Is kerosine more explosive than gasoline?

No. In everyday conditions, gasoline presents a greater explosion hazard than kerosine (kerosene) because it evaporates far more readily and its vapors ignite at much lower temperatures. Kerosine is less volatile and typically burns rather than explodes in open air; however, when heated, confined, or aerosolized, kerosine can form flammable mixtures that ignite violently.

What “explosive” means in the context of fuels

For liquid fuels, “explosive” usually refers to how easily the fuel creates a flammable vapor-air mixture and how rapidly that mixture can ignite and expand, especially in confined spaces. Key factors include volatility (how readily the liquid produces vapor), flash point (lowest temperature at which enough vapor forms to ignite), flammability limits (concentration range in air that burns), autoignition temperature (temperature at which it ignites without a spark), and whether the vapor is confined. Bulk liquid doesn’t explode; it’s the vapor (or a fine mist) that can ignite fast enough to feel explosive.

Gasoline vs. kerosine: how they differ

The points below outline the physical and safety-relevant differences that drive explosion risk for each fuel.

• Volatility and vapor pressure: Gasoline has high vapor pressure and evaporates easily at room temperature, quickly reaching flammable concentrations in air; kerosine has very low vapor pressure and evaporates slowly unless warmed.
• Flash point: Gasoline: about −40°C (−40°F), meaning its vapor is ignitable even in cold conditions. Kerosine: typically 38–72°C (100–162°F), so it generally must be warmed to produce enough vapor to ignite.
• Flammability limits in air (approximate): Gasoline vapor burns between about 1.4% and 7.6% by volume; kerosine vapor roughly 0.7% to 5%—but kerosine’s low volatility makes those levels harder to reach at ambient temperatures.
• Autoignition temperature: Gasoline around ~280°C (~536°F). Kerosine around ~210–245°C (~410–473°F). Kerosine can ignite on hot surfaces more readily when sufficiently vaporized.
• Energy content: Both are similar by mass (about 43–44 MJ/kg). Kerosine is denser, so per liter it carries slightly more energy, but explosion hazard hinges more on vapor formation and ignition conditions than total energy.
• Typical behavior of spills: Gasoline tends to form ignitable vapor clouds quickly, especially in enclosed or low-lying areas; kerosine more often produces a pool fire unless heated, atomized, or poorly ventilated.
• Regulatory class (U.S.): Gasoline is a Class I flammable liquid (Class IB), while kerosine is typically a Class II combustible liquid—reflecting its higher flash point and lower volatility.

Taken together, these factors explain why gasoline is more prone to explosive vapor-air mixtures at normal temperatures, whereas kerosine generally requires heating or special conditions to pose a similar hazard.

When kerosine can still behave “explosively”

Despite being less volatile, kerosine becomes hazardous in certain scenarios that enable flammable vapor or mist to accumulate and ignite rapidly.

• Heating and confined spaces: Warmed kerosine in tanks, sheds, or rooms with poor ventilation can build up vapor; a spark or hot surface can trigger a violent ignition.
• Atomization/sprays: Fine mists (from leaks, pressurized sprayers, burners, or impact) burn much faster than pool fires and can flash back explosively.
• Hot surfaces: Because kerosine’s autoignition temperature can be near ~210°C, contact with sufficiently hot engine parts or heaters can cause ignition without a spark if vapor is present.
• Boiler and burner operations: Improper start-up or shutdown, or fuel accumulation, can lead to delayed ignition events that feel explosive.
• Large tanks on hot days: Jet fuel (a kerosine cut) in aircraft or storage tanks can form flammable headspace vapors; industry uses inerting and controls to reduce risk.

These conditions don’t change kerosine’s lower volatility, but they create the vapor or mist—and confinement—needed for a sudden, forceful ignition.

Practical safety takeaways

The following practices reduce the risk of flammable vapor accumulation and ignition with both fuels, especially in garages, workshops, and storage areas.

• Ventilation: Store and dispense fuels in well-ventilated areas. Gasoline vapors can pool near floors; avoid basements or pits.
• Ignition control: Keep fuels away from open flames, sparks, hot work, space heaters, and hot engine components.
• Temperature awareness: Treat warmed kerosine with extra caution; avoid heating containers and never use improvised heaters.
• Containers and storage: Use approved, tightly sealed containers; label clearly; keep out of living areas; follow local fire codes.
• Transfer and cleanup: Prevent sprays and mists; clean spills immediately; dispose of soaked rags safely to avoid spontaneous heating or vapor release.
• Equipment operation: Follow manufacturer procedures for burners, generators, and heaters; allow purging/venting before re-ignition.

Good handling and storage practices address the main factors—vapor formation and ignition sources—that drive explosion risk for both fuels.

Bottom line

Gasoline is generally more explosive than kerosine in everyday settings because it produces ignitable vapors at far lower temperatures and in far greater amounts. Kerosine is less volatile and often burns as a pool fire, yet it can still ignite violently when heated, confined, or atomized. Treat both with respect: control vapors, control ignition sources, and ensure ventilation.

Summary

Gasoline’s high volatility and very low flash point make it the greater explosion hazard at ambient temperatures. Kerosine’s higher flash point means it is usually less prone to explosive vapor-air mixtures, but it can become dangerous when warmed, confined, or sprayed as a mist. Proper storage, ventilation, and ignition control are essential for both fuels.

Is kerosene more explosive than gasoline?

Kerosene has a flash point of 110 degrees Fahrenheit. Gasoline has a flash point of -40 degrees. This means that at 110 degrees or higher kerosene gives off flammable vapors and can ignite. However, gasoline requires a temperature of only 40 degrees to vaporize to cause an explosion or fire.

What fuel is the most flammable?

Of all the dangerous chemical gases, chlorine trifluoride is known to be the most flammable. It is a colorless and extremely reactive gas that can burn through concrete and gravel.

What is the flash point of kerosene vs gasoline?

Gasoline has a much lower flash point than kerosene, typically around -40°F (-40°C), while kerosene’s flash point is around 100°F (38°C) or higher. This difference in flash point means gasoline produces flammable vapors at very cold temperatures, making it highly volatile and dangerous, whereas kerosene is less volatile and safer to handle and store. 
Gasoline

• Flash Point: Approximately -40°F (-40°C). 
• Volatility: Highly volatile, meaning it easily gives off flammable vapors even at very low temperatures. 
• Safety: Its low flash point makes it inherently more dangerous to store and handle. 

Kerosene

• Flash Point: Around 100°F (38°C) or higher. 
• Volatility: Less volatile than gasoline, requiring a higher temperature to produce enough flammable vapor to ignite. 
• Safety: Its higher flash point makes it a relatively safer fuel for storage and handling compared to gasoline. 

Key Takeaway
The lower flash point of gasoline indicates it can ignite much more easily, while the higher flash point of kerosene signifies it is a safer fuel to handle because it needs to be heated to a much higher temperature to generate a flammable vapor.

Is kerosene more powerful than gasoline?

Kerosene has a higher molecular weight and a lower octane rating than gasoline. This means it has a lower energy density and is less efficient than fuel. It is also less refined than gasoline, which means it contains impurities and contaminants that can affect its performance and stability.