![Castor oil](https://upload.wikimedia.org/wikipedia/commons/f/fa/Castor_oil.jpg)
Castor oil is a
vegetable oil
Vegetable oils, or vegetable fats, are oils extracted from seeds or from other parts of fruits. Like animal fats, vegetable fats are ''mixtures'' of triglycerides. Soybean oil, grape seed oil, and cocoa butter are examples of seed oils, or fat ...
pressed from
castor bean
''Ricinus communis'', the castor bean or castor oil plant, is a species of perennial flowering plant in the spurge family, Euphorbiaceae. It is the sole species in the monotypic genus, ''Ricinus'', and subtribe, Ricininae. The evolution of ...
s.
It is a colourless or pale yellow liquid with a distinct taste and odor. Its
boiling point
The boiling point of a substance is the temperature at which the vapor pressure of a liquid equals the pressure surrounding the liquid and the liquid changes into a vapor.
The boiling point of a liquid varies depending upon the surrounding envir ...
is and its
density
Density (volumetric mass density or specific mass) is the substance's mass per unit of volume. The symbol most often used for density is ''ρ'' (the lower case Greek letter rho), although the Latin letter ''D'' can also be used. Mathematical ...
is 0.961 g/cm
3. It includes a mixture of
triglyceride
A triglyceride (TG, triacylglycerol, TAG, or triacylglyceride) is an ester derived from glycerol and three fatty acids (from ''tri-'' and ''glyceride'').
Triglycerides are the main constituents of body fat in humans and other vertebrates, as w ...
s in which about 90% of fatty acids are
ricinoleates.
Oleic acid
Oleic acid is a fatty acid that occurs naturally in various animal and vegetable fats and oils. It is an odorless, colorless oil, although commercial samples may be yellowish. In chemical terms, oleic acid is classified as a monounsaturated omega ...
and
linoleic acid
Linoleic acid (LA) is an organic compound with the formula COOH(CH2)7CH=CHCH2CH=CH(CH2)4CH3. Both alkene groups are cis-trans isomerism, ''cis''. It is a fatty acid sometimes denoted 18:2 (n-6) or 18:2 ''cis''-9,12. A linoleate is a salt (chem ...
are the other significant components.
Castor oil and its derivatives are used in the manufacturing of
soap
Soap is a salt of a fatty acid used in a variety of cleansing and lubricating products. In a domestic setting, soaps are surfactants usually used for washing, bathing, and other types of housekeeping. In industrial settings, soaps are use ...
s,
lubricant
A lubricant (sometimes shortened to lube) is a substance that helps to reduce friction between surfaces in mutual contact, which ultimately reduces the heat generated when the surfaces move. It may also have the function of transmitting forces, t ...
s, hydraulic and
brake fluid
Brake fluid is a type of hydraulic fluid used in hydraulic brake and hydraulic clutch applications in automobiles, motorcycles, light trucks, and some bicycles. It is used to transfer force into pressure, and to amplify braking force. It works ...
s,
paint
Paint is any pigmented liquid, liquefiable, or solid mastic composition that, after application to a substrate in a thin layer, converts to a solid film. It is most commonly used to protect, color, or provide texture. Paint can be made in many ...
s,
dyes,
coating
A coating is a covering that is applied to the surface of an object, usually referred to as the substrate. The purpose of applying the coating may be decorative, functional, or both. Coatings may be applied as liquids, gases or solids e.g. Pow ...
s,
ink
Ink is a gel, sol, or solution that contains at least one colorant, such as a dye or pigment, and is used to color a surface to produce an image, text, or design. Ink is used for drawing or writing with a pen, brush, reed pen, or quill. Thicker ...
s, cold-resistant
plastic
Plastics are a wide range of synthetic or semi-synthetic materials that use polymers as a main ingredient. Their plasticity makes it possible for plastics to be moulded, extruded or pressed into solid objects of various shapes. This adaptab ...
s,
wax
Waxes are a diverse class of organic compounds that are lipophilic, malleable solids near ambient temperatures. They include higher alkanes and lipids, typically with melting points above about 40 °C (104 °F), melting to giv ...
es and polishes,
nylon
Nylon is a generic designation for a family of synthetic polymers composed of polyamides ( repeating units linked by amide links).The polyamides may be aliphatic or semi-aromatic.
Nylon is a silk-like thermoplastic, generally made from petro ...
, and
perfume
Perfume (, ; french: parfum) is a mixture of fragrant essential oils or aroma compounds (fragrances), fixatives and solvents, usually in liquid form, used to give the human body, animals, food, objects, and living-spaces an agreeable scent. Th ...
s.
Etymology
The name probably comes from a confusion between the ''
Ricinus
''Ricinus communis'', the castor bean or castor oil plant, is a species of perennial flowering plant in the spurge family, Euphorbiaceae. It is the sole species in the monotypic genus, ''Ricinus'', and subtribe, Ricininae. The evolution of cas ...
'' plant that produces it and another plant, the ''
Vitex agnus-castus
''Vitex agnus-castus'', also called vitex, chaste tree (or chastetree), chasteberry, Abraham's balm, lilac chastetree, or monk's pepper, is a native of the Mediterranean region. It is one of the few temperate-zone species of '' Vitex'', which is ...
''. An alternative etymology, though, suggests that it was used as a replacement for
castoreum
Castoreum is a yellowish exudate from the castor sacs of mature beavers. Beavers use castoreum in combination with urine to scent mark their territory. Both beaver sexes have a pair of castor sacs and a pair of anal glands, located in two cavitie ...
.
Composition
Castor oil is well known as a source of
ricinoleic acid
Ricinoleic acid, formally called 12-hydroxy-9-''cis''-octadecenoic acid is a fatty acid. It is an unsaturated omega-9 fatty acid and a hydroxy acid. It is a major component of the seed oil obtained from mature castor plant (''Ricinus communis' ...
, a
monounsaturated
In nutrition, biology, and chemistry, fat usually means any ester of fatty acids, or a mixture of such compounds, most commonly those that occur in living beings or in food.
The term often refers specifically to triglycerides (triple est ...
, 18-carbon
fatty acid
In chemistry, particularly in biochemistry, a fatty acid is a carboxylic acid with an aliphatic chain, which is either saturated or unsaturated. Most naturally occurring fatty acids have an unbranched chain of an even number of carbon atoms, fr ...
. Among fatty acids, ricinoleic acid is unusual in that it has a
hydroxyl
In chemistry, a hydroxy or hydroxyl group is a functional group with the chemical formula and composed of one oxygen atom covalently bonded to one hydrogen atom. In organic chemistry, alcohols and carboxylic acids contain one or more hydroxy ...
functional group
In organic chemistry, a functional group is a substituent or moiety in a molecule that causes the molecule's characteristic chemical reactions. The same functional group will undergo the same or similar chemical reactions regardless of the rest ...
on the 12th carbon atom. This functional group causes ricinoleic acid (and castor oil) to be more
polar
Polar may refer to:
Geography
Polar may refer to:
* Geographical pole, either of two fixed points on the surface of a rotating body or planet, at 90 degrees from the equator, based on the axis around which a body rotates
* Polar climate, the c ...
than most fats. The chemical reactivity of the alcohol group also allows chemical
derivatization
Derivatization is a technique used in chemistry which converts a chemical compound into a product (the reaction's derivate) of similar chemical structure, called a derivative.
Generally, a specific functional group of the compound participates ...
that is not possible with most other seed oils. Because of its ricinoleic acid content, castor oil is a valuable chemical in feedstocks, commanding a higher price than other seed oils. As an example, in July 2007, Indian castor oil sold for about
US$
The United States dollar (symbol: $; code: USD; also abbreviated US$ or U.S. Dollar, to distinguish it from other dollar-denominated currencies; referred to as the dollar, U.S. dollar, American dollar, or colloquially buck) is the official ...
0.90/kg ($0.41/lb), whereas U.S.
soybean
The soybean, soy bean, or soya bean (''Glycine max'') is a species of legume native to East Asia, widely grown for its edible bean, which has numerous uses.
Traditional unfermented food uses of soybeans include soy milk, from which tofu an ...
,
sunflower
The common sunflower (''Helianthus annuus'') is a large annual forb of the genus ''Helianthus'' grown as a crop for its edible oily seeds. Apart from cooking oil production, it is also used as livestock forage (as a meal or a silage plant), as ...
, and
canola
Close-up of canola blooms
Canola flower
Rapeseed oil is one of the oldest known vegetable oils. There are both edible and industrial forms produced from rapeseed, the seed of several cultivars of the plant family Brassicaceae. Historically, ...
oils sold for about $0.30/kg ($0.14/lb).
Uses
Annually, 270,000–360,000 tonnes (600–800 million pounds) of castor oil are produced for a variety of uses.
Food and preservative
In the food industry, food-grade castor oil is used in food additives, flavorings, candy (e.g.,
polyglycerol polyricinoleate
Polyglycerol polyricinoleate (PGPR), E476, is an emulsifier made from glycerol and fatty acids (usually from castor bean, but also from soybean oil). In chocolate, compound chocolate and similar coatings, PGPR is mainly used with another substa ...
in
chocolate
Chocolate is a food made from roasted and ground cacao seed kernels that is available as a liquid, solid, or paste, either on its own or as a flavoring agent in other foods. Cacao has been consumed in some form since at least the Olmec civ ...
), as a mold inhibitor, and in packaging. Polyoxyethylated castor oil (e.g.,
Kolliphor EL Kolliphor EL, formerly known as Cremophor EL, is the registered trademark of BASF Corp. for its version of polyethoxylated castor oil. It is prepared by reacting 35 moles of ethylene oxide with each mole of castor oil. The resulting product is a mi ...
) is also used in the food industries.
In
India
India, officially the Republic of India (Hindi: ), is a country in South Asia. It is the seventh-largest country by area, the second-most populous country, and the most populous democracy in the world. Bounded by the Indian Ocean on the so ...
,
Pakistan
Pakistan ( ur, ), officially the Islamic Republic of Pakistan ( ur, , label=none), is a country in South Asia. It is the world's List of countries and dependencies by population, fifth-most populous country, with a population of almost 24 ...
, and
Nepal
Nepal (; ne, नेपाल ), formerly the Federal Democratic Republic of Nepal ( ne,
सङ्घीय लोकतान्त्रिक गणतन्त्र नेपाल ), is a landlocked country in South Asia. It is mai ...
, food grains are
preserved by the application of castor oil. It stops
rice
Rice is the seed of the grass species ''Oryza sativa'' (Asian rice) or less commonly ''Oryza glaberrima
''Oryza glaberrima'', commonly known as African rice, is one of the two domesticated rice species. It was first domesticated and grown i ...
,
wheat
Wheat is a grass widely cultivated for its seed, a cereal grain that is a worldwide staple food. The many species of wheat together make up the genus ''Triticum'' ; the most widely grown is common wheat (''T. aestivum''). The archaeologi ...
, and
pulses
In medicine, a pulse represents the tactile arterial palpation of the cardiac cycle (heartbeat) by trained fingertips. The pulse may be palpated in any place that allows an artery to be compressed near the surface of the body, such as at the nec ...
from rotting. For example, the legume
pigeon pea
The pigeon pea (''Cajanus cajan'') is a perennial legume from the family Fabaceae native to the Old World. The pigeon pea is widely cultivated in tropical and semitropical regions around the world, being commonly consumed in South Asia, Southeas ...
is commonly available coated in oil for extended storage.
Traditional medicine
![Scott & Bowne's Palatable Castor Oil](https://upload.wikimedia.org/wikipedia/commons/1/1f/Scott_%26_Bowne%27s_Palatable_Castor_Oil.jpg)
Use of castor oil as a
laxative
Laxatives, purgatives, or aperients are substances that loosen stools and increase bowel movements. They are used to treat and prevent constipation.
Laxatives vary as to how they work and the side effects they may have. Certain stimulant, lubri ...
is attested to in the ''circa'' 1550 BCE
Ebers Papyrus, and was in use several centuries earlier.
Although used in
traditional medicine
Traditional medicine (also known as indigenous medicine or folk medicine) comprises medical aspects of traditional knowledge that developed over generations within the folk beliefs of various societies, including indigenous peoples, before the ...
to induce labor in pregnant women, there is no
clinical evidence that castor oil is effective for dilating the
cervix or inducing labor.
According to the
American Cancer Society
The American Cancer Society (ACS) is a nationwide voluntary health organization dedicated to eliminating cancer. Established in 1913, the society is organized into six geographical regions of both medical and lay volunteers operating in more than ...
, "available scientific evidence does not support claims that castor oil on the skin cures cancer or any other disease."
Skin and hair care
Castor oil has been used in
cosmetic
Cosmetic may refer to:
*Cosmetics, or make-up, substances to enhance the beauty of the human body, apart from simple cleaning
*Cosmetic, an adjective describing beauty, aesthetics, or appearance, especially concerning the human body
*Cosmetic, a t ...
products included in creams and as a
moisturizer
A moisturizer, or emollient, is a cosmetic preparation used for protecting, moisturizing, and lubricating the skin. These functions are normally performed by sebum produced by healthy skin. The word "emollient" is derived from the Latin verb ''m ...
. Small amounts of castor oil are frequently used in cold-process soap to increase lathering in the finished bar. It also has been used to enhance
hair conditioning in other products and for supposed anti-
dandruff
Dandruff is a skin condition that mainly affects the scalp. Symptoms include flaking and sometimes mild itchiness. It can result in social or self-esteem problems. A more severe form of the condition, which includes inflammation of the skin, ...
properties.
Coatings
Castor oil is used as a biobased
polyol
In organic chemistry, a polyol is an organic compound containing multiple hydroxyl groups (). The term "polyol" can have slightly different meanings depending on whether it is used in food science or polymer chemistry. Polyols containing two, thr ...
in the
polyurethane
Polyurethane (; often abbreviated PUR and PU) refers to a class of polymers composed of organic chemistry, organic units joined by carbamate (urethane) links. In contrast to other common polymers such as polyethylene and polystyrene, polyurethan ...
industry. The average functionality (number of
hydroxyl
In chemistry, a hydroxy or hydroxyl group is a functional group with the chemical formula and composed of one oxygen atom covalently bonded to one hydrogen atom. In organic chemistry, alcohols and carboxylic acids contain one or more hydroxy ...
groups per triglyceride molecule) of castor oil is 2.7, so it is widely used as a rigid polyol and in coatings.
[ One particular use is in a polyurethane concrete where a castor-oil emulsion is reacted with an isocyanate (usually polymeric ]methylene diphenyl diisocyanate
Methylene diphenyl diisocyanate (MDI) is an aromatic diisocyanate. Three isomers are common, varying by the positions of the isocyanate groups around the rings: 2,2′-MDI, 2,4′-MDI, and 4,4′-MDI. The 4,4′ isomer is most widely used, and i ...
) and a cement
A cement is a binder, a chemical substance used for construction that sets, hardens, and adheres to other materials to bind them together. Cement is seldom used on its own, but rather to bind sand and gravel ( aggregate) together. Cement mix ...
and construction aggregate
Construction aggregate, or simply aggregate, is a broad category of coarse- to medium-grained particulate material used in construction, including sand, gravel, crushed stone, slag, recycled concrete and geosynthetic aggregates. Aggregates ...
. This is applied fairly thickly as a slurry, which is self-levelling. This base is usually further coated with other systems to build a resilient floor.
Castor oil is not a drying oil
A drying oil is an oil that hardens to a tough, solid film after a period of exposure to air, at room temperature. The oil hardens through a chemical reaction in which the components crosslink (and hence, polymerize) by the action of oxygen (not ...
, meaning that it has a low reactivity with air compared with oils such as linseed oil
Linseed oil, also known as flaxseed oil or flax oil (in its edible form), is a colourless to yellowish oil obtained from the dried, ripened seeds of the flax plant (''Linum usitatissimum''). The oil is obtained by pressing, sometimes followed by ...
and tung oil
Tung oil or China wood oil is a drying oil obtained by pressing the seed from the nut of the tung tree (''Vernicia fordii''). The oil and its use are believed to have originated in ancient China and appear in the writings of Confucius from ab ...
. Dehydration of castor oil yields linoleic acids, which do have drying properties.[ In this process, the OH group on the ricinoleic acid along with a hydrogen from the next carbon atom are removed yielding a double bond which then has oxidative cross-linking properties yielding the drying oil.
]
Precursor to industrial chemicals
Castor oil can react with other materials to produce other chemical compounds that have numerous applications. Transesterification
In organic chemistry, transesterification is the process of exchanging the organic group R″ of an ester with the organic group R' of an alcohol. These reactions are often catalyzed by the addition of an acid or base catalyst. The reaction can ...
followed by steam cracking gives undecylenic acid
Undecylenic acid is an organic compound with the formula CH2=CH(CH2)8CO2H. It is an unsaturated fatty acid. It is a colorless oil. Undecylenic acid is mainly used for the production of Nylon-11 and in the treatment of fungal infections of the s ...
, a precursor to specialized polymer nylon 11 Nylon 11 or Polyamide 11 (PA 11) is a polyamide, bioplastic and a member of the nylon family of polymers produced by the polymerization of 11-aminoundecanoic acid. It is produced from castor beans by Arkema under the trade name Rilsan.
Nylon 11 is ...
, and heptanal
Heptanal or heptanaldehyde is an alkyl aldehyde. It is a colourless liquid with a strong fruity odor, which is used as precursor to components in perfumes and lubricants.
Production
The formation of heptanal in the fractional distillation of cas ...
, a component in fragrances. Breakdown of castor oil in strong base gives 2-octanol, both a fragrance component and a specialized solvent, and the dicarboxylic acid sebacic acid
Sebacic acid is a naturally occurring dicarboxylic acid with the chemical formula . It is a white flake or powdered solid. ''Sebaceus'' is Latin for tallow candle, ''sebum'' is Latin for tallow, and refers to its use in the manufacture of candles. ...
. Hydrogenation of castor oil saturates the alkenes, giving a waxy lubricant.[ Castor oil may be epoxidized by reacting the OH groups with ]epichlorohydrin
Epichlorohydrin (abbreviated ECH) is an organochlorine compound and an epoxide. Despite its name, it is not a halohydrin. It is a colorless liquid with a pungent, garlic-like odor, moderately soluble in water, but miscible with most polar organi ...
to make the triglycidyl ether of castor oil which is useful in epoxy technology. This is available commercially as Heloxy 505.
The production of lithium grease consumes a significant amount of castor oil. Hydrogenation
Hydrogenation is a chemical reaction between molecular hydrogen (H2) and another compound or element, usually in the presence of a catalyst such as nickel, palladium or platinum. The process is commonly employed to reduce or saturate organ ...
and saponification
Saponification is a process of converting esters into soaps and alcohols by the action of aqueous alkali (for example, aqueous sodium hydroxide solutions). Soaps are salts of fatty acids, which in turn are carboxylic acids with long carbon chains. ...
of castor oil yields 12-hydroxystearic acid, which is then reacted with lithium hydroxide
Lithium hydroxide is an inorganic compound with the formula LiOH. It can exist as anhydrous or hydrated, and both forms are white hygroscopic solids. They are soluble in water and slightly soluble in ethanol. Both are available commercially. While ...
or lithium carbonate
Lithium carbonate is an inorganic compound, the lithium salt (chemistry), salt of carbonate with the chemical formula, formula . This white Salt (chemistry), salt is widely used in the processing of metal oxides. It is listed on the World Health O ...
to give high-performance lubricant grease.
Since it has a relatively high dielectric constant
The relative permittivity (in older texts, dielectric constant) is the permittivity of a material expressed as a ratio with the electric permittivity of a vacuum. A dielectric is an insulating material, and the dielectric constant of an insulat ...
(4.7), highly refined and dried castor oil is sometimes used as a dielectric fluid A liquid dielectric is a dielectric material in liquid state. Its main purpose is to prevent or rapidly quench electric discharges. Dielectric liquids are used as electrical insulators in high voltage applications, e.g. transformers, capacitors, hig ...
within high-performance, high-voltage capacitor
A capacitor is a device that stores electrical energy in an electric field by virtue of accumulating electric charges on two close surfaces insulated from each other. It is a passive electronic component with two terminals.
The effect of ...
s.
Lubrication
Vegetable oils such as castor oil are typically unattractive alternatives to petroleum
Petroleum, also known as crude oil, or simply oil, is a naturally occurring yellowish-black liquid mixture of mainly hydrocarbons, and is found in geological formations. The name ''petroleum'' covers both naturally occurring unprocessed crud ...
-derived lubricants because of their poor oxidative
Redox (reduction–oxidation, , ) is a type of chemical reaction in which the oxidation states of substrate change. Oxidation is the loss of electrons or an increase in the oxidation state, while reduction is the gain of electrons or a d ...
stability. Castor oil has better low-temperature viscosity
The viscosity of a fluid is a measure of its resistance to deformation at a given rate. For liquids, it corresponds to the informal concept of "thickness": for example, syrup has a higher viscosity than water.
Viscosity quantifies the inte ...
properties and high-temperature lubrication than most vegetable oils, making it useful as a lubricant in jet, diesel
Diesel may refer to:
* Diesel engine, an internal combustion engine where ignition is caused by compression
* Diesel fuel, a liquid fuel used in diesel engines
* Diesel locomotive, a railway locomotive in which the prime mover is a diesel engin ...
, and racing engines. The viscosity of castor oil at 10 °C is 2,420 centipoise, but it tends to form gums in a short time, so its usefulness is limited to engines that are regularly rebuilt, such as racing engines. Lubricant company Castrol
Castrol is a British oil company that markets industrial and automotive lubricants, offering a wide range of oil, greases and similar products for most lubrication applications. The name ''Castrol'' was originally just the brand name for com ...
took its name from castor oil.
Castor oil has been suggested as a lubricant for bicycle pump
A bicycle pump is a type of positive-displacement air pump specifically designed for inflating bicycle tires. It has a connection or adapter for use with one or both of the two most common types of valves used on bicycles, Schrader or Pre ...
s because it does not degrade natural rubber seals.
Early aviation and aeromodelling
Castor oil was the preferred lubricant for rotary engines, such as the Gnome engine after that engine's widespread adoption for aviation in Europe in 1909. It was used almost universally in rotary-engined Allied aircraft in World War I
World War I (28 July 1914 11 November 1918), often abbreviated as WWI, was one of the deadliest global conflicts in history. Belligerents included much of Europe, the Russian Empire, the United States, and the Ottoman Empire, with fightin ...
. Germany had to make do with inferior ersatz
An ersatz good () is a substitute good, especially one that is considered inferior to the good it replaces. It has particular connotations of wartime usage.
Etymology
''Ersatz'' is a German word literally meaning ''substitute'' or ''replaceme ...
oil for its rotary engines, which resulted in poor reliability.
The methanol
Methanol (also called methyl alcohol and wood spirit, amongst other names) is an organic chemical and the simplest aliphatic alcohol, with the formula C H3 O H (a methyl group linked to a hydroxyl group, often abbreviated as MeOH). It is a ...
-fueled, two-cycle, glow-plug engines used for aeromodelling, since their adoption by model airplane
A model aircraft is a small unmanned aircraft. Many are replicas of real aircraft. Model aircraft are divided into two basic groups: flying and non-flying. Non-flying models are also termed static, display, or shelf models.
Aircraft manufactur ...
hobbyists in the 1940s, have used varying percentages of castor oil as lubricants. It is highly resistant to degradation when the engine has its fuel-air mixture leaned for maximum engine speed. Gummy residues can still be a problem for aeromodelling powerplants lubricated with castor oil, however, usually requiring eventual replacement of ball bearing
A ball bearing is a type of rolling-element bearing that uses balls to maintain the separation between the bearing races.
The purpose of a ball bearing is to reduce rotational friction and support radial and axial loads. It achieves this ...
s when the residue accumulates within the engine's bearing races. One British manufacturer of sleeve-valve
The sleeve valve is a type of valve mechanism for piston engines, distinct from the usual poppet valve. Sleeve valve engines saw use in a number of pre-World War II luxury cars and in the United States in the Willys-Knight car and light truck. T ...
d four-cycle model engines has stated the "varnish" created by using castor oil in small percentages can improve the pneumatic seal of the sleeve valve, improving such an engine's performance over time.
Turkey red oil
Turkey red oil, also called sulphonated (or sulfated) castor oil, is made by adding sulfuric acid to vegetable oils, most notably castor oil.[ It was the first synthetic ]detergent
A detergent is a surfactant or a mixture of surfactants with cleansing properties when in dilute solutions. There are a large variety of detergents, a common family being the alkylbenzene sulfonates, which are soap-like compounds that are more ...
after ordinary soap
Soap is a salt of a fatty acid used in a variety of cleansing and lubricating products. In a domestic setting, soaps are surfactants usually used for washing, bathing, and other types of housekeeping. In industrial settings, soaps are use ...
. It is used in formulating lubricant
A lubricant (sometimes shortened to lube) is a substance that helps to reduce friction between surfaces in mutual contact, which ultimately reduces the heat generated when the surfaces move. It may also have the function of transmitting forces, t ...
s, softeners, and dyeing assistants.
Biodiesel
Castor oil, like currently less expensive vegetable oils, can be used as feedstock in the production of biodiesel
Biodiesel is a form of diesel fuel derived from plants or animals and consisting of long-chain fatty acid esters. It is typically made by chemically reacting lipids such as animal fat (tallow), soybean oil, or some other vegetable oil with ...
. The resulting fuel is superior for cold winters, because of its exceptionally low cloud point
In liquids, the cloud point is the temperature below which a transparent solution undergoes either a liquid-liquid phase separation to form an emulsion or a liquid-solid phase transition to form either a stable sol or a suspension that settles a ...
and pour point
The pour point of a liquid is the temperature below which the liquid loses its flow characteristics.
It is defined as the minimum temperature in which the oil has the ability to pour down from a beaker. In crude oil a high pour point is generall ...
.
Initiatives to grow more castor for energy production, in preference to other oil crops, are motivated by social considerations. Tropical subsistence farmers would gain a cash crop.
Punishment
Some parents punished children with a dose of castor oil. Physicians recommended against the practice because they did not want medicines associated with punishment.
A heavy dose of castor oil could be used as a humiliating punishment for adults. Colonial officials used it in the British Raj
The British Raj (; from Hindi ''rāj'': kingdom, realm, state, or empire) was the rule of the British Crown on the Indian subcontinent;
*
* it is also called Crown rule in India,
*
*
*
*
or Direct rule in India,
* Quote: "Mill, who was himsel ...
(India) to deal with recalcitrant servants. Belgian military officials prescribed heavy doses of castor oil in Belgian Congo
The Belgian Congo (french: Congo belge, ; nl, Belgisch-Congo) was a Belgian colony in Central Africa from 1908 until independence in 1960. The former colony adopted its present name, the Democratic Republic of the Congo (DRC), in 1964.
Colo ...
as a punishment for being too sick to work.
The most famous use as punishment came in Fascist Italy under Benito Mussolini
Benito Amilcare Andrea Mussolini (; 29 July 188328 April 1945) was an Italian politician and journalist who founded and led the National Fascist Party. He was Prime Minister of Italy from the March on Rome in 1922 until his deposition in 194 ...
. It was a favorite tool used by the Blackshirts
The Voluntary Militia for National Security ( it, Milizia Volontaria per la Sicurezza Nazionale, MVSN), commonly called the Blackshirts ( it, Camicie Nere, CCNN, singular: ) or (singular: ), was originally the paramilitary wing of the Nation ...
to intimidate and humiliate their opponents. Political dissident
A dissident is a person who actively challenges an established political or religious system, doctrine, belief, policy, or institution. In a religious context, the word has been used since the 18th century, and in the political sense since the 20th ...
s were force-fed large quantities of castor oil by Fascist squads. This technique was said to have been originated by Gabriele D'Annunzio or Italo Balbo
Italo Balbo (6 June 1896 – 28 June 1940) was an Italian fascist politician and Blackshirts' leader who served as Italy's Marshal of the Air Force, Governor-General of Libya and Commander-in-Chief of Italian North Africa. Due to his young a ...
. Victims of this treatment did sometimes die, as the dehydrating effects of the oil-induced diarrhea often complicated their recovery from the nightstick beatings they also received along with the castor oil; however, even those victims who survived had to bear the humiliation of the laxative effects resulting from excessive consumption of the oil.
Safety
The castor seed contains ricin, a toxic lectin. Heating during the oil extraction process denatures and deactivates the lectin. Harvesting castor beans, though, may not be without risk. The International Castor Oil Association FAQ document states that castor beans contain an allergenic compound called CB1A. This chemical is described as being virtually nontoxic, but has the capacity to affect people with hypersensitivity. The allergen may be neutralized by treatment with a variety of alkaline agents. The allergen is not present in the castor oil itself.
In popular culture
*In the 1922 film, ''Nanook of the North
''Nanook of the North'' is a 1922 American silent film which combines elements of documentary and docudrama, at a time when the concept of separating films into documentary and drama did not yet exist. In the tradition of what would later be c ...
'', Nanook gives one of his sons a spoonful of castor oil, and he enjoys it.
*In the 1934 ''Silly Symphony
''Silly Symphony'' is an American animated series of 75 musical short films produced by Walt Disney Productions from 1929 to 1939. As the series name implies, the ''Silly Symphonies'' were originally intended as whimsical accompaniments to pieces ...
'' short "The Wise Little Hen
''The Wise Little Hen'' is a 1934 Walt Disney's ''Silly Symphony'' cartoon, based on the fable '' The Little Red Hen''. The cartoon features the debut of Donald Duck, dancing to the Sailor's Hornpipe. Donald and his friend Peter Pig try to avoi ...
", Donald Duck
Donald Fauntleroy Duck is a cartoon character created by The Walt Disney Company. Donald is an anthropomorphic white duck with a yellow-orange bill, legs, and feet. He typically wears a sailor shirt and cap with a bow tie. Donald is known fo ...
and Peter Pig pretend to have bellyaches to get out of helping the titular hen plant and harvest corn. When she grows wise to their ruse, she invites the two over for dinner and, rather than corn, gives them a bottle of castor oil for their "bellyaches".
*In the 1939 film ''The Great Man Votes
''The Great Man Votes'' is a 1939 American drama film starring John Barrymore as a widowed professor turned drunkard who has the deciding vote in an election for mayor. It was based on the short story of the same name by Gordon Malherbe Hillman p ...
'', an early scene establishes the loving relationship between the single father played by John Barrymore
John Barrymore (born John Sidney Blyth; February 14 or 15, 1882 – May 29, 1942) was an American actor on stage, screen and radio. A member of the Drew and Barrymore theatrical families, he initially tried to avoid the stage, and briefly att ...
and his two young children. “Socrates and his hemlock!” Pop declares as he downs the cup of coffee laced with a spoonful of castor oil prepared by his daughter (12-year-old Virginia Weidler
Virginia Anna Adeleid Weidler (March 21, 1927 – July 1, 1968) was an American child actress, popular in Hollywood films during the 1930s and 1940s.
Early life and career
Weidler was born on March 21, 1927, in Eagle Rock, Los Angeles County, C ...
), following doctor's orders.
*In the 1943 ''Tom and Jerry
''Tom and Jerry'' is an American Animated cartoon, animated media franchise and series of comedy short films created in 1940 by William Hanna and Joseph Barbera. Best known for its 161 theatrical short films by Metro-Goldwyn-Mayer, the series c ...
'' cartoon short "Baby Puss", Tom Cat
Thomas Jasper "Tom" Cat Sr. is a fictional character and one of the two titular main protagonists (the other being Jerry Mouse) in Metro-Goldwyn-Mayer's series of ''Tom and Jerry'' theatrical animated short films. Created by William Hanna and J ...
, dressed as a baby, is given castor oil by a child as a punishment.
*In the 1949 MGM Tex Avery
Frederick Bean "Tex" Avery (February 26, 1908 – August 26, 1980) was an American animator, cartoonist, director, and voice actor. He was known for directing and producing animated cartoons during the golden age of American animation. His mo ...
cartoon '' The House of Tomorrow,'' the house is shown to have individual medicine cabinets for each member of the family, with “Junior’s” containing a large bottle of castor oil and a spoon.
*In the novel ''It Can't Happen Here
''It Can't Happen Here'' is a 1935 dystopian political novel by American author Sinclair Lewis. It describes the rise of a United States dictator similar to how Adolf Hitler gained power. The novel was adapted into a play by Lewis and John C. Mo ...
'', castor oil is used by American fascist paramilitaries in a reference to the Mussolini regime.
*In the 1986 film '' Stand by Me'', protagonist Gordie tells his friends a story in which castor oil is used to violently disrupt a pie-eating contest.
See also
* Castor wax
Castor wax, also called hydrogenated castor oil, is an opaque, white vegetable wax. It is produced by the hydrogenation of pure castor oil often in the presence of a nickel catalyst to increase the rate of reaction. The hydrogenation of castor oil ...
* List of unproven and disproven cancer treatments
References
Further reading
* – overview of chemical properties and manufacturing of castor oil
External links
*
{{DEFAULTSORT:Castor Oil
Castor oil plant
Ayurvedic medicaments
Laxatives
Non-petroleum based lubricants
Liquid dielectrics
Cosmetics chemicals
Traditional medicine
Triglycerides