provisions for the Disposal of 1211 Fire Extinguishers 1 Scope This standard specifies the methods for assessing the suitability of 1211 fire extinguishers for disposal. This standard applies to portable 1211 fire extinguishers and wheeled 1211 fire extinguishers (hereinafter referred to as fire extinguishers). 　　2 Normative reference documents The provisions in the following documents become provisions of this standard through reference to it. For any referenced documents dated, all subsequent amendments (excluding corrections) or revised versions thereof are not applicable to this standard; however, parties reaching an agreement under this standard are encouraged to consider whether the latest versions of such documents can be used. For reference documents without a date, the latest version applies to this standard. 　　GB4351--1997 General technical requirements for portable fire extinguishers GB8109--87 Performance requirements and test methods for wheeled fire extinguishers GB12137-89 Test methods for the airtightness of gas cylinders 3 Terms and definitions The following terms and definitions apply to this standard. 　　3.1 Maintenance Inspection Maintenance inspection is a check carried out using simple visual methods; it represents the most basic assessment of whether a fire extinguisher can still be used. 　　3.2 Servicing Inspection Servicing inspection refers to the checks carried out before refilling and the regular inspections during use; it is a check designed to determine whether the fire extinguisher can continue to be used safely and effectively. 　　4 Inspection Items and Inspection Periods 4.1 Inspection Items 4.1.1 Maintenance inspection items include: Inspection of the external structure and accessories ； 　　Inspection of external corrosion degree of the cylinder body ； 　　Flag check and leak check. 　　4.1.2 Maintenance inspection items include: Inspection of external and internal structures and components ； 　　Inspection of corrosion degree on the outside and inside of the cylinder ； 　　Inspection of the pressure test and airtightness test for the cylinder and valves. 　　4.2 Inspection Period 4.2.1 Maintenance Inspection Period Fire extinguishers should undergo a maintenance inspection at least once a year. 　　4.2.2 Maintenance and inspection cycle The maintenance and inspection cycle shall be determined as follows: a) After a fire extinguisher has been opened or used, or if it has not been used for 5 years from the date of manufacture indicated on it, it should be taken to a qualified maintenance facility (hereinafter referred to as a maintenance unit) for maintenance and inspection ； 　　b) Fire extinguishers that have been repaired should be taken back to the repair facility for another inspection every two years thereafter ； 　　c) When a fire extinguisher shows one of the following conditions, it should be sent to a maintenance facility for repair and inspection in advance: the safety device has been damaged ； The pressure gauge indicates the red zone, or the pressure gauge is in the green zone but the weight of the fire extinguisher has decreased significantly ； The pressure indicator is damaged ； When the cylinder is dented, scratched, severely corroded, or other components are severely damaged ； The repaired sign does not have a repair date. 　　5　Disposal Assessment 　　5.1　Disposal Assessment Based on Maintenance Inspections A fire extinguisher should be disposed of if any of the following conditions are found during maintenance inspections: 　　a) The coating on the exterior of the cylinder is damaged or the area of rusting is equal to or greater than one-third of the total surface area of the cylinder ； 　　b) No pressure indicator ； 　　c) The cylinder shows visible deformation ； 　　d) Visible cracks on the instrument tip ； 　　e) The instructions for use are unclear or incomplete ； 　　f) The base becomes ineffective due to cracking, wear, or corrosion ； 　　g) Severe corrosion of metal parts such as the pressure handle of the fire extinguisher and valves ； 　　h) No production date ； 　　i) No production license or no certification or approval mark ； 　　j) Non-metallic tool head ； 　　k) More than 10 years have passed since the production date indicated on the label ； 　　l) Fire extinguishers repaired by unlicensed repair units ； m) When its use is explicitly prohibited by laws or regulations. 　　5.2 Evaluation for Disposal Based on Maintenance Inspections: A fire extinguisher should be disposed of if any of the following conditions are found during maintenance inspections: a) A fire extinguisher with one of the defects listed in section 5.1 ； 　　b) The valve cannot be opened ； 　　c) No pressure relief structure ； 　　d) The results of the hydrostatic pressure tests on the cylinder and nozzles of portable 1211 fire extinguishers do not meet the requirements of clause 5.10.1.1 in GB4351-1997, or the results of such tests on the cylinder and nozzles of wheeled 1211 fire extinguishers do not meet the requirements of clause 3.7.3 in GB8109-87 ； 　　e) When conducting a airtightness test in accordance with the requirements of GB12137-89, leakage occurs in the cylinder or valve at a test pressure equal to the maximum operating pressure (PMS) of the fire extinguisher ； 　　f) Rust flakes inside the cylinder or pits of rust on the internal surface ； 　　g) The depth of dents, scratches, pits, and linear or surface corrosion on the outside of the cylinder is greater than or equal to 10% of the designed wall thickness (see Appendix A for the measurement method). 　　6 Disposal after retirement Fire extinguishers deemed retired should be sent to a legitimate recycling facility for disposal. The remaining 1211 fire extinguishing agent should be recovered. 　　The cylinders of discarded fire extinguishers should be destroyed by recycling units. The methods of destruction are crushing, punching, or sawing. 　　7. Scope of application for halogenated alkane 1211 fire suppression systems: Applicable to fires involving combustible gases such as methane, ethane, propane, gas, and natural gas ； 　　2) Fires involving liquid hydrocarbons, alcohols, aldehydes, ketones, ethers, benzenes, and other similar liquids ； 　　3) Initial fires in paper, wood, and textiles; surface fires in combustible solids such as plastics and rubber ； 　　4) Electrical fires in transformers, generators, motors, power distribution and transformation equipment, etc.

Class 2 B fires: Fires involving liquids or fusible solid materials. 3 Class C fire: Gas fire. 4.2.2 For Class B fire hazards, foam extinguishers, sodium bicarbonate dry powder extinguishers, ferric phosphate dry powder extinguishers, carbon dioxide extinguishers, water-based extinguishers designed for Class B fires, or halon extinguishers should be selected. In areas classified as Class B fire hazards involving polar solvents, fire extinguishers that are effective against Class B fires and that are resistant to solvents should be used. Water-based fire extinguishers for Class B fires are also an option; I’ve never heard of them before though

Apart from water, everything else can be used to extinguish oil, flammable, combustible, and gas fires.