Naphtha

Naphtha ( or ) is a flammable liquid hydrocarbon mixture.
Mixtures labelled "naphtha" have been produced from natural gas condensates, petroleum distillates, and the distillation of coal tar and peat.
In different industries and regions "naphtha" may also be crude oil or refined products such as kerosene. Mineral spirits, also historically known as "naphtha", is not the same chemical.
"Nephi" and "naphthar" are sometimes used as a synonyms. It is also known as Shellite in Australia.
Etymology.
The word "naphtha" is from Latin and Ancient Greek (νάφθα), derived from Middle Persian "naft" ("wet", "naphtha"), the latter meaning of which was an assimilation from the Akkadian "napṭu" (see Semitic relatives such as Arabic "nafṭ" ["petroleum"], Syriac ܢܰܦܬܳܐ "naftā") and Hebrew נֵפְט "neft" (meaning petroleum). In Ancient Greek, it was used to refer to any sort of petroleum or pitch.
In the Song of the Three Children the Greek word νάφθα designates one of the materials used to stoke the fiery furnace. The translation of Charles Brenton renders this as "rosin".
The book of II Maccabees 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 [literally hoi polloi]."
It enters the word napalm, a contraction of the "na" of "naphthenic acid" and "palm" of "palmitic acid", originally made from a mixture of naphthenic acid combined with aluminium and magnesium salts of palmitic acid. Naphtha is the root of the word naphthalene, and can also be recognised in the word phthalate, and the paint colour phthalo blue.
In older usage, "naphtha" simply meant crude oil, but this usage is now obsolete in English. It was also used for mineral spirits (also known as "Stoddard Solvent"), originally the main active ingredient in Fels Naptha laundry soap. The Ukrainian and Belarusian word ("nafta"), Lithuanian, Latvian and Estonian "nafta" and the Persian "naft" () mean "crude oil". The Russian word нефть ("neft'") means "crude oil", but нафта ("nafta") is a synonym of ligroin. Also, in Albania, Bosnia and Herzegovina, Bulgaria, Croatia, Finland, Italy, Serbia, Slovenia, 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 and it generally indicates diesel fuel. In 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 Argentina, Paraguay and Uruguay to refer to gasoline/petrol. In Poland, the word ' means kerosene, and colloquially crude oil (technical name for crude oil is ', also colloquially used for diesel fuel as ""). In Flemish, the word "naft" is used colloquially for gasoline.
There is a hypothesis that the word is connected with the name of the Indo-Iranian god Apam Napat, which occurs in Vedic and in Avestic; the name means "grandson of (the) waters", and the Vedas describe him as emerging from water golden and shining "with bright rays", perhaps inspired by a burning seepage of natural gas.
Types.
Various qualifiers have been added to the term "naphtha" by different sources in an effort to make it more specific:
One source distinguishes by boiling point:
Another source differentiates "light" and "heavy" comments on the hydrocarbon structure, but offers a less precise dividing line:
Both of these are useful definitions, but they are incompatible with one another and the latter does not provide for mixes containing both six and seven carbon atoms per molecule. These terms are also sufficiently broad that they are not widely useful.
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 tankers. Other common dilutants include natural-gas condensate, and light crude. However, naphtha is a particularly efficient dilutant and can be recycled from diluted heavy crude after transport and processing. The importance of oil dilutants has increased as global production of lighter crude oils has fallen and shifted to exploitation of heavier reserves.
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 making it easy to ignite. Naphtha is sometimes preferred over kerosene due to a lower incidence of fuel line clogging.
Plastics.
Naphtha is a crucial component in the production of plastics.
Health and safety considerations.
The safety data sheets (SDSs) from various naphtha vendors are also indicative of the non-specific nature of the product and reflect the considerations due for a flammable mixture of hydrocarbons: flammability, carcinogenicity, skin and airway irritation, etc.
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 ppm (400 mg/m3) over an 8-hour workday. The US National Institute for Occupational Safety and Health (NIOSH) has set a recommended exposure limit (REL) of 100 ppm (400 mg/m3) over an 8-hour workday. At levels of 1000 ppm, which equates to 10% of the lower explosive limit, naphtha is immediately dangerous to life and health.