Water is the most common fire extinguishing agent in our impression. When a fire occurs, using water to put it out may be the first reaction for most people. But do you know that using water to extinguish some fires may actually "add fuel to the fire"? Which fires are not compatible with water?
Gasoline Fire
Because gasoline has a lower specific gravity than water, if water is used to extinguish it, the gasoline will float on the water and continue to burn. As the water spreads, the burning area expands, endangering the safety of other goods and surrounding structures.
Correct method: Use carbon dioxide or dry powder fire extinguishers to extinguish gasoline fires. Dry sand can also be used.
Alcohol Fire
If alcohol is on fire, pouring water on it will only make it continue to burn and not achieve immediate extinguishing. This is because alcohol will still burn after being dissolved in water, and the burning area will expand as the water spreads. It is very dangerous.
Correct method: If it is not a person on fire, carbon dioxide or dry powder fire extinguishers can be used. Dry sand can also be used. If it is a person on fire, use a blanket to cover them. It is best not to use a fire extinguisher as it can be inhaled and cause injury.
Cooking Oil and Paint Fire
Cooking oil, as well as oil-based paints and solvents used in decoration, such as banana water, are organic solvents or contain organic solvents. Once they ignite, they cannot be extinguished with water. The reason is that the specific gravity of these solvents is smaller than that of water. After pouring water, the water cannot cover them but quickly runs underneath them, failing to isolate oxygen.
In addition, pouring water will increase the contact area between these organic solvents and air, making the fire burn more vigorously. At high temperatures, water will boil and vaporize rapidly, and may even splash the burning organic solvents around like an explosion.
Method: If a pot of oil catches fire, wear cotton gloves, quickly turn off the gas, and immediately cover the pot with a lid. After the oxygen in the pot is exhausted, the fire will be extinguished immediately. If a gas cylinder sprays fire, also wear cotton gloves and immediately tighten the valve to extinguish the fire.
In addition to large cotton gloves, a cotton quilt is also a useful tool for extinguishing fires. If the fire is not too big, just cover it with a cotton quilt. Small fires will not immediately raise the temperature of the cotton fibers to the burning point, but the cotton quilt can isolate oxygen and prevent the fire from igniting. It is worth noting that the cotton quilt should not be uncovered immediately to prevent any remaining sparks from reigniting when exposed to oxygen.
Old Electrical Appliances Fire
Due to issues such as excessive service life and improper use, old electrical appliances are prone to short circuits and fires. At this time, never use water to extinguish the fire. The reason is that the electrical appliances are still connected to the power source, and water can conduct electricity, which may cause accidental electric shock. In addition, when old electrical appliances are doused with water, they may explode due to a sudden drop in temperature.
Handling method: When encountering an electrical appliance fire, the first thing to do is to cut off the power supply. If there is a fire near the electrical appliance and it is not convenient to approach and unplug the power supply, cut off the main switch in the house, and then proceed with extinguishing the fire using water or covering it with a cotton quilt.
Chemical Fires with Potassium, Sodium, Magnesium, etc.
When storing chemicals such as potassium, sodium, magnesium, aluminum powder, carbide, quicklime, sodium peroxide, as well as strong acids such as sulfuric acid and hydrochloric acid, water should not be used to extinguish fires. The reason is that these substances can react with water, which may generate a large amount of heat energy and cause the fire to burn more vigorously.
On the other hand, the reaction may also produce flammable gases, increasing the risk of explosion. Strong acids themselves do not burn, but they will quickly splash around when they encounter water, corroding the surrounding environment and rescue personnel. Therefore, in such situations, it is best to carefully choose fire extinguishing materials, extinguish the external fire first, and then investigate the internal situation. The dangerous substances should be removed at low temperatures.
