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 Washing is a method of cleaning, usually with water and soap or detergent. Washing and then rinsing both body and clothing is an essential part of good hygiene and health. Often people use soaps and detergents to assist in the emulsification o ...

, bathing, and other types of

housekeeping Housekeeping is the management and routine support activities of running an organised physical institution occupied or used by people, like a house, ship, hospital or factory, such as tidying, cleaning, cooking, routine maintenance, shopping, ...

. In industrial settings, soaps are used as

thickener A thickening agent or thickener is a substance which can increase the viscosity of a liquid without substantially changing its other properties. Edible thickeners are commonly used to thicken sauces, soups, and puddings without altering their t ...

s, components of some lubricants, and precursors to catalysts. When used for cleaning, soap solubilizes particles and grime, which can then be separated from the article being cleaned. In

hand washing Hand washing (or handwashing), also known as hand hygiene, is the act of cleaning one's hands with soap or handwash and water to remove viruses/bacteria/microorganisms, dirt, grease, or other harmful and unwanted substances stuck to the hands ...

, as a surfactant, when lathered with a little water, soap kills microorganisms by disorganizing their membrane

lipid bilayer The lipid bilayer (or phospholipid bilayer) is a thin polar membrane made of two layers of lipid molecules. These membranes are flat sheets that form a continuous barrier around all cells. The cell membranes of almost all organisms and many vir ...

and denaturing their

protein Proteins are large biomolecules and macromolecules that comprise one or more long chains of amino acid residues. Proteins perform a vast array of functions within organisms, including catalysing metabolic reactions, DNA replication, res ...

s. It also

emulsifies An emulsion is a mixture of two or more liquids that are normally immiscible (unmixable or unblendable) owing to liquid-liquid phase separation. Emulsions are part of a more general class of two-phase systems of matter called colloids. Although ...

oils, enabling them to be carried away by running water. Soap is created by mixing fats and oils with a base. A similar process is used for making detergent which is also created by combining chemical compounds in a mixer. Humans have used soap for millennia. Evidence exists for the production of soap-like materials in ancient Babylon around 2800 BC.

Types

Since they are salts of fatty acids, soaps have the general formula ( RCO₂⁻)_nMⁿ⁺ (Where R is an alkyl, M is a metal and n is the charge of the cation). The major classification of soaps is determined by the identity of Mⁿ⁺. When M is Na (Sodium) or K (Potassium), the soaps are called toilet soaps, used for handwashing. Many metal dications ( Mg²⁺, Ca²⁺, and others) give

metallic soap A metallic soap is a metallic salt of a fatty acid. Theoretically, soaps can be made of any metal, although not all enjoy practical uses. Varying the metal can strongly affect the properties of the compound, particularly its solubility. Alkali, a ...

. When M is Li, the result is lithium soap (e.g., lithium stearate), which is used in high-performance greases. A cation from an

organic base An organic base is an organic compound which acts as a base. Organic bases are usually, but not always, proton acceptors. They usually contain nitrogen atoms, which can easily be protonated. For example, amines or nitrogen-containing heterocyclic ...

such as ammonium can be used instead of a metal; ammonium

nonanoate Pelargonic acid, also called nonanoic acid, is an organic compound with structural formula CH3(CH2)7CO2H. It is a nine-carbon fatty acid. Nonanoic acid is a colorless oily liquid with an unpleasant, rancid odor. It is nearly insoluble in water, ...

is an ammonium-based soap that is used as an herbicide. Unlike detergents, when used in

hard water Hard water is water that has high mineral content (in contrast with "soft water"). Hard water is formed when water percolates through deposits of limestone, chalk or gypsum, which are largely made up of calcium and magnesium carbonates, bicarbo ...

soap does not lather well and a scum of stearate, a common ingredient in soap, forms as an insoluble precipitate.

Non-toilet soaps

Soaps are key components of most lubricating greases and thickeners. Greases are usually emulsions of calcium soap or lithium soap and mineral oil. Many other metallic soaps are also useful, including those of aluminium, sodium, and mixtures thereof. Such soaps are also used as thickeners to increase the viscosity of oils. In ancient times, lubricating greases were made by the addition of

lime Lime commonly refers to: * Lime (fruit), a green citrus fruit * Lime (material), inorganic materials containing calcium, usually calcium oxide or calcium hydroxide * Lime (color), a color between yellow and green Lime may also refer to: Botany ...

to olive oil. Metal soaps are also included in modern artists' oil paints formulations as a rheology modifier.

Production of metallic soaps

Most metal soaps are prepared by the hydrolysis of methane into ethanoic acid and fatty acids: :2 RCO₂ H + CaO → (RCO₂)₂ Ca + H₂O

Toilet soaps

In a domestic setting, "soap" usually refers to what is technically called a toilet soap, used for household and personal cleaning. When used for cleaning, soap solubilizes particles and grime, which can then be separated from the article being cleaned. The insoluble oil/fat molecules become associated inside micelles, tiny spheres formed from soap molecules with polar

hydrophilic A hydrophile is a molecule or other molecular entity that is attracted to water molecules and tends to be dissolved by water.Liddell, H.G. & Scott, R. (1940). ''A Greek-English Lexicon'' Oxford: Clarendon Press. In contrast, hydrophobes are ...

(water-attracting) groups on the outside and encasing a

lipophilic Lipophilicity (from Greek λίπος "fat" and φίλος "friendly"), refers to the ability of a chemical compound to dissolve in fats, oils, lipids, and non-polar solvents such as hexane or toluene. Such non-polar solvents are themselves lipo ...

(fat-attracting) pocket, which shields the oil/fat molecules from the water making it soluble. Anything that is soluble will be washed away with the water. MicelleColor

Production of toilet soaps

The production of toilet soaps usually entails

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 triglycerides, which are vegetable or animal oils and fats. An alkaline solution (often

lye A lye is a metal hydroxide traditionally obtained by leaching wood ashes, or a strong alkali which is highly soluble in water producing caustic basic solutions. "Lye" most commonly refers to sodium hydroxide (NaOH), but historically has been u ...

or sodium hydroxide) induces saponification whereby the triglyceride fats first hydrolyze into salts of fatty acids. Glycerol (glycerin) is liberated. The glycerin can remain in the soap product as a softening agent, although it is sometimes separated.Cavitch, Susan Miller. ''The Natural Soap Book''. Storey Publishing, 1994 . The type of alkali metal used determines the kind of soap product. Sodium soaps, prepared from sodium hydroxide, are firm, whereas potassium soaps, derived from potassium hydroxide, are softer or often liquid. Historically, potassium hydroxide was extracted from the ashes of bracken or other plants. Lithium soaps also tend to be hard. These are used exclusively in greases. For making toilet soaps, triglycerides (oils and fats) are derived from coconut, olive, or palm oils, as well as tallow.David J. Anneken, Sabine Both, Ralf Christoph, Georg Fieg, Udo Steinberner, Alfred Westfechtel "Fatty Acids" in Ullmann's ''Encyclopedia of Industrial Chemistry'' 2006, Wiley-VCH, Weinheim. Triglyceride is the chemical name for the tri esters of fatty acids and

glycerin Glycerol (), also called glycerine in British English and glycerin in American English, is a simple triol compound. It is a colorless, odorless, viscous liquid that is sweet-tasting and non-toxic. The glycerol backbone is found in lipids known ...

. Tallow, ''i.e.,'' rendered fat, is the most available triglyceride from animals. Each species offers quite different fatty acid content, resulting in soaps of distinct feel. The seed oils give softer but milder soaps. Soap made from pure olive oil, sometimes called Castile soap or Marseille soap, is reputed for its particular mildness. The term "Castile" is also sometimes applied to soaps from a mixture of oils, but a high percentage of olive oil.

History

Ancient Middle East

It is uncertain as to who were the first to invent soap. The earliest recorded evidence of the production of soap-like materials dates back to around 2800 BC in ancient Babylon. A formula for making soap was written on a Sumerian clay tablet around 2500 BC; the soap was produced by heating a mixture of oil and wood ash, the earliest recorded chemical reaction, and used for washing woolen clothing. The Ebers papyrus (Egypt, 1550 BC) indicates the ancient Egyptians used soap as a medicine and combined animal fats or vegetable oils with a

soda ash Sodium carbonate, , (also known as washing soda, soda ash and soda crystals) is the inorganic compound with the formula Na2CO3 and its various hydrates. All forms are white, odourless, water-soluble salts that yield moderately alkaline solutions ...

substance called Trona to create their soaps. Egyptian documents mention a similar substance was used in the preparation of wool for weaving. In the reign of Nabonidus (556–539 BC), a recipe for soap consisted of ''uhulu'' shes cypress iland sesame eed oil"for washing the stones for the servant girls". In the Southern Levant, the ashes from barilla plants, such as species of

Salsola ''Salsola'' is a genus of the subfamily Salsoloideae in the family Amaranthaceae. The genus ''sensu stricto'' is distributed in central and southwestern Asia, North Africa, and the Mediterranean. A common name of various members of this genus and ...

, saltwort ('' Seidlitzia rosmarinus'') and ''

Anabasis Anabasis (from Greek ''ana'' = "upward", ''bainein'' = "to step or march") is an expedition from a coastline into the interior of a country. Anabase and Anabasis may also refer to: History * ''Anabasis Alexandri'' (''Anabasis of Alexander''), a ...

'', were used in soap production, known as potash. Traditionally, olive oil was used instead of animal lard throughout the Levant, which was boiled in a copper cauldron for several days. As the boiling progresses, alkali ashes and smaller quantities of quicklime were added, and constantly stirred. In the case of lard, it required constant stirring while kept lukewarm until it began to trace. Once it began to thicken, the brew was poured into a mold and left to cool and harden for two weeks. After hardening, it was cut into smaller cakes. Aromatic herbs were often added to the rendered soap to impart their fragrance, such as

yarrow ''Achillea millefolium'', commonly known as yarrow () or common yarrow, is a flowering plant in the family Asteraceae. Other common names include old man's pepper, devil's nettle, sanguinary, milfoil, soldier's woundwort, and thousand seal. The ...

leaves,

lavender ''Lavandula'' (common name lavender) is a genus of 47 known species of flowering plants in the mint family, Lamiaceae. It is native to the Old World and is found in Cape Verde and the Canary Islands, and from Europe across to northern and easte ...

, germander, etc.

Roman Empire

Pliny the Elder, whose writings chronicle life in the First Century AD, describes soap as ‘an invention of the Gauls'. The word ''sapo'', Latin for soap, likely was borrowed from an early Germanic language and is cognate with Latin ''sebum'', " tallow". It first appears in

Pliny the Elder Gaius Plinius Secundus (AD 23/2479), called Pliny the Elder (), was a Roman author, naturalist and natural philosopher, and naval and army commander of the early Roman Empire, and a friend of the emperor Vespasian. He wrote the encyclopedic ' ...

's account, '' Historia Naturalis'', which discusses the manufacture of soap from tallow and ashes. There he mentions its use in the treatment of scrofulous sores, as well as among the Gauls as a dye to redden hair which the men in Germania were more likely to use than women. The Romans avoided washing with harsh soaps before encountering the milder soaps used by the Gauls around 58 BC.

Aretaeus of Cappadocia Aretaeus ( grc-gre, Ἀρεταῖος) is one of the most celebrated of the ancient Greek physicians. Little is known of his life. He presumably was a native or at least a citizen of Cappadocia, a Roman province in Asia Minor (modern day Tur ...

, writing in the 2nd century AD, observes among "Celts, which are men called Gauls, those alkaline substances that are made into balls ..called ''soap''". The Romans' preferred method of cleaning the body was to massage oil into the skin and then scrape away both the oil and any dirt with a strigil. The standard design is a curved blade with a handle, all of which is made of metal. The 2nd-century AD physician Galen describes soap-making using lye and prescribes washing to carry away impurities from the body and clothes. The use of soap for personal cleanliness became increasingly common in this period. According to Galen, the best soaps were Germanic, and soaps from Gaul were second best.

Zosimos of Panopolis Zosimos of Panopolis ( el, Ζώσιμος ὁ Πανοπολίτης; also known by the Latin name Zosimus Alchemista, i.e. "Zosimus the Alchemist") was a Greco-Egyptian alchemist and Gnostic mystic who lived at the end of the 3rd and beginning ...

, ''circa'' 300 AD, describes soap and soapmaking.

Ancient China

A detergent similar to soap was manufactured in ancient China from the seeds of Gleditsia sinensis. Another traditional detergent is a mixture of pig pancreas and plant ash called ''zhuyizi'' (). True soap, made of animal fat, did not appear in China until the modern era. Soap-like detergents were not as popular as ointments and creams.

Middle East

Hard toilet soap with a pleasant smell was produced in the Middle East during the Islamic Golden Age, when soap-making became an established industry. Recipes for soap-making are described by Muhammad ibn Zakariya al-Razi (c. 865–925), who also gave a recipe for producing glycerine from olive oil. In the Middle East, soap was produced from the interaction of fatty oils and

fat 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 ...

s with alkali. In Syria, soap was produced using olive oil together with alkali and

. Soap was exported from Syria to other parts of the Muslim world and to Europe. Ahmad Y. al-Hassan (2001)
''Science and Technology in Islam: Technology and applied sciences'', pages 73-74
,

UNESCO The United Nations Educational, Scientific and Cultural Organization is a specialized agency of the United Nations (UN) aimed at promoting world peace and security through international cooperation in education, arts, sciences and culture. It ...

A 12th-century document describes the process of soap production. It mentions the key ingredient, alkali, which later became crucial to modern chemistry, derived from ''al-qaly'' or "ashes". By the 13th century, the manufacture of soap in the Middle East had become virtually industrialized, with sources in Nablus, Fes, Damascus, and Aleppo.

Medieval Europe

Soapmakers in

Naples Naples (; it, Napoli ; nap, Napule ), from grc, Νεάπολις, Neápolis, lit=new city. is the regional capital of Campania and the third-largest city of Italy, after Rome and Milan, with a population of 909,048 within the city's adminis ...

were members of a

guild A guild ( ) is an association of artisans and merchants who oversee the practice of their craft/trade in a particular area. The earliest types of guild formed as organizations of tradesmen belonging to a professional association. They sometimes ...

in the late sixth century (then under the control of the

Eastern Roman Empire The Byzantine Empire, also referred to as the Eastern Roman Empire or Byzantium, was the continuation of the Roman Empire primarily in its eastern provinces during Late Antiquity and the Middle Ages, when its capital city was Constantin ...

), and in the eighth century, soap-making was well known in Italy and Spain.Anionic and Related Lime Soap Dispersants, Raymond G. Bistline Jr., in ''Anionic Surfactants: Organic Chemistry'', Helmut Stache, ed., Volume 56 of Surfactant science series, CRC Press, 1996, chapter 11, p. 632, . The Carolingian

capitulary A capitulary (Medieval Latin ) was a series of legislative or administrative acts emanating from the Frankish court of the Merovingian and Carolingian dynasties, especially that of Charlemagne, the first emperor of the Romans in the west since t ...

''De Villis'', dating to around 800, representing the royal will of Charlemagne, mentions soap as being one of the products the stewards of royal estates are to tally. The lands of Medieval Spain were a leading soapmaker by 800, and soapmaking began in the

Kingdom of England The Kingdom of England (, ) was a sovereign state on the island of Great Britain from 12 July 927, when it emerged from various History of Anglo-Saxon England, Anglo-Saxon kingdoms, until 1 May 1707, when it united with Kingdom of Scotland, ...

about 1200. Soapmaking is mentioned both as "women's work" and as the produce of "good workmen" alongside other necessities, such as the produce of carpenters, blacksmiths, and bakers. In Europe, soap in the 9th century was produced from animal fats and had an unpleasant smell. This changed when olive oil began to be used in soap formulas instead, after which much of Europe's soap production moved to the Mediterranean olive-growing regions. Hard toilet soap was introduced to Europe by Arabs and gradually spread as a luxury item. It was often perfumed. By the 15th century, the manufacture of soap in the Christendom had become virtually industrialized, with sources in Antwerp, Castile, Marseille,

and

Venice Venice ( ; it, Venezia ; vec, Venesia or ) is a city in northeastern Italy and the capital of the Veneto region. It is built on a group of 118 small islands that are separated by canals and linked by over 400 bridges. The isla ...

15th–18th centuries

In France, by the second half of the 15th century, the semi-industrialized professional manufacture of soap was concentrated in a few centers of Provence— Toulon,

Hyères Hyères (), Provençal Occitan: ''Ieras'' in classical norm, or ''Iero'' in Mistralian norm) is a commune in the Var department in the Provence-Alpes-Côte d'Azur region in southeastern France. The old town lies from the sea clustered arou ...

, and Marseille—which supplied the rest of France. In Marseilles, by 1525, production was concentrated in at least two factories, and soap production at Marseille tended to eclipse the other Provençal centers. English manufacture tended to concentrate in London. Finer soaps were later produced in Europe from the 16th century, using vegetable oils (such as olive oil) as opposed to animal fats. Many of these soaps are still produced, both industrially and by small-scale artisans. Castile soap is a popular example of the vegetable-only soaps derived from the oldest "white soap" of Italy. In 1634 Charles I granted the newly formed Society of Soapmakers a monopoly in soap production who produced certificates from ‘foure Countesses, and five Viscountesses, and divers other Ladies and Gentlewomen of great credite and quality, besides common Laundresses and others’, testifying that ‘the New White Soap washeth whiter and sweeter than the Old Soap’. Industrially manufactured ''bar soaps'' became available in the late 18th century, as advertising campaigns in Europe and America promoted popular awareness of the relationship between cleanliness and health. In modern times, the use of soap has become commonplace in industrialized nations due to a better understanding of the role of

hygiene Hygiene is a series of practices performed to preserve health. According to the World Health Organization (WHO), "Hygiene refers to conditions and practices that help to maintain health and prevent the spread of diseases." Personal hygiene refer ...

in reducing the population size of pathogenic microorganisms. File:Dobbins' medicated toilet soap, advertising, 1869.jpg, Advertising for Dobbins' medicated toilet soap File:Palmolive soap 1922 advertisement ladies home journal.jpeg, A 1922 magazine advertisement for Palmolive Soap File:Liquid antibacterial soap.jpg, Liquid soap

19th century

Until the Industrial Revolution, soapmaking was conducted on a small scale and the product was rough. In 1780, James Keir established a chemical works at

Tipton Tipton is an industrial town in the West Midlands in England with a population of around 38,777 at the 2011 UK Census. It is located northwest of Birmingham. Tipton was once one of the most heavily industrialised towns in the Black Country, w ...

, for the manufacture of alkali from the sulfates of potash and soda, to which he afterwards added a soap manufactory. The method of extraction proceeded on a discovery of Keir's. In 1790,

Nicolas Leblanc Nicolas Leblanc (December 6, 1742 – January 16, 1806) was a French chemist and surgeon who discovered how to manufacture soda ash from common salt. Earlier days Leblanc was born in Ivoy le Pré, Cher, France on 6 December 1742. His fathe ...

discovered how to make alkali from common salt.

Andrew Pears Andrew Pears was an English man, born around 1770, who invented transparent soap. He moved to London in 1789 from his home in Mevagissey, Cornwall, where he had trained as a barber. He opened a barber's shop in the then-fashionable residential ...

started making a high-quality, transparent soap,

Pears soap Pears transparent soap is a British brand of soap first produced and sold in 1807 by Andrew Pears, at a factory just off Oxford Street in London. It was the world's first mass-market translucent soap. Under the stewardship of advertising pionee ...

, in 1807 in London. His son-in-law, Thomas J. Barratt, became the brand manager (the first of its kind) for Pears in 1865. In 1882, Barratt recruited English actress and socialite

Lillie Langtry Emilie Charlotte, Lady de Bathe (née Le Breton, formerly Langtry; 13 October 1853 – 12 February 1929), known as Lillie (or Lily) Langtry and nicknamed "The Jersey Lily", was a British socialite, stage actress and producer. Born on the isla ...

to become the poster-girl for Pears soap, making her the first celebrity to endorse a commercial product. During the Restoration era (February 1665 – August 1714) a soap tax was introduced in England, which meant that until the mid-1800s, soap was a luxury, used regularly only by the well-to-do. The soap manufacturing process was closely supervised by revenue officials who made sure that soapmakers' equipment was kept under lock and key when not being supervised. Moreover, soap could not be produced by small makers because of a law that stipulated that soap boilers must manufacture a minimum quantity of one imperial ton at each boiling, which placed the process beyond the reach of the average person. The soap trade was boosted and deregulated when the tax was repealed in 1853.

William Gossage William Gossage (12 May 1799 – 9 April 1877) was a chemical manufacturer who established a soap making business in Widnes, Lancashire, England. Early life William Gossage was born in the village of Burgh-le-Marsh, Lincolnshire to Thomas and El ...

produced low-priced, good-quality soap from the 1850s.

Robert Spear Hudson Robert Spear Hudson (6 December 1812 – 6 August 1884) was an English businessman who popularised dry soap powder. His company was very successful thanks to both an increasing demand for soap and his unprecedented levels of advertising. After ...

began manufacturing a soap powder in 1837, initially by grinding the soap with a

mortar and pestle Mortar and pestle is a set of two simple tools used from the Stone Age to the present day to prepare ingredients or substances by crushing and grinding them into a fine paste or powder in the kitchen, laboratory, and pharmacy. The ''mortar'' ( ...

. American manufacturer

Benjamin T. Babbitt Benjamin Talbot Babbitt (May 1, 1809 – October 20, 1889) was a self-made American businessman and inventor who amassed a fortune in the soap industry, manufacturing ''Babbitt's Best Soap''. Early life Benjamin Babbitt was born in Westmoreland ...

introduced marketing innovations that included the sale of bar soap and distribution of

product sample A product sample is a sample of a consumer product that is given to the consumer free of cost so that they may try a product before committing to a purchase. Free samples A free sample or "freebie" is a portion of food or other product (for exam ...

William Hesketh Lever William Hesketh Lever, 1st Viscount Leverhulme , (, ; 19 September 1851 – 7 May 1925) was an English industrialist, philanthropist, and politician. Having been educated at a small private school until the age of nine, then at church schools ...

and his brother,

James James is a common English language surname and given name: *James (name), the typically masculine first name James * James (surname), various people with the last name James James or James City may also refer to: People * King James (disambiguati ...

, bought a small soap works in

Warrington Warrington () is a town and unparished area in the borough of the same name in the ceremonial county of Cheshire, England, on the banks of the River Mersey. It is east of Liverpool, and west of Manchester. The population in 2019 was estimat ...

in 1886 and founded what is still one of the largest soap businesses, formerly called Lever Brothers and now called

Unilever Unilever plc is a British multinational consumer goods company with headquarters in London, England. Unilever products include food, condiments, bottled water, baby food, soft drink, ice cream, instant coffee, cleaning agents, energy dri ...

. These soap businesses were among the first to employ large-scale

advertising Advertising is the practice and techniques employed to bring attention to a product or service. Advertising aims to put a product or service in the spotlight in hopes of drawing it attention from consumers. It is typically used to promote a ...

campaigns.

Liquid soap

Liquid soap was not invented until the nineteenth century; in 1865, William Sheppard patented a liquid version of soap. In 1898, B.J. Johnson developed a soap derived from palm and olive oils; his company, the B.J. Johnson Soap Company, introduced " Palmolive" brand soap that same year. This new brand of soap became popular rapidly, and to such a degree that B.J. Johnson Soap Company changed its name to Palmolive. In the early 1900s, other companies began to develop their own liquid soaps. Such products as Pine-Sol and

Tide Tides are the rise and fall of sea levels caused by the combined effects of the gravity, gravitational forces exerted by the Moon (and to a much lesser extent, the Sun) and are also caused by the Earth and Moon orbiting one another. Tide t ...

appeared on the market, making the process of cleaning things other than skin, such as clothing, floors, and bathrooms, much easier. Liquid soap also works better for more traditional or non-machine washing methods, such as using a washboard.

Soap-making for hobbyists

Soap and Detergent manufacturing process 03

A variety of methods are available for hobbyists to make soap. Most soapmakers use processes where the glycerol remains in the product, and the saponification continues for many days after the soap is poured into molds. The glycerol is left during the hot process method, but at the high temperature employed, the reaction is practically completed in the kettle, before the soap is poured into molds. This simple and quick process is employed in small factories all over the world. Handmade soap from the cold process also differs from industrially made soap in that an excess of fat or (Coconut Oil, Cazumbal Process) are used, beyond that needed to consume the alkali (in a cold-pour process, this excess fat is called "superfatting"), and the glycerol left in acts as a moisturizing agent. However, the glycerine also makes the soap softer. The addition of glycerol and processing of this soap produces

glycerin soap Glycerin soaps are soaps that contain glycerol, a component of fat or oil. They are recognizably different from other soaps because they are translucent. The clarity is due to the alignment of the soap molecules, which can be induced through the a ...

. Superfatted soap is more skin-friendly than one without extra fat, although it can leave a "greasy" feel. Sometimes, an

emollient 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 ...

is added, such as

jojoba Jojoba (; botanical name: ''Simmondsia chinensis'')also commonly called goat nut, deer nut, pignut, wild hazel, quinine nut, coffeeberry, and gray box bushis native to the Southwestern United States. ''Simmondsia chinensis'' is the sole specie ...

oil or shea butter.

Sand Sand is a granular material composed of finely divided mineral particles. Sand has various compositions but is defined by its grain size. Sand grains are smaller than gravel and coarser than silt. Sand can also refer to a textural class of s ...

pumice Pumice (), called pumicite in its powdered or dust form, is a volcanic rock that consists of highly vesicular rough-textured volcanic glass, which may or may not contain crystals. It is typically light-colored. Scoria is another vesicular v ...

may be added to produce a scouring soap. The scouring agents serve to remove dead cells from the skin surface being cleaned. This process is called exfoliation. To make

antibacterial An antibiotic is a type of antimicrobial substance active against bacteria. It is the most important type of antibacterial agent for fighting bacterial infections, and antibiotic medications are widely used in the treatment and prevention ...

soap, compounds such as

triclosan Triclosan (sometimes abbreviated as TCS) is an antibacterial and antifungal agent present in some consumer products, including toothpaste, soaps, detergents, toys, and surgical cleaning treatments. It is similar in its uses and mechanism of ac ...

triclocarban Triclocarban (sometimes abbreviated as TCC) is an antibacterial chemical once common in, but now phased out of, personal care products like soaps and lotions. It was originally developed for the medical field. Although the mode of action is unkn ...

can be added. There is some concern that use of antibacterial soaps and other products might encourage

antimicrobial resistance Antimicrobial resistance (AMR) occurs when microbes evolve mechanisms that protect them from the effects of antimicrobials. All classes of microbes can evolve resistance. Fungi evolve antifungal resistance. Viruses evolve antiviral resistance. P ...

in microorganisms.

Gallery

File:African Black Soap.jpg, Dudu-Osun – a popular type of

African black soap black soap, or black soap (also known by various local names such as ''ose dudu'', ''sabulun salo'', and ''ncha nkota''), is a kind of soap originating in West Africa. It is made from the ash of locally harvested African plants and dried peels, w ...

File:Azul e Branco.JPG,

Azul e branco soap Azul e branco (''blue and white''), also known as sabão Offenbach (''Offenbach soap'') or sabão macaco (''monkey soap''), is a type of soap used in Portugal. It is comparable to household soap, but has a rugged texture, bulky shape, lack of odor ...

– a bar of blue-white soap File:Soap P1140887.jpg, Handmade soaps sold at a shop in

France France (), officially the French Republic ( ), is a country primarily located in Western Europe. It also comprises of Overseas France, overseas regions and territories in the Americas and the Atlantic Ocean, Atlantic, Pacific Ocean, Pac ...

File:Savon de Marseille.jpg, Traditional Marseille soap File:Soap Shop, Tübingen (2019).jpg, Modern soap shop in

Tübingen Tübingen (, , Swabian: ''Dibenga'') is a traditional university city in central Baden-Württemberg, Germany. It is situated south of the state capital, Stuttgart, and developed on both sides of the Neckar and Ammer rivers. about one in three ...

(2019) File:Pouring lye into water to make soap.jpg, The

is dissolved in water. File:Wheel Bearing Grease.jpg, Greases for automotive applications contain soaps File:Pexels-pixabay-206299.jpg, Soap on a platter

References

External links

* {{Authority control Anionic surfactants Cleaning products Salts Skin care Bathing