Kerosene

Kerosene, also known in many regions as paraffin, is a combustible hydrocarbon liquid refined from petroleum. It has been widely used since the nineteenth century as a domestic and industrial fuel, particularly for lighting, heating and cooking, and remains essential in modern aviation as the basis of jet fuel. Its versatility, relatively high energy density and stability make it suitable for a range of applications from household lamps to high-performance aircraft engines. The term originates from the Greek word kēros, meaning wax, a reference to its early characterisation, and was registered as a trademark by the Nova Scotian geologist Abraham Pineo Gesner in 1854 before becoming generic.

Terminology and Uses

Different regions employ varying terminology. The word kerosene is widely used in countries such as the United States, Canada, India, Nigeria, Argentina, Australia and New Zealand. In contrast, paraffin or closely related forms are used in the United Kingdom, South Africa, East Africa, Norway and parts of Chile. In many parts of Asia the term lamp oil occurs, while in certain areas of the southeastern United States it may be known as coal oil. Because paraffin is also a name for other petroleum derivatives—including liquid paraffin (mineral oil) and paraffin wax—clear labelling is necessary to avoid confusion.
Kerosene is a major fuel for jet aircraft, where highly refined grades are classified as jet fuel. In rocketry, a specialised form known as RP-1 powers certain liquid-fuel engines. Domestic and small-scale uses include heating stoves, lanterns, camping equipment and cooking appliances. In parts of Asia kerosene continues to provide fuel for small marine engines and motorcycles. Regulations in some jurisdictions require kerosene containers to be marked or colour-coded to prevent mixing with more volatile fuels; for example, blue containers distinguish kerosene from red-labelled petrol in parts of the United States.
Public health bodies increasingly advise against household kerosene use. The World Health Organization identifies kerosene as a polluting fuel, linking its indoor combustion with elevated risks of respiratory disease, adverse pregnancy outcomes, asthma, tuberculosis and cataracts. Smoke emissions contain harmful particulate matter, making kerosene less suitable for domestic use where cleaner alternatives are available.

Chemical Properties and Fuel Grades

Kerosene is a clear, low-viscosity liquid produced by fractional distillation of crude oil. It typically distils within a defined boiling range, yielding a mixture with a density between 0.78 and 0.81 g/cm³. The fluid is miscible with hydrocarbon solvents but immiscible with water. Chemically, kerosene consists primarily of straight-chain and branched alkanes and cycloalkanes, which generally form at least 70 per cent of its volume. Aromatic hydrocarbons, including alkylbenzenes and alkylnaphthalenes, are usually limited to under 25 per cent. Olefin content rarely exceeds 5 per cent.
Hydrocarbon molecules in kerosene commonly contain between six and twenty carbon atoms, with nine to sixteen carbon atoms most typical. Its energy content is similar to that of diesel fuel, with a lower heating value around 43 MJ/kg. Kerosene is stable at ordinary temperatures, with a flash point generally above that of petrol, making it comparatively safer to handle.
International standards define several quality grades. ASTM International specifies 1-K and 2-K kerosene, distinguished by sulphur content. Grade 1-K contains less than 0.04 per cent sulphur by weight and burns more cleanly, while Grade 2-K may contain up to 0.3 per cent sulphur and produces more deposits, making it more suitable for outdoor or industrial uses. In the United Kingdom, BS 2869 Class C1 refers to a light, clean-burning fuel for lamps and portable heaters, whereas Class C2 is a heavier heating oil intended for domestic boilers.
Jet fuel standards impose strict requirements for flash point, freezing point, combustion quality and additive content. Low freezing points are essential for high-altitude flight: common commercial jet fuels are formulated to remain liquid at temperatures around –40°C. Autoignition temperatures and flash points are likewise controlled to ensure operational safety.

Physical Characteristics: Melting, Freezing and Combustion Points

Kerosene remains liquid at normal ambient temperatures. Its flash point usually falls between approximately 37°C and 65°C, while autoignition temperatures occur at significantly higher levels. Freezing behaviour varies by grade: household 1-K fuels may freeze around –40°C, whereas aviation kerosene must meet stringent low-temperature specifications to avoid crystallisation during flight.

Early Distillation and Global Development

The earliest known descriptions of kerosene distillation come from the ninth-century Persian polymath Rhazes, who documented techniques for producing a clear, combustible oil (white naphtha) in his Book of Secrets. His methods used an alembic apparatus and materials such as clay and ammonium chloride to refine petroleum. Parallel developments in China during the Ming dynasty saw petroleum extracted and purified for use as lamp fuel, continuing a tradition of oil use dating back to around 1500 BC.
Medieval and early modern distillation practices also produced kerosene-like oils from bitumen and oil shale. By the eighteenth century industrial chemists were familiar with coal-derived oils, though their smoky combustion limited use for indoor lighting. In urban areas piped coal gas provided illumination, but rural households relied primarily on whale oil, especially from sperm whales, which produced a clean, bright flame.

Nineteenth-Century Refinement and Industrial Expansion

Commercial kerosene production emerged in the mid-nineteenth century. Abraham Pineo Gesner developed a method in the 1840s to distil a clean-burning oil from coal and later from naturally occurring bitumen such as albertite. His demonstrations and publications popularised the fuel, though documentation suggests that he originally promoted kerosene as an illuminating gas rather than an oil. Patent disputes occurred between Gesner and the Scottish chemist James Young, who had patented related distillation processes earlier.
Gesner moved to New York in 1854, where the North American Gas Light Company commercialised his patents. As petroleum refining advanced, kerosene became easier and cheaper to produce. Oil shale distillation also contributed to early supplies, particularly before large petroleum fields were exploited. By the late nineteenth century, kerosene had supplanted whale oil as the principal lamp fuel in many regions, supporting widespread adoption of household lighting technologies.

Modern Applications and Environmental Considerations

Although electricity eventually replaced kerosene as the principal source of lighting in industrialised regions, kerosene remains important in aviation and in off-grid communities where access to electricity is limited. Jet propulsion relies heavily on kerosene-based fuels due to their optimal balance of volatility, energy density and combustion characteristics. RP-1, a highly refined kerosene variant, continues to be used in numerous rocket designs.
Growing awareness of health and environmental impacts has influenced policy on domestic kerosene use. Alternatives such as liquefied petroleum gas, solar lighting and improved electricity access have become preferred options in many development programmes. Nevertheless, kerosene retains a significant role in global energy systems, both historically and in contemporary transport and specialised industries.