Both gasoline and kerosene originate from crude oil, but they are separated and refined at different temperatures, resulting in fundamentally distinct characteristics. The clear answer is that kerosene does not explode in the same manner as gasoline, which is a key difference in their safety profiles. This distinction is rooted in the fuels’ molecular structures, which dictates their volatility and how easily they transition from a liquid to an ignitable vapor state. While gasoline is highly volatile for internal combustion engines, kerosene is a heavier product designed for uses like heating and jet fuel, where controlled burning is preferred.
The Key Metric: Understanding Flash Point and Vapor
The explosiveness of any flammable liquid is determined by the vapor it produces when mixed with air, not the liquid itself. A liquid fuel will only ignite or explode when its vapor concentration falls within a specific range, known as the Flammability Limits, and is exposed to an ignition source. The “Flash Point” is the metric defining the lowest temperature at which a liquid produces enough vapor to form an ignitable mixture near its surface. Below this temperature, there is insufficient vapor for a combustion event to occur. A lower flash point means a substance is more volatile and presents a higher risk of fire or explosion.
Why Gasoline is Highly Volatile
Gasoline is manufactured to be extremely volatile, a property necessary for it to atomize and ignite quickly within a vehicle engine’s combustion chamber. This high volatility is a direct result of its molecular composition, which consists of lighter, shorter hydrocarbon chains. The rapid evaporation of these molecules means gasoline has an exceptionally low flash point, typically around \(-40^\circ\text{F}\) or \(-40^\circ\text{C}\). This low flash point means gasoline is constantly producing ignitable vapors, even in freezing conditions. In an open container or a poorly ventilated area, the liquid quickly generates a dense, explosive cloud of vapor. This high vapor pressure and rapid evaporation make gasoline a constant and significant explosion hazard.
Kerosene: A Higher Barrier to Combustion
Kerosene is composed of longer, heavier hydrocarbon chains than gasoline, making it far less volatile at ambient temperatures. This difference is why kerosene has a much higher flash point, typically above \(100^\circ\text{F}\) (\(38^\circ\text{C}\)). Below this temperature, kerosene produces minimal vapor and will not easily ignite, even if a flame is applied directly to the liquid surface. At room temperature, kerosene requires an external energy source, such as a wick or a high-pressure spray nozzle, to significantly increase its temperature or create an aerosolized mist to produce enough vapor for ignition. Unlike gasoline, which is a constant vapor risk, kerosene is classified as a combustible liquid because it needs to be heated to create the dangerous vapor state.
Safe Handling and Storage Comparison
The vast difference in volatility between the two fuels dictates their safe handling and storage requirements. Because gasoline produces explosive vapors at all normal temperatures, its storage containers must be tightly sealed and kept in well-ventilated areas, often far from pilot lights or heat sources. Gasoline cans are typically red and must incorporate features to manage internal pressure buildup from constant vaporization. Kerosene, due to its higher flash point, is more stable and does not require the same degree of ventilation to prevent explosive vapor buildup at ambient temperatures. Kerosene is frequently stored in blue safety cans to distinguish it from gasoline. Although less volatile, kerosene must still be stored away from heat sources to prevent it from reaching its flash point, at which time it becomes just as dangerous as gasoline. Mixing the two fuels is extremely hazardous, as adding even a small amount of gasoline significantly lowers the flash point of the kerosene, instantly creating a highly explosive mixture.