The situation when gasoline catches fire is one of the most dangerous and requires an immediate response. The speed of flame spread in this case is calculated in seconds, and the consequences can be catastrophic for human life and property. Understanding that How can you put out gasoline?, and what actions will only aggravate the situation should be known to everyone who owns a car or works with fuel and lubricants. Knowledge of the physics of combustion of liquid hydrocarbons allows you to act calmly and efficiently.
The main difficulty is that gasoline is a light liquid that is lighter than water and does not mix with it. When you try to put out the flame with ordinary water, gasoline floats to the surface, continuing to burn and spreading, increasing the area of the fire. This is why classical methods of fighting fire do not work here or are even dangerous. In the article we will analyze in detail the chemical and mechanical methods of localizing the outbreak, and also explain why class B fire extinguishers are a priority.
It is important to note that the effectiveness of extinguishing directly depends on the volume of spilled fuel and environmental conditions. In the open air, the wind can quickly spread the burning mixture, making local methods pointless. In enclosed spaces such as a garage, the concentration of vapors and the risk of explosion become a critical factor. The main rule when large volumes of gasoline catch fire is to immediately leave the danger zone and call the fire department without trying to be a hero.
The physics of gasoline combustion and why water doesn't work
To understand how to effectively fight fire, you need to understand the combustion mechanism of gasoline. The process is supported by three factors: the combustible substance, the oxidizing agent (oxygen) and the ignition temperature. Gasoline has a low flash point, and its vapor mixed with air burns first. The goal of firefighting is to break this chain by cutting off oxygen or cooling the substance below the critical point.
Trying to use water to extinguish gasoline often has the opposite effect due to the difference in density. The density of gasoline is about 0.7–0.75 g/cm³, while water is 1 g/cm³. When a jet of water hits burning gasoline, the following occurs:
- 💧 Water instantly sinks to the bottom of a tank or puddle, displacing burning gasoline to the top.
- 🔥 There is a sharp splashing of the burning liquid, which increases the combustion area several times.
- 🌡️ Water can boil upon contact with hot surfaces, causing a steam-gas explosion and scattering of flames.
There are exceptional cases when water is used in the form of a fine mist under high pressure, but this is only possible with the help of specialized fire fighting equipment, which is equipped with professional teams. In domestic conditions or when eliminating the consequences of an accident, the use of buckets of water is strictly prohibited. Not only will this not help, but it will also create an additional threat to the rescuer.
⚠️ Attention: Never spray water onto burning gasoline. This will lead to instant spreading of the burning liquid and burns to the legs.
Powder fire extinguishers: a universal remedy
The most accessible and common means of fighting petroleum product fires are powder fire extinguishers, labeled as OP (powder fire extinguisher). They belong to the class B (flammable liquids) and C (flammable gases). The principle of their operation is based on isolating the combustion site from oxygen using an inert powder, which is also capable of inhibiting the chemical combustion reaction.
To use such a device, it is necessary to break the seal, pull out the pin and point the bell at the base of the flame, and not at its top. Pressing the lever releases a cloud of fine powder that envelops the burning surface. It is important to hold the fire extinguisher vertically and maintain a distance of 2-3 meters so that the wind does not blow the powder back into your face.
However, powder fire extinguishers have their drawbacks that you should be aware of:
- 🌫️ The powder creates a dense cloud that sharply reduces visibility, which can be disorienting in a smoky room.
- 🧹 After use, complex and lengthy cleaning of the car interior or room from fine dust is required.
- 🔄 The powder does not have a cooling effect, so re-ignition from smoldering objects is possible.
Despite the polluting properties, OP-2 or OP-4 remain the standard for automobiles due to their low cost and ability to quickly extinguish flames. When extinguishing, it is important to act quickly, since the effective stream time for small cylinders is only 10–15 seconds.
Carbon dioxide fire extinguishers and their features
Carbon dioxide fire extinguishers (marking Op-amp) are considered a more effective and cleaner extinguishing agent for gasoline, especially in confined spaces such as the engine compartment or garage. They are filled with liquefied carbon dioxide (CO2), which expands sharply upon release, cooling to a temperature of -60..-70°C. This allows not only to displace oxygen, but also to significantly cool the burning surface.
Main advantage Op-amp Compared to powder analogues - lack of contamination. After use, carbon dioxide simply evaporates, leaving no traces on the engine, wiring or upholstery. This makes them ideal for extinguishing electrical installations with voltages up to 1000 V, which is often relevant in modern cars with electronics.
However, when using carbon dioxide fire extinguishers, strict precautions must be taken:
- 🥶 It is strictly forbidden to handle the bell with bare hands - the temperature during operation drops to extremely low values, and severe cold burns are possible.
- 🌬️ In small, unventilated spaces, high CO2 content can cause suffocation in people.
- 💨 The gas stream has a strong reactive impulse, which requires a strong hold of the cylinder.
When extinguishing with a carbon dioxide fire extinguisher, hold the bell only by the special handle, even if it seems cold in appearance.
The effectiveness of carbon dioxide is higher than that of powder due to the combined effect: the inert gas is heavier than air and tightly “covers” the fire, and sudden cooling prevents the re-flare of vapors.
Foam and air-foam fire extinguishers
Foam fire extinguishers (marking ORP) are designed specifically for extinguishing flammable liquids, including gasoline, diesel fuel and oils. The principle of their operation is the formation of a dense film of foam on the surface of the burning liquid. This film performs two functions: it isolates the fuel from oxygen and prevents the release of new vapors.
Unlike powder, foam does not rise into the air, but lies in an even layer, filling all surface irregularities. This is especially important when extinguishing a gasoline spill on a garage floor or asphalt. The foam also has some cooling effect, as it contains up to 90% water in a bound state, but does not flow as aggressively as pure water.
Comparative table of the effectiveness of various types of fire extinguishers when extinguishing gasoline:
| Fire extinguisher type | Effective against gasoline | Cleanability | Cooling effect |
|---|---|---|---|
| Powder (OP) | High | Low (dirty) | Missing |
| Carbon dioxide (CO) | Very high | Excellent | High |
| Foam (ORP) | High | Average | Medium |
| Water (OW) | Low/Dangerous | High | High |
It is worth considering that foam fire extinguishers cannot be used to extinguish live electrical equipment, since foam conducts electricity. If gasoline ignites in the area of open electrical contacts, you must first turn off the power or use a carbon dioxide/powder apparatus.
Mechanical methods and improvised means
In situations where there is no specialized fire extinguisher at hand, mechanical methods of isolating the fire from oxygen can be useful. The most famous method is to throw a thick fabric that does not support combustion onto the fire. Ideal for these purposes asbestos blanket or felt, which can often be found in professional workshops.
At home, you can use thick woolen fabric, a tarpaulin, or even a heavy jacket, pre-moistened with plenty of water. The fabric must be covered with a sharp movement, pressing the edges to the ground to block the flow of air. The effectiveness of this method depends on the speed of the reaction and the size of the lesion.
Another effective remedy is sand or soil. They work on the principle of insulation and partial cooling:
- 🏖️ Sand is non-flammable and heavier than gasoline, so it sinks and blocks the access of oxygen.
- 🚜 The soil is only effective if it is wet; dry dust can, on the contrary, create an explosive mixture in the air.
- 🧱 Using salt or soda is also possible in small volumes (for example, when burning in a bucket), since when heated they release gases that displace oxygen.
☑️ Actions in case of gasoline fire
If gasoline is spilled over a large area, covering it with sand will be ineffective and time-consuming.
Critical errors and prohibited actions
Panic and ignorance of the physics of the process often lead to actions that turn a local fire into a large-scale disaster. The most common and fatal mistake is trying to put out the flames with water from a hose or bucket. As already mentioned, this leads to the spreading of a burning film of gasoline over the entire surface, including the clothes of the rescuer.
Another dangerous mistake is using dry washing powder in large quantities. Although some components can chemically inhibit combustion, a cloud of dust from the powder mixed with gasoline vapor can trigger a volumetric explosion. Also, do not try to extinguish gasoline by slapping it with a rag or blanket - this saturates the fire with oxygen, intensifying the combustion.
⚠️ Attention: Never turn your back to an extinguished fire until you are sure that the temperature has dropped and no more fumes are being released.
It is also dangerous to use fusible containers or materials for extinguishing, which themselves can catch fire or melt by adding a flammable substance to the fire. All actions should be aimed at isolation, and not at inflating or stirring the burning mass.
Algorithm of actions in case of car fire
If gasoline catches fire in a car, seconds count. The first action should be to immediately stop, turn off the engine and evacuate all passengers to a distance of at least 50 meters. Only after this, if the fire is small and it is possible to approach, you can try to use a fire extinguisher.
When extinguishing the engine compartment, you cannot open the hood completely, as a sudden influx of oxygen will cause a flash. It is necessary to open the hood, insert the fire extinguisher nozzle into the slot and fire a salvo. If a flame breaks out, it is forbidden to open the hood - you need to extinguish it through the cracks or use sand/earth.
What to do if a fuel tanker or large tank catches fire?
In this case, it is strictly forbidden to approach. It is necessary to immediately leave the place at a distance of at least 300-400 meters, as a vapor explosion is possible. Tell the emergency dispatcher the exact location and type of cargo.
If
The most important thing in case of a gasoline fire is not to use water and not to completely open air access to the fire without an extinguishing agent.
FAQ: Frequently asked questions
Is it possible to extinguish gasoline with soda?
Yes, baking soda (sodium bicarbonate) can be used to extinguish small gasoline fires. When heated, it releases carbon dioxide, which displaces oxygen. However, large volumes of fuel will require too much baking soda and this method is ineffective compared to a fire extinguisher.
Why can't you extinguish gasoline with water?
Gasoline is lighter than water and does not mix with it. When you try to douse the fire with water, gasoline floats to the surface and continues to burn, spreading along with the water and increasing the area of the fire. This poses a risk of fire expansion and burns.
What is the best fire extinguisher to have in your car?
The best option is a powder fire extinguisher (OP-2 or OP-4) or carbon dioxide (OU-2). Powder is cheaper and more versatile, but it stains the interior. Carbon dioxide is cleaner and cools more efficiently, but is more expensive and requires caution when used due to the low temperature of the jet.
What to do if gasoline catches fire on your clothes?
It is necessary to immediately knock the person down so that the flame does not rise to the head, and cover the burning area with thick fabric (blanket, jacket), cutting off the access of oxygen. Rolling on the ground also helps put out the flames. Water should only be used if it will not cause large amounts of fuel to spread.
Is sand effective for extinguishing gasoline?
Yes, sand is very effective as it isolates the fuel from oxygen and does not react. It is best to use wet sand. However, you need to fill it generously, completely cutting off the access of air to the burning liquid.