The National Fire Protection Association (NFPA) has issued three gas station safety tips: Not overfill your tank when the gas pump shuts off, which could cost you an expensive repair and potentially damage the evaporative (or charcoal) canister used to capture gasoline vapors and keep emissions within specs. Don't smoke, vape, or use a lighter near fuel pumps, as these are highly flammable materials that could ignite a fire or cause an explosion. Gas station fires are rare as most fueling stations have measures in place to limit the amount of gasoline vapor in the air. However, if gasoline vapor concentrations are between 1.4% and 7.6% in the atmosphere, these incidents can lead to life-threatening situations. The primary cause of these fires is usually gasoline vapor, which evaporates easily and is invisible, flammably, invisible, and three to four times denser than air. Not using electronics while fueling, or leaving your vehicle while refueling, could cause injury, swelling, and first- and second-degree skin burns. The most common mistake is leaving your car's engine on the engine running while filling up, increasing the risk of igniting a fire.