Properties and Health Effects

What are fuel oils?

Fuel oils are petroleum products that are used in many types of engines, lamps, heaters, furnaces, stoves, and as solvents.  Fuel oils come from crude petroleum and are refined to meet specifications for each use.  Fuel oils are mixtures of aliphatic (open chain and cyclic compounds that are similar to open chain compounds) and aromatic (benzene and compounds similar to benzene) petroleum hydrocarbons.  In addition, they may contain small amounts of nitrogen, sulfur, and other elements as additives.  The exact chemical composition (i.e., precise percentage of each constituent) of each of the fuel oils discussed in this profile may vary somewhat, depending on the source and other factors.  Fuel oils are distinguished from each other primarily by their boiling point ranges, chemical additives, and uses.  In this profile, six fuel oils are discussed.  The fuel oils of interest and common synonyms follow:

fuel oil no. 1 (the most widely used fuel oil)

kerosene

straight-run kerosene

kerosine

range oil 

Deobase (the trade name of a clear, white, deodorized kerosene)

coal oil

JP-5 (jet fuel) 

fuel oil no. 1-D

diesel fuel

diesel fuel oil no. 1

fuel oil no. 2

home heating oil 

gas oil

no. 2 burner oil

fuel oil no. 2-D

diesel fuel oil no. 2

diesel fuel no. 2

diesel oil no. 2

no. 2 diesel

fuel oil no. 4

diesel fuel oil no. 4

heavy residual fuel oil

marine diesel fuel

residual fuel oil no. 4

fuel oil UNSP (which is not referred to by any synonyms)

A fuel oil is referred to by the name used in the cited study.  That is, if one study identifies a fuel oil as fuel oil no. 1, and another study identifies the same fuel oil as kerosene, the names ***fuel oil no. 1*** and ***kerosene*** will be used, respectively.  All fuel oils are liquids at room temperature, although they can evaporate.  The rates at which the various fuel oils will evaporate is dependent on the temperature and the composition of the individual fuel oil.  Most fuel oils are yellowish to light brown in color.  They generally have a kerosene-like odor, are flammable, and burn at temperatures between 177