Kerosene is a colorless, thin mineral oil whose density is between 0.75 and 0.85 grams per cubic centimeter. A mixture of hydrocarbons, it is commonly obtained in the fractional distillation of petroleum as the portion boiling off between 150°C and 275°C (302°F–527°F). Kerosene has been recovered from other substances, notably coal (hence another name, coal oil), oil shale, and wood. Kerosene is also used in space heaters, cook stoves, and water heaters and is suitable for use as a light source when burned in wick-fed  devices.

In the residential sector, kerosene can be used to blend with No. 2 Fuel Oil for very cold weather. Under less severe conditions, a “pour point depressant” can be added to heating oil. Pour point depressants reduce the temperature at which heating oil or diesel begins to congeal and are viable for most weather conditions. Under extremely cold weather, heating oil “clouds” or will precipitate out waxes which will clog filters and orifices. There are no cloud point depressants, which leaves kerosene as the only viable blending component for extremely cold conditions.

Diesel powered trucks and equipment have an additional complication. They are not in fixed locations and are therefore subject to more variable temperatures.

In the commercial sector, kerosene’s primary usage in Delaware is as a blending component added to Diesel fuel to keep it flowing at winter temperatures. Typical Diesel fuel in the Winter may contain 35 to 50% kerosene, with blends upwards to 70% sometimes needed to compensate for the colder weather. Diesel fuel is used in the trucking and construction industries for mobile equipment. Diesel fuel is also used in some stationary plant installations for diesel generator-sets or other prime movers.