[Q&A Question 289] 2017.11.3

1. Cut off the gas supply. 2. Implement on-site control. 3. Contain the source of fire. 4. Improve ventilation. 5. Seal the leak site. 6. Extinguish the fire. When a fire breaks out due to a hydrogen leak, after cutting off the gas supply, preparing to seal the leak, and containing the flames, the fire can be extinguished using dry powder; thereafter, the leak should be sealed promptly, while continuing to cool the equipment until its temperature returns to normal. During fire fighting and emergency response, it is important to note that hydrogen flames are hard to detect; rescuers should protect their exposed skin from burns. The hydrogen system should be kept under positive pressure as much as possible to prevent backfire, which could lead to a fire or explosion in the entire hydrogen pipeline system. As long as the gas supply has not been cut off and it is not certain that the leak has been sealed, firefighters should intensify the cooling of the tanks that are on fire as well as the adjacent tanks and related pipelines, in order to keep the fire under control and allow it to burn steadily. For adjacent storage tanks, it is advisable to focus cooling on the side exposed to flame radiation. At the same time, the tank on fire should be emptied to reduce the pressure inside it and prevent explosions. It is absolutely not allowed to completely extinguish the flame while the leakage points have not been properly addressed and hydrogen is still escaping; otherwise, after the flame is extinguished, the hydrogen leakage could lead to the formation of an \"explosive gas cloud\", resulting in a catastrophic explosion with unimaginable consequences. When the vent valve of the storage tank or a leak point releases gas violently, accompanied by a loud hissing sound, vibrations of the tank, and white flames, these are signs of an impending explosion; personnel on site must immediately evacuate or take cover, and all people in the vicinity should also be evacuated swiftly.

Determine the location and severity of the leak, and cut off the source of leakage while ensuring personal safety. 　　　　 Quickly close the hydrogen valve, eliminate any open flames in the vicinity, and shut down all engines and electrical equipment nearby. Stop all operations around that may generate sparks, evacuate personnel, avoid air currents, and quickly move to an upwind area.

Evacuate people from the contaminated area promptly to a safe zone, isolate it, and strictly restrict access. Cut off the source of fire. It is recommended that emergency responders wear self-contained positive-pressure breathing apparatus and fire protection clothing. Seal the source of the leak as much as possible. Prevent entry into confined spaces such as sewers and drainage ditches. Minor leaks: Absorb with sand, vermiculite, or other inert materials. Or, if safety permits, burn it on the spot. Large-scale leakage: Build dikes or dig pits to contain it; cover it with foam to reduce vapor hazards. Transfer to a tank truck or specialized collector using an explosion-proof pump, and recycle it or transport it to a waste disposal facility for disposal.

Identify the location of the leak and its severity, and shut off the source of the leak while ensuring personal safety. 　　　　 Quickly close the hydrogen valve, eliminate any open flames in the vicinity, and shut down all engines and electrical equipment nearby. Stop all operations around that may generate sparks, evacuate personnel, avoid air currents, and quickly move to an upwind area.

1. Adhere to the tactical principles of \"evacuating and rescuing people, demarcating areas, handling matters in an orderly manner, and ensuring safety\"； 2. Control and eliminate all potential sources of danger that could cause an explosion ； 3. Strictly control access to the site, assemble a capable team, and ensure proper safety measures as well as cover for operations ； 4. Choose the correct route for movement, direction of attack, and deployment of combat forces ； 5. Make full use of fixed facilities and adopt process measures for disposal ； 6. Establish a command post in safe areas such as upwind or side-upwind positions, and use communication and broadcasting methods to ensure effective coordination and command ； 7. Closely monitor potential dangers, and take decisive action for attack or evacuation ； 8. Conduct a thorough inspection, clean up completely, eliminate potential hazards, and ensure proper handover.

Determine the location and severity of the leak, and cut off the source of leakage while ensuring personal safety. 　　　　 Quickly close the hydrogen cylinder valve, eliminate any open flames in the vicinity, and shut down all engines and electrical equipment nearby. Stop all operations around that may generate sparks, evacuate personnel, avoid air currents, and quickly move to an upwind area.

(1). Alert and establish a perimeter. Evacuate people from the area where the leak has occurred to areas upwind promptly, isolate the zone by setting up warning lines and clear signs, inform the people inside and around that area to evacuate immediately, and prohibit vehicles and unauthorized persons from entering the restricted area. (2). Immediately cut off the source of the leaking gas. And quickly evacuate people from the contaminated area to an upwind location. Leak sealing should be carried out while ensuring safety, and anti-static tools must be used for emergency repair work. Persons entering the leak area must wear anti-static clothing and self-contained breathing apparatus. (3). Eliminate ignition sources. Stop all operations involving fire and eliminate any activities that may generate sparks; it is prohibited to strike equipment pipes to prevent sparks from arising due to friction or impact ； Use a water gun equipped with a spray function to discharge fire-fighting water at the leaking tank wall and the area where the leak occurs, in order to lower the temperature at the scene as well as the temperature of the leaking equipment. (4). Pressure relief discharge. With the process flow in good order, the hydrogen gas inside the container is discharged through the discharge line to the emergency flare pipeline. (5). Dilute the hydrogen in the leakage area. Ventilate the area contaminated by the leak; if the leak cannot be stopped promptly, steam should be used to dilute the atmosphere and prevent hydrogen from accumulating to form an explosive gas mixture. (6). If the leak occurs indoors, it is advisable to use an exhaust system to remove the leaked hydrogen outside and to ventilate the indoor area to replace the air. The hydrogen concentration in the dilution chamber is reduced to prevent the accumulation of hydrogen that could form an explosive gas mixture; explosion-proof electrical equipment is used in the ventilation system. (7). High concentrations of hydrogen gas can cause suffocation; the affected person should be promptly moved to a well-ventilated area, given artificial respiration, and taken to a medical facility as soon as possible

Call the police and set up a perimeter； Immediately cut off the source of the leaking gas ； Eliminate sparks ； Pressure relief discharge ； Dilute the hydrogen in the leak area and ventilate the contaminated zone ； If the leak occurs indoors, it is advisable to use an exhaust system to remove the leaked hydrogen outside and to ventilate the indoor area to replace the air ； High concentrations of hydrogen gas can cause asphyxiation; the affected person should be moved to a well-ventilated area promptly

Determine the location and severity of the leak, and cut off the source of leakage while ensuring personal safety. Isolate the area where air is leaking to prevent unauthorized personnel from entering. After evacuation, before entering the area where air leakage occurs, it is necessary to ventilate that area properly in advance to accelerate the dispersion of air and ensure personal safety. Leaking tanks must be properly handled, repaired, and inspected before being reused.

1. In the event of a large-scale leak, the following measures should be taken immediately: (1) Alert the authorities and establish a safety zone. Evacuate people from the area where the leak has occurred to areas upwind promptly, isolate the zone by setting up warning lines and clear signs, inform the people inside and around that area to evacuate immediately, and prohibit vehicles and unauthorized persons from entering the restricted area. (2). Immediately cut off the source of the leaking gas. And quickly evacuate people from the contaminated area to an upwind location. Leak sealing should be carried out while ensuring safety, and anti-static tools must be used for emergency repair work. Persons entering the leak area must wear anti-static clothing and self-contained breathing apparatus. (3). Eliminate ignition sources. Stop all operations involving fire and eliminate any activities that may generate sparks; it is prohibited to strike equipment pipes to prevent sparks from arising due to friction or impact ； Use a water gun equipped with a spray function to discharge fire-fighting water at the leaking tank wall and the area where the leak occurs, in order to lower the temperature at the scene as well as the temperature of the leaking equipment. (4). Pressure relief discharge. With the process flow in good order, the hydrogen gas inside the container is discharged through the discharge line to the emergency flare pipeline. (5). Dilute the hydrogen in the leakage area. Ventilate the area contaminated by the leak; if the leak cannot be stopped promptly, steam should be used to dilute the atmosphere and prevent hydrogen from accumulating to form an explosive gas mixture. (6). If the leak occurs indoors, it is advisable to use an exhaust system to remove the leaked hydrogen outside and to ventilate the indoor area to replace the air. The hydrogen concentration in the dilution chamber is reduced to prevent the accumulation of hydrogen that could form an explosive gas mixture; explosion-proof electrical equipment is used in the ventilation system. (7). High concentrations of hydrogen gas can cause suffocation; the affected person should be promptly moved to a well-ventilated area, given artificial respiration, and taken to a medical facility as soon as possible