White spirit
Encyclopedia
White spirit [CAS 64475-85-0], also known as Stoddard solvent [CAS 8052-41-3] or mineral spirits, is a paraffin
Paraffin
In chemistry, paraffin is a term that can be used synonymously with "alkane", indicating hydrocarbons with the general formula CnH2n+2. Paraffin wax refers to a mixture of alkanes that falls within the 20 ≤ n ≤ 40 range; they are found in the solid state at room temperature and begin to enter the...

-derived clear, transparent liquid which is a common organic solvent
Solvent
A solvent is a liquid, solid, or gas that dissolves another solid, liquid, or gaseous solute, resulting in a solution that is soluble in a certain volume of solvent at a specified temperature...

 used in painting and decorating. In 1924, an Atlanta dry cleaner
Dry cleaning
Dry cleaning is any cleaning process for clothing and textiles using a chemical solvent other than water. The solvent used is typically tetrachloroethylene , abbreviated "perc" in the industry and "dry-cleaning fluid" by the public...

 named W. J. Stoddard worked with Lloyd E. Jackson of the Mellon Research Institute to develop specifications for a less volatile dry cleaning solvent as an alternative to more volatile petroleum solvents. Dry cleaners began using it in 1928 and it was the predominant dry cleaning solvent in the United States from the late 1920s until the late 1950s.

It is a mixture of aliphatic and alicyclic C7 to C12 hydrocarbon
Hydrocarbon
In organic chemistry, a hydrocarbon is an organic compound consisting entirely of hydrogen and carbon. Hydrocarbons from which one hydrogen atom has been removed are functional groups, called hydrocarbyls....

s with a maximum content of 25% of C7 to C12 aromatic hydrocarbon
Aromatic hydrocarbon
An aromatic hydrocarbon or arene is a hydrocarbon with alternating double and single bonds between carbon atoms. The term 'aromatic' was assigned before the physical mechanism determining aromaticity was discovered, and was derived from the fact that many of the compounds have a sweet scent...

s. A typical composition for mineral spirits is the following: > 65% C10 or higher hydrocarbons, aliphatic solvent hexane
Hexane
Hexane is a hydrocarbon with the chemical formula C6H14; that is, an alkane with six carbon atoms.The term may refer to any of four other structural isomers with that formula, or to a mixture of them. In the IUPAC nomenclature, however, hexane is the unbranched isomer ; the other four structures...

, and a maximum aromatic hydrocarbon
Aromatic hydrocarbon
An aromatic hydrocarbon or arene is a hydrocarbon with alternating double and single bonds between carbon atoms. The term 'aromatic' was assigned before the physical mechanism determining aromaticity was discovered, and was derived from the fact that many of the compounds have a sweet scent...

 content of 0.1% by volume, a kauri-butanol
Kauri-butanol
The Kauri-butanol value is an international, standardized measure of solvent power for a hydrocarbon solvent, and is governed by an ASTM standardized test, ASTM D1133. The result of this test is a scaleless index, usually referred to as the "Kb value". A higher Kb value means the solvent is more...

 value of 29, an initial boiling point of 149 °F (65 °C), a dry point of approximately 156 °F (69 °C), and a specific mass of 0.7 g/cc.

Stoddard solvent is a specific mixture of hydrocarbons typically > 65% C10 or higher hydrocarbons .

White spirit is used as an extraction solvent, as a cleaning solvent, as a degreasing solvent and as a solvent in aerosols
Aerosol spray
Aerosol spray is a type of dispensing system which creates an aerosol mist of liquid particles. This is used with a can or bottle that contains a liquid under pressure. When the container's valve is opened, the liquid is forced out of a small hole and emerges as an aerosol or mist...

, paint
Paint
Paint is any liquid, liquefiable, or mastic composition which after application to a substrate in a thin layer is converted to an opaque solid film. One may also consider the digital mimicry thereof...

s, wood preservatives
Wood preservation
All measures that are taken to ensure a long life of wood fall under the definition wood preservation . Apart from structural wood preservation measures, there are a number of different preservatives and processes that can extend the life of wood, timber, wood structures or engineered wood...

, lacquer
Lacquer
In a general sense, lacquer is a somewhat imprecise term for a clear or coloured varnish that dries by solvent evaporation and often a curing process as well that produces a hard, durable finish, in any sheen level from ultra matte to high gloss and that can be further polished as required...

s, varnish
Varnish
Varnish is a transparent, hard, protective finish or film primarily used in wood finishing but also for other materials. Varnish is traditionally a combination of a drying oil, a resin, and a thinner or solvent. Varnish finishes are usually glossy but may be designed to produce satin or semi-gloss...

es, and asphalt
Asphalt
Asphalt or , also known as bitumen, is a sticky, black and highly viscous liquid or semi-solid that is present in most crude petroleums and in some natural deposits, it is a substance classed as a pitch...

 products. In western Europe about 60% of the total white spirit consumption is used in paints, lacquers and varnishes. White spirit is the most widely used solvent in the paint industry. In households, white spirit is commonly used to clean paint brushes after decorating. Its paint thinning properties enable brushes to be cleaned (by preventing the paint from hardening and ruining the bristles), enabling them to be reused.

Three different types and three different grades of white spirit exist. The type refers to whether the solvent has been subjected to hydrodesulfurization
Hydrodesulfurization
Hydrodesulfurization is a catalytic chemical process widely used to remove sulfur from natural gas and from refined petroleum products such as gasoline or petrol, jet fuel, kerosene, diesel fuel, and fuel oils...

 (removal of sulfur) alone (type 1), solvent extraction (type 2) or hydrogenation
Hydrogenation
Hydrogenation, to treat with hydrogen, also a form of chemical reduction, is a chemical reaction between molecular hydrogen and another compound or element, usually in the presence of a catalyst. The process is commonly employed to reduce or saturate organic compounds. Hydrogenation typically...

 (type 3). Each type comprises three different grades: low flash grade, regular grade, and high flash grade. The grade is determined by the crude oil used as the starting material and the conditions of distillation.

In addition there is type 0, which is defined as distillation fraction with no further treatment, consisting predominantly of saturated C9 to C12 hydrocarbons with a boiling range of 140–200 °C.

Applications

White Spirit is a petroleum distillate commonly used as a paint thinner and mild solvent
Solvent
A solvent is a liquid, solid, or gas that dissolves another solid, liquid, or gaseous solute, resulting in a solution that is soluble in a certain volume of solvent at a specified temperature...

. In industry, mineral spirits is used for cleaning and degreasing
Degreasing
Degreasing often called Defatting, is a term used to describe the removal of fatty acids from an object. In culinary science, the word degreasing refers to various methods which are used to reduce the fat content of a meal. This term can be used to categorize procedures that reduce the fat content...

 machine tools and parts. According to Wesco, a supplier of solvents and cleaning equipment, mineral spirits "are especially effective in removing oils, greases, carbon, and other material from metal." Mineral spirits may also be used in conjunction with cutting oil as a thread cutting and reaming lubricant
Lubricant
A lubricant is a substance introduced to reduce friction between moving surfaces. It may also have the function of transporting foreign particles and of distributing heat...

.

Artists use mineral spirits as an alternative to turpentine
Turpentine
Turpentine is a fluid obtained by the distillation of resin obtained from trees, mainly pine trees. It is composed of terpenes, mainly the monoterpenes alpha-pinene and beta-pinene...

, one that is both less flammable and less toxic. Because of interactions with pigments, artists require a higher grade of mineral spirits than many industrial users, including the complete absence of residual sulfur. Odorless Mineral Spirits are mineral spirits that have been further refined to remove the more toxic aromatic compounds
Aromaticity
In organic chemistry, Aromaticity is a chemical property in which a conjugated ring of unsaturated bonds, lone pairs, or empty orbitals exhibit a stabilization stronger than would be expected by the stabilization of conjugation alone. The earliest use of the term was in an article by August...

, and are recommended for applications such as oil painting
Oil painting
Oil painting is the process of painting with pigments that are bound with a medium of drying oil—especially in early modern Europe, linseed oil. Often an oil such as linseed was boiled with a resin such as pine resin or even frankincense; these were called 'varnishes' and were prized for their body...

, where humans have close contact with the solvent.

In screen printing (also referred to as silk-screening), mineral spirits are often used to clean and unclog screens after printing with oil-based textile and plastisol
Plastisol
Plastisol is a suspension of PVC particles in a plasticizer; it flows as a liquid and can be poured into a heated mold. When heated to around 177 degrees Celsius, the plastic and plasticizer mutually dissolve each other. On cooling the mold below 60 degrees C, a flexible, permanently plasticized...

 inks. They are also used to thin inks used in making monoprints.

Mineral spirits are often used inside liquid filled compasses and gauges.

Physical properties

The physical properties of the three types of white spirit are:
Property T1: Low flash T2: Regular T3: High flash
Initial boiling point
Boiling point
The boiling point of an element or a substance is the temperature at which the vapor pressure of the liquid equals the environmental pressure surrounding the liquid....

 (IBP) (°C)
130–144 145–174 175–200
Final boiling point (°C) IBP+21, max. 220
Average relative molecular mass
Molecular mass
The molecular mass of a substance is the mass of one molecule of that substance, in unified atomic mass unit u...

 
140 150 160
Relative density
Relative density
Relative density, or specific gravity, is the ratio of the density of a substance to the density of a given reference material. Specific gravity usually means relative density with respect to water...

 (15 °C)
0.765 0.780 0.795
Flash point
Flash point
The flash point of a volatile material is the lowest temperature at which it can vaporize to form an ignitable mixture in air. Measuring a flash point requires an ignition source...

 (°C)
21–30 31–54 > 55
Vapour pressure (kPa, 20 °C) 1.4 0.6 0.1
Volatility
Volatility (chemistry)
In chemistry and physics, volatility is the tendency of a substance to vaporize. Volatility is directly related to a substance's vapor pressure. At a given temperature, a substance with higher vapor pressure vaporizes more readily than a substance with a lower vapor pressure.The term is primarily...

 (n-butyl acetate=1)
0.47 0.15 0.04
Autoignition temperature (°C) 240 240 230
Explosion limits (Flammable Range) (% by volume in air) 0.6–6.5 0.6–6.5 0.6–8
Vapour density
Vapour density
Vapour density is the density of a vapour in relation to that of hydrogen. It may be defined as mass of a certain volume of a substance divided by mass of same volume of hydrogen....

 (air=1)
4.5–5 4.5–5 4.5–5
Refractive index
Refractive index
In optics the refractive index or index of refraction of a substance or medium is a measure of the speed of light in that medium. It is expressed as a ratio of the speed of light in vacuum relative to that in the considered medium....

 (at 20 °C)
1.41–1.44 1.41–-1.44 1.41–1.44
Viscosity
Viscosity
Viscosity is a measure of the resistance of a fluid which is being deformed by either shear or tensile stress. In everyday terms , viscosity is "thickness" or "internal friction". Thus, water is "thin", having a lower viscosity, while honey is "thick", having a higher viscosity...

 (cps, 25 °C)
0.74–1.65 0.74–1.65 0.74–1.65
Solubility (% by weight in water) < 0.1 < 0.1 < 0.1
Kauri-butanol
Kauri-butanol
The Kauri-butanol value is an international, standardized measure of solvent power for a hydrocarbon solvent, and is governed by an ASTM standardized test, ASTM D1133. The result of this test is a scaleless index, usually referred to as the "Kb value". A higher Kb value means the solvent is more...

 value
29–33 29–33 29–33
Aniline point
Aniline point
The aniline point of an oil is defined as the temperature at which equal volumes of aniline and the desired oil are completely miscible.The value gives an indication of the aromatic content of the oil, since aniline is an aromatic compound which is dissolved on heating by the aromatics in the oil....

 (°C)
60–75 60–75 60–75
Reactivity  reaction with strong oxidizing agents
Odor threshold (mg/m3) 0.5–5 4

Toxicity

White spirit is mainly classed as an irritant
Irritation
Irritation or exacerbation, in biology and physiology, is a state of inflammation or painful reaction to allergy or cell-lining damage. A stimulus or agent which induces the state of irritation is an irritant...

.

White spirit has a fairly low acute toxicity by inhalation of the vapour, dermal (touching the skin) and oral routes (ingestion). However, acute exposure can lead to central nervous system depression resulting in lack of coordination and slowed reactions. Exposure to very high concentrations in enclosed spaces can lead to general narcotic
Narcotic
The term narcotic originally referred medically to any psychoactive compound with any sleep-inducing properties. In the United States of America it has since become associated with opioids, commonly morphine and heroin and their derivatives, such as hydrocodone. The term is, today, imprecisely...

 effects (drowsiness, dizziness, nausea etc...) and can eventually lead to unconsciousness. Oral ingestion presents a high aspiration
Pulmonary aspiration
Pulmonary aspiration is the entry of material from the oropharynx or gastrointestinal tract into the larynx and lower respiratory tract...

 hazard. Prolonged or repeated skin exposure over a long period of time can result in severe irritant dermatitis
Dermatitis
-Etymology:Dermatitis derives from Greek derma "skin" + -itis "inflammation" and genetic disorder.-Terminology:There are several different types of dermatitis. The different kinds usually have in common an allergic reaction to specific allergens. The term may describe eczema, which is also called...

, also called contact dermatitis
Contact dermatitis
Contact dermatitis is a term for a skin reaction resulting from exposure to allergens or irritants . Phototoxic dermatitis occurs when the allergen or irritant is activated by sunlight....

. Exposure to large amounts of white spirit in direct contact with the skin (e.g. being soaked with 2 litres) for several hours can cause severe chemical burns.
It is recommended that skin exposure be kept to a minimum by use of gloves, and that hands are washed after coming into contact with it. Occasional exposure to skin is highly unlikely to cause any problems.

Exposure to an average white spirit concentration of 240 mg/m3 (40 ppm) for more than 13 years could lead to chronic central nervous system
Central nervous system
The central nervous system is the part of the nervous system that integrates the information that it receives from, and coordinates the activity of, all parts of the bodies of bilaterian animals—that is, all multicellular animals except sponges and radially symmetric animals such as jellyfish...

 effects. White spirit is implicated in the development of "chronic toxic encephalopathy
Encephalopathy
Encephalopathy means disorder or disease of the brain. In modern usage, encephalopathy does not refer to a single disease, but rather to a syndrome of global brain dysfunction; this syndrome can be caused by many different illnesses.-Terminology:...

" among house painters.

Owing to the volatility and low bioavailability of its constituents, white spirit, although it is moderately toxic to aquatic organisms, is unlikely to present significant hazards to the environment. It should not however, be purposely poured down the sink or freshwater drain. It should be disposed of correctly wherever possible.

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