View source for Naphtha

{{Short description|Flammable liquid hydrocarbon mixture}}
{{Distinguish|Naphthalene}}
{{For-multi|the hydrocarbon liquid stream derived from the refining of crude oil|Petroleum naphtha|the character in the book by Thomas Mann|Herr Naphta}}
{{More citations needed|date=October 2015}}

'''Naphtha''' ({{IPAc-en|ˈ|n|æ|f|θ|ə}}, recorded as less common or nonstandard<ref>{{cite web | url=https://www.merriam-webster.com/dictionary/naphtha | title=Definition of NAPHTHA | date=18 December 2024 }}</ref> in all dictionaries: {{IPAc-en|ˈ|n|æ|p|θ|ə}}) is a flammable liquid hydrocarbon mixture. Generally, it is a fraction of [[crude oil]], but it can also be produced from [[natural-gas condensate]]s, [[petroleum distillate]]s, and the [[fractional distillation]] of [[coal tar]] and [[peat]].  In some industries and regions, the name ''naphtha'' refers to [[crude oil]] or refined petroleum products such as [[kerosene]] or [[diesel fuel]].

Naphtha is also known as Shellite in Australia.<ref name="shellite" />

==Etymology==
[[File:Camp fuel.jpg|thumb|upright|White gas, exemplified by [[Coleman fuel|Coleman Camp Fuel]], is a common naphtha-based fuel used in many lanterns and stoves.]]

The word ''naphtha'' comes from [[Latin]] through [[Ancient Greek]] ({{Lang|grc|νάφθα}}), derived from [[Middle Persian]] ''naft'' ("wet", "naphtha"),<ref>{{cite web|url=http://agiw.fak1.tu-berlin.de/Auditorium/FAByzIsl/SO8/PersErb.htm |archive-url=https://web.archive.org/web/20110811054725/http://agiw.fak1.tu-berlin.de/Auditorium/FAByzIsl/SO8/PersErb.htm |archive-date=2011-08-11 |title= Persisches Erbe im Griechischen, Lateinischen, Arabischen, Türkischen und in verschiedenen heutigen europäischen Sprachen (''Persian Heritage in Greek, Latin, Arabic, Turkic and Various Modern European Languages'')| author=Christian Gizewski ([[Technische Universität Berlin]])|publisher=Technische Universität Berlin| access-date = 2010-02-28}}</ref><ref name="D. N. MacKenzie1971">{{cite book|author=David Neil MacKenzie|title=A Concise Pahlavi Dictionary|year=1971|publisher=Oxford University Press|isbn=978-1-934768-59-4|page=57}}</ref> the latter meaning of which was an assimilation from the [[Akkadian language|Akkadian]] [[wikt:napṭum|𒉌𒆳𒊏]] {{Transliteration|akk|napṭu}} (see [[Semitic languages|Semitic]] relatives such as [[Arabic language|Arabic]] {{lang|ar|نَفْط}} {{Transliteration|ar|nafṭ}} ["petroleum"], [[Syriac language|Syriac]] {{Lang|syc|ܢܰܦܬܳܐ}} ''naftā'', and [[Hebrew]] {{Lang|he|נֵפְט}} {{Transliteration|he|neft}}, meaning petroleum).<ref>{{cite web |title=ENGLISH i. Persian Elements in English |url=http://www.iranicaonline.org/articles/english |website=www.iranicaonline.org |publisher=[[Encyclopaedia Iranica]] |access-date=1 September 2018 |language=en}}</ref>

=== Antiquity ===
The book of [[II Maccabees]] (2nd cent. BC) tells how a "thick water" was put on a sacrifice at the time of [[Nehemiah]] and when the sun shone it caught fire. It adds that "those around Nehemiah termed this 'Nephthar,' which means Purification, but it is called Nephthaei by the many."<ref>{{bibleverse|2|Maccabees|1:36}}</ref> This same substance is mentioned in the [[Mishnah]] as one of the generally permitted oils for lamps on [[Shabbat]], although [[Rabbi Tarfon]] permits only [[olive oil]] (Mishnah Shabbat 2). 

In Ancient Greek, it was used to refer to any sort of [[petroleum]] or [[Pitch (resin)|pitch]]. The Greek word {{lang|el|νάφθα}} designates one of the materials used to stoke the fiery furnace in the [[Song of the Three Children]] (possibly 1st or 2nd cent. BC).  The translation of Charles Brenton renders this as "[[rosin]]."

The naphtha of antiquity is explained to be a "highly flammable light [[Fractionation|fraction]] of petroleum, an extremely volatile, strong-smelling, gaseous liquid, common in oil deposits of the Near East;" it was a chief ingredient in incendiary devices<!-- such as the ''pyr atutomaton''--> described by Latin authors of the Roman period.<ref name=mayor>{{cite book|last=Mayor |first=Adrienne |author-link=Adrienne Mayor |title=Greek Fire, Poison Arrows, and Scorpion Bombs: Biological and Chemical Warfare in the Ancient World |location=Woodstock, NY |publisher=Overlook Duckworth |date=2009 |url=https://books.google.com/books?id=QysqAQAAIAAJ&q=naphtha |page=227 |isbn=0715638521<!--, 9780715638521-->}} [https://books.google.com/books?id=M_v57ETfcvQC&lpg=PP1 digital copy]</ref>

=== Modern period ===
<!--Since the 19th century-->Since the 19th century, [[solvent naphtha]] has denoted a product ([[xylene]] or [[trimethylbenzenes]]) derived by [[fractional distillation]] from petroleum;<ref name=remsen>{{cite book|last=Daunicht |first=Hubert K. |author-link=<!--Hubert K. Daunicht--> |title=Greek Fire, Poison Arrows, and Scorpion Bombs: Biological and Chemical Warfare in the Ancient World |location=Woodstock, NY |publisher=Overlook Duckworth |date=2009 |url=https://books.google.com/books?id=84FfBiU_gi4C&pg=PA307 |page=307 |isbn=<!--0715638521, -->9780715638521}}</ref> these [[mineral spirits]], also known as "Stoddard Solvent," were originally the main active ingredient in [[Fels Naptha]] laundry soap.<ref>{{cite web|url=http://digitalhistory.hsp.org/pafrm/org/fels-company|title=Fels & Company |website=Hsp.org|accessdate=2016-09-28}}</ref> The naphtha in Fels Naptha was later removed as a cancer risk.<ref>{{Cite web |title=Portugrocer: 1942 |url=https://www.shorpy.com/node/27017 |access-date=2023-05-03 |website=Shorpy.com |language=en}}</ref>

The usage of the term "naphtha" during this time typically implies petroleum naphtha, a colorless liquid with a similar odor to gasoline. However, "coal tar naphtha," a reddish brown liquid that is a mixture of hydrocarbons ([[toluene]], xylene, and [[cumene]], etc.), could also be intended in some contexts.<ref name=sittig>{{cite book|last=Sittig |first=Marshall |author-link=<!--Marshall Sittig--> |editor1-last=Greene |editor1-first=Stanley A. |editor1-link=<!--Stanley A. Greene--> |editor2-last=Pohanish|editor2-first=Richard P. |editor2-link=<!--Richard P. Pohanish-->|chapter=Naphtha |title=Sittig's Handbook of Pesticides and Agricultural Chemicals |location= |publisher=William Andrew |date=2013 |chapter-url=https://books.google.com/books?id=hAoKEHpyu6wC&pg=PA636 |page=636 |isbn=<!--0815519036, -->9780815519034}}</ref>

=== Petroleum ===
In older usage,{{when|date=January 2022}} "naphtha" simply meant [[crude oil]], but this usage is now obsolete in English. There are a number of [[cognate]]s to the word in different modern languages, typically signifying "petroleum" or "crude oil."

The [[Ukrainian language|Ukrainian]] & [[Belarusian language|Belarusian]] word [[:uk:нафта|нафта]] (''nafta''), [[Lithuanian language|Lithuanian]], [[Latvian language|Latvian]], & [[Estonian language|Estonian]] "nafta," and the [[Persian language|Persian]] {{Transliteration|fa|naft}} ({{lang|fa|نفت}}) mean "crude oil." The Russian word {{lang|ru|нефть}} (''neft<nowiki>'</nowiki>'') means "crude oil," but нафта (''nafta'') is a synonym of [[ligroin]]. Also, in [[Albania]], [[Bosnia and Herzegovina]], [[Bulgaria]], [[Croatia]], [[Finland]], [[Italy]], [[Serbia]], [[Slovenia]], and [[North Macedonia|Macedonia]] ''nafta'' (нафта in Cyrillic) is colloquially used to indicate [[diesel fuel]] and [[crude oil]]. In the [[Czech Republic]] and [[Slovakia]], ''nafta'' was historically used for both diesel fuel and crude oil, but its use for crude oil is now obsolete<ref>{{cite web|url=http://slovnik.juls.savba.sk/?w=nafta&s=exact&c=k045&d=kssj4&d=psp&d=scs&d=sss&d=peciar&d=hssjV&d=ma&d=obce&d=priezviska&d=un&ie=utf-8&oe=utf-8 |title=Slovenské slovníky |publisher=Slovnik.juls.savba.sk |access-date=2015-10-26}}</ref> and it generally indicates diesel fuel. In [[Bulgarian language|Bulgarian]], ''nafta'' means diesel fuel, while ''neft'', as well as ''petrol'' (петрол in Cyrillic), means crude oil. ''Nafta'' is also used in everyday parlance in [[Rioplatense Spanish|Argentina, Uruguay]] and Paraguay to refer to gasoline/petrol.<ref name="Mairal2012">{{cite book|author=Pedro Mairal|title=El año del desierto|url=https://books.google.com/books?id=dQ56G7us0-4C&pg=PA71|year=2012|publisher=Stockcero, Inc|isbn=978-1-934768-59-4|pages=71–}}</ref> Similarly, in [[Flemish dialects|Flemish]], the word ''naft(e)'' is used colloquially for gasoline.<ref name="Clyne1992">{{cite book|author=Michael G. Clyne|title=Pluricentric Languages: Differing Norms in Different Nations|url=https://books.google.com/books?id=wawGFWNuHiwC&pg=PA85|year=1992|publisher=Walter de Gruyter|isbn=978-3-11-012855-0|pages=85–}}</ref> In Poland, the word ''{{wikt-lang|pl|nafta|}}'' means [[kerosene]],<ref name="Taranov2013">{{cite book|author=Andrey Taranov|title=Polish vocabulary for English speakers - 7000 words|url=https://books.google.com/books?id=kR-kAQAAQBAJ&pg=PA98|date=23 October 2013|publisher=BoD - Books on Demand|isbn=978-1-78071-417-2|pages=98–}}</ref> and colloquially crude oil (the technical name for crude oil is ''{{wikt-lang|pl|ropa naftowa|}}'', also colloquially used for diesel fuel as ''{{wikt-lang|pl|ropa|}}'').

==Types==
Naphtha has been divided into two types by many sources in order to differentiate between common grades more clearly:

One source<ref>{{cite conference |first=Rune |last=Prestvic |author2=Kjell Moljord |author3=Knut Grande |author4=Anders Holmen |title=Compositional analysis of naphtha and reformate |book-title=Catalytic naphtha reforming | pages=2 |publisher=CRC Press |year=2004 |location=USA |isbn=9780203913505 |url=https://books.google.com/books?id=Bjs7d2xnm1UC&pg=PA60 |access-date=2010-02-03}}</ref> distinguishes by boiling point as well as carbon atom count per molecule:
{{blockquote|{{ubl
 |''Light naphtha'' is the fraction boiling between {{convert|30|and|90|C|F}} and consists of molecules with 5–6 carbon atoms. 
 |''Heavy naphtha'' boils between {{convert|90|and|200|C|F}} and consists of molecules with 6–12 carbon atoms.
 }} 
}}

''Chemistry of Hazardous Materials'' differentiates light and heavy based on the carbon atom count and hydrocarbon structure:<ref>{{cite book |last1=Meyer |first1=Eugene |title=Chemistry of hazardous materials |date=1998 |publisher=Brady : Prentice-Hall |location=Upper Saddle River, N.J |isbn=0-8359-5175-8 |page=458 |edition=3rd}}</ref>
{{blockquote|{{ubl
 |''Light'' [is] a mixture consisting mainly of straight-chained and cyclic aliphatic hydrocarbons having from five to six carbon atoms per molecule.  |''Heavy'' [is] a mixture consisting mainly of straight-chained and cyclic aliphatic hydrocarbons having from seven to nine carbon atoms per molecule.
 }} 
}}

Some sources also define ''petroleum naphtha'', which contains both heavy and light naphtha, and typically consists of 15-30% of crude oil by weight.<ref name = "naphtha engines"/>

== Uses ==

=== Heavy crude oil dilution ===
Naphtha is used to dilute [[heavy crude oil]] to reduce its viscosity and enable/facilitate transport; undiluted heavy crude cannot normally be transported by pipeline, and may also be difficult to pump onto [[oil tanker]]s. Other common dilutants include [[natural-gas condensate]] and [[Light crude oil|light crude]]. However, naphtha is a particularly efficient dilutant and can be recycled from diluted heavy crude after transport and processing.<ref>{{Cite book|last1=Glenat|first1=Philippe|last2=Heraud|first2=Jean-Philippe|last3=Gateau|first3=Patrick|last4=Henaut|first4=Isabelle|last5=Argillier|first5=J.-Francois|date=2005-01-01|title=Heavy Oil Dilution|url=https://www.onepetro.org/conference-paper/SPE-97763-MS|language=en|publisher=Society of Petroleum Engineers|doi=10.2118/97763-MS|isbn=9781613990056|s2cid=73605226 }}</ref><ref name=":0">{{Cite web|url=https://www.researchgate.net/publication/286937181|title=Dilution of heavy crude oils for pipeline transportation purposes: The asphaltene instability issue}}</ref><ref name=":1">{{Cite web|url=https://www.worldoil.com/news/2019/1/29/diluting-venezuela-s-heavy-crude-just-got-harder|title=Diluting Venezuela's heavy crude just got harder|website=www.worldoil.com|date=29 January 2019 |access-date=2019-04-09}}</ref> The importance of oil dilutants has increased as global production of lighter crude oils has fallen and shifted to exploitation of heavier reserves.<ref name=":0" />

=== Fuel ===
Light naphtha is used as a fuel in some commercial applications. One notable example is wick-based cigarette lighters, such as the [[Zippo]], which draw "lighter fluid"—naphtha—into a wick from a reservoir to be ignited using the flint and wheel.

It is also a fuel for camping stoves and oil lanterns, known as "white gas", where naphtha's low boiling point makes it easy to ignite. Naphtha is sometimes preferred over kerosene because it clogs fuel lines less. The outdoor equipment manufacturer [[Mountain Safety Research|MSR]] published a list of trade{{nbsp}}names and translations to help outdoor enthusiasts obtain the correct products in various countries.<ref>{{cite web | url=https://support.cascadedesigns.com/hc/en-us/articles/35376970536979-Where-do-I-get-fuel-in-foreign-countries-and-what-other-types-of-fuel-can-I-use-with-my-stove | title=Where do I get fuel in foreign countries and what other types of fuel can I use with my stove? | date=7 July 2025 }}</ref>

Naphtha was also historically used as both a fuel and a [[Working fluid|working fluid]] in some [[Naphtha launch|small  boats]] where steam technology was impractical; most were built to circumvent safety laws relating to traditional steam launches.<ref name="Durant, 1976">{{cite book |last=Durant |first=Kenneth |title=The Naptha Launch |year=1976}}</ref>

As an internal combustion engine fuel, petroleum naphtha has seen very little use and suffers from lower efficiency and low [[octane rating]]s, typically 40 to 70 [[Octane_rating#RON|RON]]. It can be used to run unmodified diesel engines, though it has a longer ignition-delay than diesel. Naphtha tends to be noisy in combustion due to the high pressure rise rate. There is a possibility of using naphtha as a low-octane base fuel in an octane-on-demand concept, with the engine drawing a high-octane mix only when needed. Naptha benefits from lesser emissions in refinement: fuel energy losses from "well-to-tank" are 13%; lower than the 22% losses for petroleum.<ref name = "naphtha engines">{{cite journal |last1=Park |first1=Wonah |title=Naphtha as a Fuel for Internal Combustion Engines |journal=International Journal of Automotive Technology |date=August 2021 |volume=22 |issue=4 |pages=1119–1133 |doi=10.1007/s12239-021-0100-9}}</ref>

=== Plastics ===
Naphtha is a crucial component in the production of [[plastics]].<ref>{{cite web|title=How Plastics are Made|url=https://plasticseurope.org/plastics-explained/how-plastics-are-made/|website=Plastics Europe|publisher=Association of Plastics Manufacturers|location=Brussels}}</ref>

==Health and safety considerations==
The [[safety data sheet]]s (SDSs) from various naphtha vendors indicate various hazards such as a flammable mixture of [[hydrocarbon]]s: [[flammability]], [[carcinogenicity]], skin and [[airway]] irritation, etc.<ref>
{{cite web
 |url=http://hazard.com/msds/mf/baker/baker/files/p1696.htm
 |title=Petroleum Ether
 |publisher=Hazard.com
 |date=1998-04-21
 |access-date=2015-10-26
}}</ref><ref name="shellite">
{{cite web
 |url=https://www.recochem.com/wp-content/uploads/2023/07/Shellite-NZ-v6.pdf
 |title=Material Safety Data Sheet : Shellite
 |publisher=Recochem.com
 |access-date=2015-10-26
}}</ref><ref>
{{cite web
 |url=http://www.cooperbooth.com/datasheets/160606.pdf
 |title=Material Safety Data Sheet : Ronsonol Lighter Fuel
 |publisher=Cooperbooth.com
 |access-date=2015-10-26
}}</ref><ref>{{cite web
 |url=http://www.nafaa.org/msds.html
 |title=NAFAA
 |publisher=NAFAA
 |access-date=2015-10-26
 |archive-url=https://web.archive.org/web/20160304091246/http://www.nafaa.org/msds.html
 |archive-date=2016-03-04
 |url-status=usurped
 }}</ref>

Humans can be exposed to naphtha in the workplace by inhalation, ingestion, dermal contact, and eye contact. The [[US]] [[Occupational Safety and Health Administration]] (OSHA) has set the [[permissible exposure limit]] for naphtha in the workplace as 100&nbsp;[[Parts-per notation|ppm]] (400&nbsp;mg/m<sup>3</sup>) over an 8-hour workday. The [[US]] [[National Institute for Occupational Safety and Health]] (NIOSH) has set a [[recommended exposure limit]] (REL) of 100&nbsp;ppm (400&nbsp;mg/m<sup>3</sup>) over an 8-hour workday. At levels of 1000&nbsp;ppm, which equates to 10 times the lower exposure limit, naphtha is [[IDLH|immediately dangerous to life and health]].<ref>
{{Cite web
 |title = CDC - NIOSH Pocket Guide to Chemical Hazards - Naphtha (coal tar)
 |url = https://www.cdc.gov/niosh/npg/npgd0438.html
 |website = www.cdc.gov
 |access-date = 2015-11-27}}</ref>

==See also==
* [[Coleman fuel]]
* [[Fels-Naptha]]
* [[Fractional distillation]]
* [[Fluid catalytic cracking]]
* [[Greek fire]]
* [[Hydrocarbon]]
* [[Kerosene]]
* [[Mineral spirits]]
* [[Naphtha launch]]
* [[Oil refinery]]
* [[Petroleum distillation]]
* [[Petroleum naphtha]]
* [[Tar]]

==References==
{{Reflist|30em}}

== External links ==
* {{Wiktionary inline}}
* {{Commons category inline}}

{{Authority control}}

[[Category:Commodity chemicals]]
[[Category:Hydrocarbon solvents]]
[[Category:Petroleum products]]