Mineral oil
A mineral oil is any of various colorless, odorless, light mixtures of alkane
Alkanes are chemical compounds that consist only of hydrogen and carbon atoms and are bonded exclusively by single bonds without any cycles...

s in the C15 to C40 range from a non-vegetable (mineral) source, particularly a distillate of petroleum
Petroleum or crude oil is a naturally occurring, flammable liquid consisting of a complex mixture of hydrocarbons of various molecular weights and other liquid organic compounds, that are found in geologic formations beneath the Earth's surface. Petroleum is recovered mostly through oil drilling...


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
White oil
White oil is a home made insecticide spray used for controlling a wide range of insect pests in the garden. The spray works by blocking the breathing pores of insects causing suffocation and death...

, liquid paraffin
Liquid paraffin (medicinal)
Medicinal liquid paraffin is a very highly refined mineral white oil used in cosmetics and for medical purposes. This is a UK definition and the term may have different uses in other countries...

, and liquid petroleum.

Most often, mineral oil is a liquid by-product
A by-product is a secondary product derived from a manufacturing process or chemical reaction. It is not the primary product or service being produced.A by-product can be useful and marketable or it can be considered waste....

 of the distillation
Distillation is a method of separating mixtures based on differences in volatilities of components in a boiling liquid mixture. Distillation is a unit operation, or a physical separation process, and not a chemical reaction....

 of petroleum
Petroleum or crude oil is a naturally occurring, flammable liquid consisting of a complex mixture of hydrocarbons of various molecular weights and other liquid organic compounds, that are found in geologic formations beneath the Earth's surface. Petroleum is recovered mostly through oil drilling...

 to produce gasoline
Gasoline , or petrol , is a toxic, translucent, petroleum-derived liquid that is primarily used as a fuel in internal combustion engines. It consists mostly of organic compounds obtained by the fractional distillation of petroleum, enhanced with a variety of additives. Some gasolines also contain...

 and other petroleum-based products from crude oil. A mineral oil in this sense is a transparent, colorless oil composed mainly of alkanes and cyclic 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...

s, related to petroleum jelly
Petroleum jelly
Petroleum jelly, petrolatum, white petrolatum or soft paraffin, CAS number 8009-03-8, is a semi-solid mixture of hydrocarbons , originally promoted as a topical ointment for its healing properties...

 (also known as "white petrolatum"). It has a density of around 0.8 g/cm3. 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:
  • paraffinic oils, based on n-alkanes
  • naphthenic oil
    Naphthenic oil
    Naphthenic oil is a type of mineral oil. In contrast with paraffinic oils, naphthenic oils contain only low to no proportion of n-alkanes, being based on cycloalkanes instead. The low-temperature behavior of naphthenic oils is better than of paraffinic oils, making them suitable for applications...

    s, based on cycloalkane
    Cycloalkanes are types of alkanes that have one or more rings of carbon atoms in the chemical structure of their molecules. Alkanes are types of organic hydrocarbon compounds that have only single chemical bonds in their chemical structure...

  • aromatic oils, based on 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 (not to be confused with essential oil
    Essential oil
    An essential oil is a concentrated hydrophobic liquid containing volatile aroma compounds from plants. Essential oils are also known as volatile oils, ethereal oils or aetherolea, or simply as the "oil of" the plant from which they were extracted, such as oil of clove...



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
White metal
The white metals are any of several light-colored alloys used as a base for plated silverware, ornaments or novelties, as well as any of several lead-base or tin-base alloys used for things like bearings, jewellery, miniature figures, fusible plugs, some medals and metal type.Some of the metals...



In the United States, mineral oil is generally safe for human contact and consumption and has been approved by the FDA in personal care and cosmetic products, as well as for an additive for food to 10 mg/kg of daily consumption. The World Health Organization
World Health Organization
The World Health Organization is a specialized agency of the United Nations that acts as a coordinating authority on international public health. Established on 7 April 1948, with headquarters in Geneva, Switzerland, the agency inherited the mandate and resources of its predecessor, the Health...

 classifies mineral oils (in untreated or lightly treated industrial-grade form) as Group 1 carcinogens to humans. According to a UK news story dated March 2011, mineral oils used in ink can get into foods when they are packed in recycled cardboard. Because of the danger of cancer, manufacturers are to stop using recycled cardboard in packaging.

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.

Potential medical risks

The application of four popular moisturizers increased the incidence of skin cancer in mice who were irradiated twice a week for 20 weeks. A fifth moisturizer, specially prepared without mineral oil and sodium lauryl sulphate, had no such effect. This study may not directly translate to humans as mice have a thin skin and live in the dark, unlike humans whose bodies are accustomed to sun exposure.

Veterinary uses

Certain mineral oils are used in livestock vaccines, as an adjuvant
Immunologic adjuvant
In immunology, an adjuvant is an agent that may stimulate the immune system and increase the response to a vaccine, without having any specific antigenic effect in itself. The word “adjuvant” comes from the Latin word adiuvare, meaning to help or aid...

 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.


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 eyelash
An eyelash or simply lash is one of the hairs that grow at the edge of the eyelid. Eyelashes protect the eye from debris and perform some of the same function as whiskers do on a cat or a mouse in the sense that they are sensitive to being touched, thus providing a warning that an object is near...

es to prevent brittleness and breaking and, in cold cream
Cold cream
Cold cream is an emulsion of water and certain fats, usually including beeswax and various scent agents, designed to smooth skin and remove makeup. The name derives from the cooling feeling that the cream leaves on the skin...

, 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
Acne cosmetica
Acne cosmetica is a term referring to acne caused by or made worse by cosmetics. The mechanism was presumably a chemically induced plugging of the pilosebaceous orifice...

 substances. These lists of comedogenic substances were developed many years ago and are frequently quoted in the dermatological literature.

A study reported 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).

Mechanical, electrical and industrial

Mineral oil is used in a variety of industrial/mechanical capacities as a non-conductive coolant
A coolant is a fluid which flows through a device to prevent its overheating, transferring the heat produced by the device to other devices that use or dissipate it. An ideal coolant has high thermal capacity, low viscosity, is low-cost, non-toxic, and chemically inert, neither causing nor...

 or thermal fluid in electric components as it does not conduct electricity, while simultaneously functioning to displace air and water. Some examples are in transformer
A transformer is a device that transfers electrical energy from one circuit to another through inductively coupled conductors—the transformer's coils. A varying current in the first or primary winding creates a varying magnetic flux in the transformer's core and thus a varying magnetic field...

s where it is known as transformer oil
Transformer oil
Transformer oil or insulating oil is usually a highly-refined mineral oil that is stable at high temperatures and has excellent electrical insulating properties. It is used in oil-filled transformers, some types of high voltage capacitors, fluorescent lamp ballasts, and some types of high voltage...

, and in high voltage switchgear
The term switchgear, used in association with the electric power system, or grid, refers to the combination of electrical disconnects, fuses and/or circuit breakers used to isolate electrical equipment. Switchgear is used both to de-energize equipment to allow work to be done and to clear faults...

 where mineral oil is used as an insulator and as a coolant to disperse switching arcs. The dielectric constant
Dielectric constant
The relative permittivity of a material under given conditions reflects the extent to which it concentrates electrostatic lines of flux. In technical terms, it is the ratio of the amount of electrical energy stored in a material by an applied voltage, relative to that stored in a vacuum...

 of mineral oil ranges from 2.3 at 50 °C to 2.1 at 200 °C.

Electric space heaters sometimes use mineral oil as a heat transfer
Heat transfer
Heat transfer is a discipline of thermal engineering that concerns the exchange of thermal energy from one physical system to another. Heat transfer is classified into various mechanisms, such as heat conduction, convection, thermal radiation, and phase-change transfer...

 oil. Because it is noncompressible, mineral oil is used as a hydraulic fluid
Hydraulic fluid
Hydraulic fluids, also called hydraulic liquids, are the medium by which power is transferred in hydraulic machinery. Common hydraulic fluids are based on mineral oil or water...

 in hydraulic machinery and vehicles. It is also used as a lubricant and a cutting fluid
Cutting fluid
Cutting fluid is a type of coolant and lubricant designed specifically for metalworking and machining processes. There are various kinds of cutting fluids, which include oils, oil-water emulsions, pastes, gels, aerosols , and air or other gases. They may be made from petroleum distillates, animal...

. Light mineral oil is also used in textile
A textile or cloth is a flexible woven material consisting of a network of natural or artificial fibres often referred to as thread or yarn. Yarn is produced by spinning raw fibres of wool, flax, cotton, or other material to produce long strands...

 industries and used as a jute
Jute is a long, soft, shiny vegetable fibre that can be spun into coarse, strong threads. It is produced from plants in the genus Corchorus, which has been classified in the family Tiliaceae, or more recently in Malvaceae....

 batching oil. An often cited limitation of mineral oil is that it is poorly biodegradable; in some applications, vegetable oils
Vegetable fats and oils
Vegetable fats and oils are lipid materials derived from plants. Physically, oils are liquid at room temperature, and fats are solid. Chemically, both fats and oils are composed of triglycerides, as contrasted with waxes which lack glycerin in their structure...

 such as cottonseed oil
Cottonseed oil
Cottonseed oil is a cooking oil extracted from the seeds of cotton plant of various species, mainly Gossypium hirsutum and Gossypium herbaceum...

 or rapeseed oil
Rapeseed , also known as rape, oilseed rape, rapa, rappi, rapaseed is a bright yellow flowering member of the family Brassicaceae...

 may be used instead.

Food preparation

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 board
Cutting board
A cutting board is a durable board on which to place material for cutting. Common is the kitchen cutting board used in preparing food; other types exist for cutting raw materials such as leather or plastic....

s, 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.

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, though it is still found in many candies, including Swedish Fish
Swedish Fish
Swedish Fish is a type of chewy fish-shaped candy. It has been developed with special flavors specifically for the North American market by the Swedish candy producer Malaco, which exports products to North America.-History:...


It is added to some food products as a substitute for fat.

It is sometimes used as a lubricant in enema
An enema is the procedure of introducing liquids into the rectum and colon via the anus. The increasing volume of the liquid causes rapid expansion of the lower intestinal tract, often resulting in very uncomfortable bloating, cramping, powerful peristalsis, a feeling of extreme urgency and...

 preparations, because most of the ingested material is excreted in the stool
Human feces
Human feces , also known as a stool, is the waste product of the human digestive system including bacteria. It varies significantly in appearance, according to the state of the digestive system, diet and general health....

 rather than being absorbed by the body.

It is also used on cooking utensils or to grease cookware and bakeware
Cookware and bakeware
Cookware and bakeware are types of food preparation containers commonly found in the kitchen. Cookware comprises cooking vessels, such as saucepans and frying pans, intended for use on a stove or range cooktop. Bakeware comprises cooking vessels intended for use inside an oven...

 to prevent food from sticking.

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.


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

Disposable razors dipped in mineral oil prevent the accumulation of rust and mineral build-up from tap water.

It is commonly used to create a "wear" effect on new clay poker chips, which can otherwise only be accomplished through prolonged use. The chips are either placed in mineral oil (and left there for a short period of time), or the oil is applied to each chip individually, then rubbed clean. This removes any chalky residue left over from manufacture, and also improves the look and "feel" of the chips.

It is the principal fuel in some types of gel-type scented candles.

Mineral oil has been used to immerse computers in order to absorb heat and cool the system in some custom-built projects.

Veterinarian-grade mineral oil, an inexpensive source for mineral oil, is frequently used by amateur radio
Amateur radio
Amateur radio is the use of designated radio frequency spectrum for purposes of private recreation, non-commercial exchange of messages, wireless experimentation, self-training, and emergency communication...

 operators as coolant in RF dummy loads
Dummy load
A dummy load is a device used to simulate an electrical load, usually for testing purposes.-Radio:In radio this device is also known as a dummy antenna or a radio frequency termination. It is a device used in place of an antenna to aid in testing a radio transmitter...


Pelletizing machines used in food manufacturing and other industries are often cleaned between runs by forcing whole oats moistened with mineral oil through the machine. This method is recommended by the machine's manufacturer.

A folk use of mineral oil (and some skin lotions are rich in it) is in removing some difficult to remove paper labels that some manufacturer or vendors stick on their products.

Mineral oil is sometimes used in fire breathing
Fire breathing
Fire breathing is the act of creating a fireball by breathing a fine mist of fuel over an open flame. Proper technique and the correct fuel create the illusion of danger to enhance the novelty of fire breathing, while reducing the risk to health and safety...


In stonework, mineral oil is often used to polish alabaster.

External links

  • "Safety and Health Guideline for Oil Mist, Mineral Oil", Occupational Safety and Health Administration
    Occupational Safety and Health Administration
    The United States Occupational Safety and Health Administration is an agency of the United States Department of Labor. It was created by Congress of the United States under the Occupational Safety and Health Act, signed by President Richard M. Nixon, on December 29, 1970...

  • Lawrence Livermore National Laboratory – Safe handling of Alkali Metals
  • FAO
    Food and Agriculture Organization
    The Food and Agriculture Organization of the United Nations is a specialised agency of the United Nations that leads international efforts to defeat hunger. Serving both developed and developing countries, FAO acts as a neutral forum where all nations meet as equals to negotiate agreements and...

    Report on food safety of mineral oil, 1970
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