White spirit

White spirit (UK)^{[note 1]} or mineral spirits (US),^[1][2][3] also known as mineral turpentine, turpentine substitute, petroleum spirits, solvent naphtha (petroleum) or Stoddard solvent,^[4][5] is a petroleum-derived clear, transparent liquid which is a common organic solvent used in painting and decorating. In 1924, Atlanta dry cleaner W. J. Stoddard worked with Lloyd E. Jackson of the Mellon Institute of Industrial Research to develop a less volatile dry cleaning solvent as an alternative to the petroleum solvents in use. Dry cleaners began using the result of their work in 1928 and it soon became the predominant dry cleaning solvent in the United States, until the late 1950s.

It is a mixture of aliphatic and alicyclic C7 to C12 hydrocarbons with a maximum content of 25% of C7 to C12 aromatic hydrocarbons. A typical composition for mineral spirits is > 65% C10 or higher hydrocarbons,^[6] aliphatic solvent hexane, and a maximum benzene content of 0.1% by volume, a kauri-butanol value of 29, an initial boiling point of 65 °C (149 °F), a dry point of approximately 69 °C (156 °F), and a density of 0.79 g/ml.

Stoddard solvent is a specific mixture of hydrocarbons, typically > 65% C10 or higher hydrocarbons.^[7]

White spirit is used as an extraction solvent, as a cleaning solvent, as a degreasing solvent and as a solvent in aerosols, paints, wood preservatives, lacquers, varnishes, and asphalt 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 use.

Three different types and three different grades of white spirit exist. The type refers to whether the solvent has been subjected to hydrodesulfurization (removal of sulfur) alone (type 1), solvent extraction (type 2) or hydrogenation (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

A 2-litre (4 imp pt) container of white spirit, fitted with a child-resistant cap

White Spirit is a petroleum distillate that is used as a paint thinner and mild solvent. In industry, mineral spirits are used for cleaning and degreasing machine tools and parts. Mineral spirits may also be used in conjunction with cutting oil as a thread cutting and reaming lubricant.

Mineral spirits are an inexpensive petroleum-based replacement for the vegetable-based turpentine. It is commonly used as a paint thinner for oil-based paint and cleaning brushes, and as an organic solvent in other applications. Mineral turpentine is chemically very different from turpentine, which mainly consists of pinene, and it has inferior solvent properties.^[8] Artists use mineral spirits as an alternative to turpentine since it is 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.

Mineral spirits have a characteristic unpleasant kerosene-like odor. Chemical manufacturers have developed a low odor version of mineral turpentine which contains less of the highly volatile shorter hydrocarbons.^[9] Odorless mineral spirits are mineral spirits that have been further refined to remove the more toxic aromatic compounds, and are recommended for applications such as oil painting, 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 inks. They are also used to thin inks used in making monoprints.

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

Mineral spirits are also used for re-gripping golf clubs. After the old grip is removed, the mineral spirits are poured into the new grip and shaken. After, the mineral spirits are poured on, the new underlying tape and the new grip is slid on. After an hour of drying out, the new grip and club are ready to use.

Although not normally marketed as a fuel, white spirit can be used as an alternative to kerosene in portable stoves, since it is merely a light grade of kerosene. It cannot be used as an alternative to white gas, which is a much more volatile gasoline-like fuel.

White spirits are also a major ingredient in some popular automotive fuel/oil additives, such as Marvel Mystery Oil, as they are capable of dissolving varnish and sludge buildup.^[10]

Mineral spirits are also commonly used for cutting fluid in ultraprecision lathes (commonly referred to as diamond turning machines).

Turpentine substitute

Products marketed as turpentine substitute are generally not made to a standard and can have a wider range of components than products marketed as white spirit. This is to be compared to white spirit which is made to a standard (in the UK, British Standard BS 245, in Germany, DIN 51632). White spirit is used for general cleaning, brush cleaning and paint thinning. Turpentine substitute can be used for general cleaning but is not recommended for paint thinning as it may adversely affect drying times due to the less volatile components. Turpentine substitute may be used for brush cleaning but may leave an oily residue from its heavier components.

Chemical numbers

Physical properties

Mineral turpentine

The physical properties of the three types of white spirit are:

Toxicity

White spirit is mainly classed as an irritant. It 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 effects (drowsiness, dizziness, nausea etc...) and can eventually lead to unconsciousness. Oral ingestion presents a high aspiration hazard. Prolonged or repeated skin exposure over a long period of time can result in severe irritant dermatitis, also called contact dermatitis. Exposure to white spirit in direct contact with the skin for several hours can cause severe chemical burns.^[11] It is recommended that skin exposure be kept to a minimum by use of gloves, and that hands be washed after contact. Occasional exposure to skin is highly unlikely to cause any problems.^{[citation needed]}

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 effects.^{[citation needed]} White spirit is implicated in the development of "chronic toxic encephalopathy" among house painters.^{[citation needed]}

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.

See also

• WD-40

Footnotes

References

External links

• ICPS safety sheet White Spirit (Stoddard Solvent) — World Health Organisation
• Environmental Health Criteria 187 — World Health Organisation
• Chemicals Used In Drycleaning Operations - Environmental Enlightenment
• CDC - NIOSH Pocket Guide to Chemical Hazards