Gasoline fires cannot be put out with water. Gasoline is lighter than water, so pouring water on a burning pool of gas simply spreads the fuel outward, making the fire larger and more dangerous. The correct approach depends on the size of the fire: small gasoline fires can be smothered or extinguished with the right type of fire extinguisher, while large or spreading fires require immediate evacuation and a call to 911.
Why Water Makes Gasoline Fires Worse
This is the single most important thing to understand. Gasoline floats on water. When water hits a burning pool of gasoline, the fuel rides on top and flows wherever the water goes, carrying flames with it. On a flat surface like a garage floor or driveway, water pushes the burning gasoline outward, endangering a much larger area and anyone standing nearby.
There’s a second problem: water hitting the extreme heat of a gasoline fire can flash into steam almost instantly. That rapid expansion can splash burning fuel into the air, throwing flaming droplets in unpredictable directions. This is why gasoline fires are classified as Class B fires (flammable liquids), which require smothering rather than dousing.
Smothering a Small Gasoline Fire
Fire needs oxygen. If the gasoline fire is small and contained, like a spill in a metal pan or on a limited patch of concrete, cutting off its air supply is the fastest way to kill it. A metal lid, a cookie sheet, or a large piece of sheet metal placed directly over the flames can do the job. The key is covering the entire surface of the burning liquid so no oxygen reaches it. Do not lift the cover to check. Let the area cool for several minutes before removing it, because the gasoline vapor underneath can reignite the moment air returns.
Sand or dirt also works for very small spills. A thick layer dumped on top absorbs the fuel and blocks oxygen simultaneously. This is why many workshops and gas stations keep a bucket of sand nearby.
Choosing the Right Fire Extinguisher
For anything beyond a tiny spill, a fire extinguisher rated for Class B fires is the safest tool. There are two main types that work on gasoline.
- Dry chemical extinguishers: These spray a fine powder (typically based on sodium bicarbonate or potassium bicarbonate) that coats the burning liquid and smothers the flames. Multipurpose dry chemical extinguishers, sometimes labeled ABC, use a different powder but work the same way on gasoline. These are the most common household and garage extinguishers, and they’re effective on gasoline fires.
- CO2 extinguishers: These displace oxygen around the fire with a blast of carbon dioxide gas. They’re rated for Class B and Class C (electrical) fires. CO2 leaves no residue, which makes cleanup easier, but it’s less effective outdoors where wind disperses the gas quickly.
Before you buy or grab an extinguisher, check the label. Extinguishers rated only for Class A fires (ordinary combustibles like wood and paper) use pressurized water. Using one on a gasoline fire will spread the flames exactly like a garden hose would.
How to Use the Extinguisher
Stand 6 to 8 feet from the fire, upwind if possible. Use the PASS method: pull the pin, aim the nozzle at the base of the flames (not the tops), squeeze the handle, and sweep side to side across the fire’s base. Most portable extinguishers empty in 10 to 20 seconds, so you need to be deliberate and efficient. If the fire doesn’t shrink noticeably within a few seconds, stop, get out, and call 911.
What to Do With a Vehicle Gasoline Fire
A car fire involving the fuel system escalates fast. If you see flames or heavy smoke coming from under the hood or near the fuel tank, do not open the hood or trunk. Opening it feeds the fire a rush of fresh oxygen and can cause it to grow dramatically.
The U.S. Fire Administration recommends pulling over, turning off the engine, getting everyone out of the vehicle, and moving at least 100 feet away. That distance matters because vehicle fires can reach fuel lines, tires, and other components that may rupture or explode. Call 911 from that safe distance. A vehicle gasoline fire is not something to fight with a small portable extinguisher unless the fire is still very small and clearly contained to one area.
If Gasoline Gets on Your Skin or Clothing
Burning gasoline that contacts skin causes both thermal and chemical burns. If your clothing catches fire, stop, drop, and roll to smother the flames. Once the fire is out, remove any clothing that has gasoline on it, because the fuel can reignite or continue causing chemical damage to skin.
Rinse the burned area with cool running water for at least 20 minutes. Do not use ice, butter, or ointments. If the burn is deep, larger than about 3 inches across, or covers the hands, feet, face, or any joint, it needs emergency medical care. Cover the burned area loosely with clean gauze or cloth while waiting for help. Watch for signs of shock: cool and clammy skin, a weak pulse, or shallow breathing.
Preventing Gasoline Fires
Most gasoline fires start not from the liquid itself but from its vapor, which is heavier than air and pools invisibly at ground level. A spark from a light switch, a static discharge, or a running engine can ignite vapor from a gas can sitting open several feet away.
Store gasoline only in approved containers with tight-fitting lids. Never use gasoline near open flames, pilot lights, or running equipment. If you spill gasoline, ventilate the area immediately by opening doors and windows, and don’t turn any electrical switches on or off until the vapor clears. Keep a dry chemical extinguisher rated for Class B fires anywhere you store or handle gasoline, whether that’s a garage, workshop, or utility shed.