Kerosene

Kerosene, or paraffin, is a combustible hydrocarbon liquid which is derived from petroleum. It is widely used as a fuel in aviation as well as households. Its name derives from the Greek κηρός (kērós) meaning "wax"; it was registered as a trademark by Nova Scotia geologist and inventor Abraham Gesner in 1854 before evolving into a generic trademark. It is sometimes spelled kerosine in scientific and industrial usage.

Kerosene is widely used to power jet engines of aircraft (jet fuel), as well as some rocket engines in a highly refined form called RP-1. It is also commonly used as a cooking and lighting fuel, and for fire toys such as poi. In parts of Asia, kerosene is sometimes used as fuel for small outboard motors or even motorcycles. World total kerosene consumption for all purposes is equivalent to about 5,500,000 barrels per day as of July 2023.

The term "kerosene" is common in much of Argentina, Australia, Canada, India, New Zealand, Nigeria, and the United States, while the term paraffin (or a closely related variant) is used in Chile, East Africa, South Africa, Norway, and the United Kingdom. The term "lamp oil", or the equivalent in the local languages, is common in the majority of Asia and the Southeastern United States, although in Appalachia, it is also commonly referred to as "coal oil".

The name "paraffin" is also used to refer to a number of distinct petroleum byproducts other than kerosene. For instance, liquid paraffin (called mineral oil in the US) is a more viscous and highly refined product which is used as a laxative. Paraffin wax is a waxy solid extracted from petroleum.

To prevent confusion between kerosene and the much more flammable and volatile gasoline (petrol), some jurisdictions regulate markings or colourings for containers used to store or dispense kerosene. For example, in the United States, Pennsylvania requires that portable containers used at retail service stations for kerosene be colored blue, as opposed to red (for gasoline) or yellow (for diesel).

The World Health Organization considers kerosene to be a polluting fuel and recommends that "governments and practitioners immediately stop promoting its household use". Kerosene smoke contains high levels of harmful particulate matter, and household use of kerosene is associated with higher risks of cancer, respiratory infections, asthma, tuberculosis, cataracts, and adverse pregnancy outcomes.

Kerosene is a low-viscosity, clear liquid formed from hydrocarbons obtained from the fractional distillation of petroleum between 150 and 275 °C (300 and 525 °F), resulting in a mixture with a density of 0.78–0.81 g/cm³. It is miscible with petroleum solvents, but not with water. It is composed of hydrocarbon molecules that typically contain between 6 and 20 carbon atoms per molecule, predominantly containing 9 to 16 carbon atoms.

Regardless of crude oil source or processing history, kerosene's major components are branched- and straight-chain alkanes (hydrocarbon chains) and naphthenes (cycloalkanes), which normally account for at least 70% of volume. Aromatic hydrocarbons such as alkylbenzenes (single ring) and alkylnaphthalenes (double ring), do not normally exceed 25% by volume of kerosene streams. Olefins are usually not present at more than 5% by volume.