Mineral oil

For crude oil found in geological deposits, see Petroleum.
Bottle of mineral oil as sold in the U.S.

A mineral oil is any of various colorless, odorless, light mixtures of higher alkanes from a non-vegetable (mineral) source, particularly a distillate of petroleum.[1]

The name mineral oil by itself is imprecise, having been used to label many specific oils over the past few centuries. Other names, similarly imprecise, include white oil, liquid paraffin, pariffinum liquidum, and liquid petroleum. Baby oil is a perfumed mineral oil.

Most often, mineral oil is a liquid by-product of the distillation of petroleum to produce gasoline and other petroleum-based products from crude oil. A mineral oil in this sense is a transparent, colorless oil composed mainly of alkanes [2] and cyclic paraffins, related to petroleum jelly (also known as "white petrolatum"). It has a density of around 0.8 g/cm3.[3] Mineral oil is a substance of relatively low value, and it is produced in very large quantities. Mineral oil is available in light and heavy grades, and can often be found in drug stores.

There are three basic classes of refined mineral oils:

Nomenclature

Some of the imprecision in the definition of the names (e.g., "mineral oil", "white oil") reflects usage by buyers and sellers who did not know, and usually did not need to care about, the precise chemical makeup. Prior to the late 19th century, the chemical science to determine such makeup was unavailable in any case, so the fact that one name ended up applied to various oils is unsurprising. A similar lexical situation occurred with the term "white metal".

"Mineral oil", as sold widely and cheaply in the USA, is not sold as such in Britain. Instead British pharmacologists use the terms "Paraffinum perliquidum" for light mineral oil and "Paraffinum liquidum" or "Paraffinum subliquidum" for somewhat thicker (more viscous) varieties. The term "Paraffinum Liquidum" is often seen on the ingredient lists of baby oil and cosmetics. British aromatherapists commonly use the term "white mineral oil".

Toxicology

The World Health Organization classifies untreated or mildly treated mineral oils as Group 1 carcinogens to humans; highly refined oils are classified as Group 3, meaning they are not suspected to be carcinogenic but available information is not sufficient to classify them as harmless.[4]

The UK Food Standards Agency (FSA) carried out a risk assessment on the findings of a survey made in 2011 on risks due to migration of components from printing inks used on carton-board packaging, including mineral oils, into food. The FSA did not identify any specific food safety concerns due to inks.[5]

Applications

Biomedicine

Cell culture

Mineral oil of special purity is often used as an overlay covering microdrops of culture medium in petri dishes, during the culture of oocytes and embryos in IVF and related procedures. The use of oil presents several advantages over the open culture system: it allows for several oocytes and embryos to be cultured simultaneously, but observed separately, in the same dish; it minimizes evaporation (therefore concentration and pH changes) of the medium; it allows for a significant reduction of the medium volume used (as few as 20 microlitres per oocyte instead of several millilitres for the batch culture); and it serves as a temperature buffer minimizing thermal shock to the cells while the dish is taken out of the incubator for observation.

Veterinary uses

Certain mineral oils are used in livestock vaccines, as an adjuvant to stimulate a cell-mediated immune response to the vaccinating agent. In the poultry industry, plain mineral oil can also be swabbed onto the feet of chickens infected with scaly mites on the shank, toes, and webs. Mineral oil suffocates these tiny parasites. In beekeeping, food grade mineral oil saturated paper napkins placed in hives are used as a treatment for tracheal and other mites. It is also used along with a cotton swab to remove un-shed skin on reptiles such as lizards and snakes.

Cosmetics

Mineral oil is a common ingredient in baby lotions, cold creams, ointments and cosmetics. It is a lightweight inexpensive oil that is odorless and tasteless. It can be used on eyelashes to prevent brittleness and breaking and, in cold cream, is also used to remove creme make-up and temporary tattoos. One of the common concerns regarding the use of mineral oil is its presence on several lists of comedogenic substances. These lists of comedogenic substances were developed many years ago and are frequently quoted in the dermatological literature.

A paper written by a cosmetic company and published in the Journal of Cosmetic Dermatology (2005) found that the type of highly refined and purified mineral oil found in cosmetic and skincare products is noncomedogenic (does not clog pores).[6]

Mechanical, electrical and industrial

An electrical heat radiator that uses mineral oil as a heat transfer fluid

Mineral oil is used in a variety of industrial/mechanical capacities as a non-conductive coolant or thermal fluid in electric components as it does not conduct electricity, while simultaneously functioning to displace air and water. Some examples are in transformers where it is known as transformer oil, and in high voltage switchgear where mineral oil is used as an insulator and as a coolant to disperse switching arcs.[7] The dielectric constant of mineral oil ranges from 2.3 at 50 °C to 2.1 at 200 °C.[8]

Electric space heaters sometimes use mineral oil as a heat transfer oil. Because it is noncompressible, mineral oil is used as a hydraulic fluid in hydraulic machinery and vehicles. It is also used as a lubricant and a cutting fluid. Light mineral oil is also used in textile industries and used as a jute batching oil.

An often cited limitation of mineral oil is that it is poorly biodegradable; in some applications, vegetable oils such as cottonseed oil or rapeseed oil may be used instead.[9]

Food preparation

Food grade mineral oil has an E number of E905a, although it is not approved in food products in the European Union, and incidental amounts in foods are carefully regulated.[10] Because of its properties that prevent water absorption, combined with its lack of flavor and odor, food grade mineral oil is a popular preservative for wooden cutting boards, salad bowls and utensils. Rubbing a small amount of mineral oil into a wooden kitchen item periodically will prevent absorption of food odors and ease cleaning, as well as maintain the integrity of the wood, which is otherwise subjected to repeated wetting and drying in the course of use. The oil fills small surface cracks that may otherwise harbor bacteria.[11]

Outside of the European Union, it is occasionally used in the food industry, particularly for candy. In this application, it is typically used for the glossy effect it produces, and to prevent the candy pieces from adhering to each other. It has been discouraged for use in children's foods,[12] though it is still found in many candies, including Swedish Fish.[13] The use of food grade mineral oil is self-limiting because of its laxative effect. The maximum daily intake is calculated to be about 100 mg, of which some 80 mg are contributed from its use on machines in the baking industry.[14]

It is sometimes used as a lubricant in enema preparations, because most of the ingested material is excreted in the stool rather than being absorbed by the body.[14]

Miscellaneous

Mineral oil's ubiquity has led to its use in some niche applications as well:

Applying mineral oil to a butcher block counter top

See also

References

  1. ↑ Mineral oil (Dictionary.com)
  2. ↑ , efsa.europa.eu
  3. ↑ "Mechanical properties of materials". Kaye and Laby Tables of Physical and Chemical Constants. National Physical Laboratory. Retrieved 2008-03-06.
  4. ↑ International Agency for Research on Cancer (17 June 2011). "Agents Classified by the IARC Monographs, Volumes 1–102" (PDF). Lyon, France: International Agency for Research on Cancer. pp. 3, 19. Retrieved 11 November 2011.
  5. ↑ "Survey of printing inks and mineral oils". Food Standards Agency (London). 2011-12-15.
  6. ↑ DiNardo, J. C. (2005). "Is mineral oil comedogenic?". Journal of Cosmetic Dermatology 4: 2–3. doi:10.1111/j.1473-2165.2005.00150.x.
  7. ↑ Suwarno Darma, I.S.; Darma, I. S. (2008). "Dielectric Properties of Mixtures between Mineral Oil and Natural Ester". Proceedings of 2008 International Symposium on Electrical Insulating Materials: 514. doi:10.1109/ISEIM.2008.4664471.
  8. ↑ Shkol'nikov, V. M.; L. A. Bronshtein; Yu. N. Shekhter; O. L. Drozdova (1977). "Electrical and viscosity properties of mineral oil components". Chemistry and Technology of Fuels and Oils (Springer New York) 13 (7): 479. doi:10.1007/BF00730107.
  9. ↑ Oommen, T.V. (2002). "Vegetable Oils for Liquid-Filled Transformers". Electrical Insulation Magazine, IEEE 18 (1): 6. doi:10.1109/57.981322.
  10. ↑ Science Daily - Mineral Oil Contamination In Humans: A Health Problem?
  11. ↑ Barbara Ingham (October 2007). "Care and Cleaning of Butcher Blocks and Wooden Cutting Boards" (PDF). Food Safety & Health. University of Wisconsin–Madison. Retrieved 2009-07-12.
  12. ↑ "Mineral Oil Liquid Facts and Comparisons". Wolters Kluwer Health – A to Z Drugs Facts. Drugs.com. 2009-06-03. Retrieved 2009-07-13.
  13. ↑ Cadbury Adams USA, LLC (2010). "Swedish Fish Nutrition Facts".
  14. ↑ 14.0 14.1 WHO Food Additive Monograph 70.39, retrieved 20 Sep 2009
  15. ↑ "Best Method for Treating a Butcher Block Counter Top". oldtownhome.com. 2012-11-14. Retrieved 2015-03-31.
  16. ↑ "Optimizing Natural Fertility" (PDF). Retrieved 2013-11-11.
  17. ↑ John Tucker. "Oiling Chips FAQ". Poker Chip Reviews. Retrieved 2009-07-13.
  18. ↑ "Economic Data on Candle and Incense Production and Sales" (PDF). EPA Report: Candles and Incense As Potential Sources of Indoor Air Pollution: Market Analysis And Literature Review. United States Environmental Protection Agency. January 2001. Retrieved 2010-10-11. Gel candles use liquids such as mineral oil, terpene-type chemicals, or modified hydrocarbons as their primary fuel.
  19. ↑ John Bach (2007-05-05). "Mineral Oil Submerged Computer". Puget Custom Computers. Retrieved 2009-07-13.
  20. ↑ Patrick Norton; Roger Chang (2009-03-09). "How to Build an Oil-Cooled Aquarium PC". Revision3. Retrieved 2009-07-13.

External links