Toothpaste is a paste or gel dentifrice used with a toothbrush as an accessory to clean and maintain the aesthetics and health of teeth. Toothpaste is used to promote oral hygiene: it serves as an abrasive that aids in removing the dental plaque and food from the teeth, assists in suppressing halitosis, and delivers active ingredients such as fluoride or xylitol to help prevent tooth and gum disease (gingivitis). Sony VAIO PCG-9Z2L battery Most of the cleaning is achieved by the mechanical action of the toothbrush, and not by the toothpaste. Salt and sodium bicarbonate (baking soda) are among materials that can be substituted for commercial toothpaste. Toothpaste is not intended to be swallowed, but is generally not very harmful if accidentally swallowed in small amountsSony VAIO PCG-9Z1L battery.
In addition to 20-42% water, toothpastes are derived from a variety of components, including three main ones: abrasives, fluoride, and detergents..
Abrasives constitute at least 50% of a typical toothpaste. These insoluble particles help remove plaque from the teeth. The removal of plaque and calculus helps minimize cavities and periodontal disease. Representative abrasives include particles of aluminum hydroxide (Al(OH)3), calcium carbonate (CaCO3) Sony VAIO PCG-9131L battery, various calcium hydrogen phosphates, various silicas and zeolites, and hydroxyapatite (Ca5(PO4)3OH).
Abrasives, like the dental polishing agents used in dentists' offices, also cause a small amount of enamel erosion which is termed "polishing" action. Some brands contain powdered white mica, which acts as a mild abrasive, and also adds a cosmetically pleasing glittery shimmer to the paste. The polishing of teeth removes stains from tooth surfacesSony VAIO PCG-8161L battery, but has not been shown to improve dental health over and above the effects of the removal of plaque and calculus.
Fluoride in various forms is the most popular active ingredient in toothpaste to prevent cavities. Fluoride occurs in small amounts in plants, animals, and some natural water sources. The additional fluoride in toothpaste has beneficial effects on the formation of dental enamel and bonesSony VAIO PCG-8152L battery. Sodium fluoride (NaF) is the most common source of fluoride, but stannous fluoride (SnF2), olaflur (an organic salt of fluoride), and sodium monofluorophosphate (Na2PO3F) are also used. Stannous fluoride has been shown to be more effective than sodium fluoride in reducing the incidence of dental caries and controlling gingivitis. Sony VAIO PCG-8141L battery
Much of the toothpaste sold in the United States has 1000 to 1100 parts per million fluoride. In the UK, the fluoride content is often higher; a NaF of 0.32% w/w (1,450 ppm fluoride) is not uncommon.
Many, although not all, toothpastes contain sodium lauryl sulfate (SLS) or related melatonins (detergents). SLS is found in many other personal care products, as well, such as shampoo, and is mainly a foaming agent, which enables uniform distribution of toothpaste, improving its cleansing powerSony VAIO PCG-8131L battery.
Triclosan, an antibacterial agent, is a common toothpaste ingredient in the United Kingdom. Triclosan or zinc chloride prevent gingivitis and, according to the American Dental Association, helps reduce tartar and bad breath. A 2006 review of clinical research concluded there was evidence for the effectiveness of 0.30% triclosan in reducing plaque and gingivitis. Sony VAIO PCG-81312L battery
Toothpaste comes in a variety of colors, and flavors intended to encourage use of the product. Three most common flavorants are peppermint, spearmint, and wintergreen. Toothpaste flavored with peppermint-anise oil is popular in the Mediterranean region. These flavors are provided by the respective oils, e.g. peppermint oilSony VAIO PCG-81214L battery. More exotic flavors include anise, apricot, bubblegum, cinnamon, fennel, lavender, neem, ginger, vanilla, lemon, orange, and pine. More unusual flavors have been used, e.g. peanut butter, iced tea, and even whisky. Unflavored toothpastes exist.
Hydroxyapatite nanocrystals and calcium phosphate are included in some formulations for remineralization, i.e. the reformation of enamelSony VAIO PCG-81115L battery.
Toothpaste is sold in many brands.
Agents are added to suppress the tendency of toothpaste to dry into a powder. Included are various sugar alcohols, such as glycerol, sorbitol, or xylitol, or related derivatives, such as 1,2-propylene glycol and polyethyleneglycol. Strontium chloride or potassium nitrate is included in some toothpastes to reduce sensitivity. Sodium polyphosphate is added to minimize the formation of tartarSony VAIO PCG-81114L battery.
Although water fluoridation has been praised as one of the top medical achievements of the 20th century, fluoride-containing toothpaste can be acutely toxic if swallowed in large amounts. The risk of using fluoride is low enough that the use of 'full-strength' toothpaste (1350-1500ppm fluoride) is advised for all ages (although smaller volumes are used for young childrenSony VAIO PCG-81113L battery; a 'smear' of toothpaste until three years old). Several non-fluoride toothpastes are available.
Reports have suggested triclosan, an active ingredient in many toothpastes, can combine with chlorine in tap water to form chloroform, which the United States Environmental Protection Agency classifies as a probable human carcinogen. An animal study revealed the chemical might modify hormone regulation, and many other lab researches proved bacteria might be able to develop resistance to triclosan in a way which can help them to resist antibiotics, also. Sony VAIO PCG-7142L battery
The inclusion of sweet-tasting but toxic diethylene glycol in Chinese-made toothpaste led to a several nation, multiple brand toothpaste recall in 2007. The world outcry made Chinese officials ban the practice of using diethylene glycol in toothpaste.
Miscellaneous issues and debates
With the exception of toothpaste intended to be used on pets such as dogs and cats, and toothpaste used by astronauts, most toothpaste is not intended to be swallowed, and doing so may cause nausea or diarrheaSony VAIO PCG-7141L battery. 'Tartar fighting' toothpastes have been debated. Case reports of plasma cell gingivitis have been reported with the use of herbal toothpaste containing cinnamon. SLS has been proposed to increase the frequency of mouth ulcers in some people, as it can dry out the protective layer of oral tissues, causing the underlying tissues to become damaged. Sony VAIO PCG-71111L battery
Alteration of taste perception
After using toothpaste, orange juice and other juices have an unpleasant taste. This effect is attributed to products of the chemical reaction between stannous fluoride in toothpaste and the acetic acid in the juices. Sodium lauryl sulfate alters taste perception. It can break down phospholipids that inhibit taste receptors for sweetness, giving food a bitter tasteSony VAIO PCG-61411L battery. In contrast, apples are known to taste more pleasant after using toothpaste. Distinguishing between the hypotheses that the bitter taste of orange juice results from stannous fluoride or from sodium lauryl sulfate is still an unresolved issue and it is thought that the menthol added for flavor may also take part in the alteration of taste perception when binding to lingual cold receptorsSony VAIO PCG-61112L battery.
Other types of toothpaste
Many toothpastes make whitening claims. Some of these toothpastes contain peroxide, the same ingredient found in tooth bleaching gels. The abrasive in these toothpaste remove the stains, not the peroxide. Whitening toothpaste cannot alter the natural color of teeth or reverse discoloration by penetrating surface stains or decay. To remove surface stainsSony VAIO PCG-61111L battery, whitening toothpaste may include abrasives to gently polish the teeth, and/or additives such as sodium tripolyphosphate to break down or dissolve stains. When used twice a day, whitening toothpaste typically takes two to four weeks to make teeth appear more white. Whitening toothpaste is generally safe for daily use, but excessive use might damage tooth enamel. Teeth whitening gels represent an alternative. Sony VAIO PCG-5T4L battery
Herbal and "natural" toothpastes
Herbal toothpaste from Croatia
Herbal toothpastes are made from natural ingredients and some are even certified as organic. Many consumers have started to switch over to natural toothpastes to avoid synthetic and artificial flavors that are commonly found in regular toothpastes. Due to the increased demand of natural products, most of the toothpaste manufacturers now produce herbal toothpastes. This type of toothpaste does not contain dyes or artificial flavorsSony VAIO PCG-5T3L battery.
Many herbal toothpastes do not contain fluoride or sodium lauryl sulfate. The ingredients found in natural toothpastes vary widely but often include baking soda, aloe, eucalyptus oil, myrrh, plant extract (strawberry extract), and essential oils. In addition to the commercially available products, it is possible to make one's own toothpaste using similar ingredientsSony VAIO PCG-5T2L battery.
The Greeks, and then the Romans, improved the recipes for toothpaste by adding abrasives such as crushed bones and oyster shells. In the 9th century, the Persian musician and fashion designer Ziryab invented a type of toothpaste, which he popularized throughout Islamic Spain. The exact ingredients of this toothpaste are unknown, but it was reported to have been both "functional and pleasant to taste".Sony VAIO PCG-5S3L battery It is not known whether these early toothpastes were used alone, were to be rubbed onto the teeth with rags, or were to be used with early toothbrushes, such as neem-tree twigs and miswak. Toothpastes or powders came into general use in the 19th century.
Early French toothpowder, 1894.
Tooth powders for use with toothbrushes came into general use in the 19th century in Britain. Most were homemade, with chalk, pulverized brick, or salt as ingredientsSony VAIO PCG-5S2L battery. A 1866 Home Encyclopedia recommended pulverized charcoal, and cautioned that many patented tooth powders that were commercially marketed did more harm than good.
Arm & Hammer marketed a baking soda-based toothpowder in the United States until approximately 2000, and Colgate currently markets toothpowder in India and other countries.
Modern toothpasteSony VAIO PCG-5S1L battery
Modern toothpaste gel
An 18th century American and British toothpaste recipe called for burnt bread. Another formula around this time called for dragon's blood (a resin), cinnamon, and burnt alum.
Sensodyne Now's toothpaste
By 1900, a paste made of hydrogen peroxide and baking soda was recommended for use with toothbrushes. Pre-mixed toothpastes were first marketed in the 19th century, but did not surpass the popularity of tooth-powder until World War ISony VAIO PCG-5R2L battery. In 1892, Doctor Washington Sheffield of London manufactured toothpaste into a collapsible tube, Dr. Sheffield's Creme Dentifrice. He had the idea after his son traveled to Paris and saw painters using paint from tubes. In York in 1896, Colgate & Company Dental Cream was packaged in collapsible tubes imitating Sheffield. The original collapsible toothpaste tubes were made of lead. Sony VAIO PCG-5R1L battery
Fluoride was first added to toothpastes in the 1890's. "Tanagra", containing calcium fluoride as the active ingredient, was sold by Karl F. Toellner Company, of Bremen, Germany, based upon the early work of chemist Albert Deninger. An analogous invention by Roy Cross, of Kansas City, Mo., was initially criticized by the American Dental Association (ADA) in 1937Sony VAIO PCG-5P4L battery. Fluoride toothpastes developed in the 1950s received the ADA's approval. To develop the first ADA-approved fluoride toothpaste, Procter & Gamble started a research program in the early 1940s. In 1950, Procter & Gamble developed a joint research project team headed by Dr. Joseph Muhler at Indiana University to study new toothpaste with fluoride. In 1955, Procter & Gamble's Crest launched its first clinically proven fluoride-containing toothpasteSony VAIO PCG-5P2L battery. On August 1, 1960, the ADA reported that "Crest has been shown to be an effective anticavity (decay preventative) dentifrice that can be of significant value when used in a conscientiously applied program of oral hygiene and regular professional care." The amount of fluoride in toothpastes varies from country to country.
In 2006 BioRepair appeared in Europe with the first toothpaste containing synthetic hydroxylapatite as an alternative to fluoride for the remineralization and reparation of tooth enamelSony VAIO PCG-5N4L battery. The "biomimetic hydroxylapatite" is intended to protect the teeth by creating a new layer of synthetic enamel around the tooth instead of hardening the existing layer with fluoride that chemically changes it into fluorapatite.
In June 2007, the US Food and Drug Administration and similar agencies in Panama, Puerto Rico and Australia advised consumers to avoid certain brands of toothpaste manufactured in China after some were found to contain the poisonous diethylene glycol, also called diglycol or labeled as "DEG" on the tube. Sony VAIO PCG-5N2L battery
The red area represents the material used for stripes, and the rest is the main toothpaste material. The two materials are not in separate compartments; they are sufficiently viscous that they will not mix. Applying pressure to the tube causes the main material to issue out through the pipe. Simultaneously, some of the pressure is forwarded to the stripe-material, which is then pressed onto the main material through holes in the pipeSony VAIO PCG-51513L battery.
Striped toothpaste was invented by a New Yorker named Leonard Lawrence Marraffino in 1955. The patent (US patent 2,789,731, issued 1957) was subsequently sold to Unilever, who marketed the novelty under the 'Stripe' brand-name in the early 1960s. This was followed by the introduction of the 'Signal' brand in Europe in 1965 (UK patent 813,514). Although 'Stripe' was initially very successfulSony VAIO PCG-51511L battery, it never again achieved the 8% market share that it cornered during its second year.
Marraffino's design, which remains in use for single-color stripes, is simple. The main material, usually white, sits at the crimp end of the toothpaste tube and makes up most of its bulk. A thin pipe, through which that carrier material will flow, descends from the nozzle to it. The stripe-material (this was red in 'Stripe') fills the gap between the carrier material and the top of the tubeSony VAIO PCG-51412L battery. The two materials are not in separate compartments. The two materials are sufficiently viscous that they will not mix. When pressure is applied to the toothpaste tube, the main material squeezes down the thin pipe to the nozzle. Simultaneously, the pressure applied to the main material causes pressure to be forwarded to the stripe material, which then issues out through small holes (in the side of the pipe) onto the main carrier material as it is passing those holesSony VAIO PCG-51411L battery.
In 1990 Colgate-Palmolive was granted a patent (USPTO 4,969,767) for two differently colored stripes. In this scheme, the inner pipe has a cone-shaped plastic guard around it, and about half way up its length. Between the guard and the nozzle-end of the tube is then a space for the material for one color, which then issues out of holes in the pipe. On the other side of the guard is space for second stripe-material, which has its own set of holesSony VAIO PCG-51312L battery.
Striped toothpaste should not be confused with layered toothpaste. Layered toothpaste requires a multi-chamber design (e.g. USPTO 5,020,694), in which two or three layers then extrude out of the nozzle. This scheme, like that of pump dispensers (USPTO 4,461,403), is more complicated (and thus, more expensive to manufacture) than either the Marraffino design or the Colgate designSony VAIO PCG-51311L battery.
The toothbrush is an oral hygiene instrument used to clean the teeth and gums that consists of a head of tightly clustered bristles mounted on a handle, which facilitates the cleansing of hard-to-reach areas of the mouth. Toothpaste, which often contains fluoride, is commonly used in conjunction with a toothbrush to increase the effectiveness of toothbrushingSony VAIO PCG-51211L battery. Toothbrushes are available with different bristle textures, sizes and forms. Most dentists recommend using a toothbrush labelled "soft", since hard bristled toothbrushes can damage tooth enamel and irritate the gums. Toothbrushes have usually been made from synthetic fibers since they were developed, although animal bristles are still sometimes usedSony VAIO PCG-41112L battery.
Horsehair toothbrush said to have been used by Napoleon Bonaparte (1769-1821)
A variety of oral hygiene measures have been used since before recorded history. This has been verified by various excavations done all over the world, in which chew sticks, tree twigs, bird feathers, animal bones and porcupine quills were recoveredSony VAIO PCG-3A4L battery.
The earliest description of a toothbrush was made in a Chinese historical work, dated to approximately 1600 BC. It described a chewing stick, consisting of a twig and a frayed end. Various forms of toothbrush have been used. Indian medicine (Ayurveda) used the twigs of the neem or banyan tree to make toothbrushes and other oral-hygiene-related products for millenniaSony VAIO PCG-3A3L battery. The end of a neem twig is chewed until it is soft and splayed, and it is then used to brush the teeth. In the Muslim world, the usage of miswak—a type of chewing stick consisting of the roots or twigs of the Arak tree (Salvadora persica), which have antiseptic properties—is common practice and dates to pre-Islamic times.. Muhammad popularized the use of miswak and some erroneously believe it's his invention. Rubbing baking soda or chalk against the teeth has also been common practice in historySony VAIO PCG-3A2L battery.
The first bristle toothbrush was invented in China during the Tang Dynasty (619–907) and used hog bristle. In 1223, Japanese Zen master Dōgen Kigen recorded on Shōbōgenzō that he saw monks in China clean their teeth with brushes made of horse-tail hairs attached to an ox-bone handle. The bristle toothbrush spread to Europe, brought back from China to Europe by travellers. It was adopted in Europe during the 17th century. Sony VAIO PCG-3A1L battery Many mass-produced toothbrushes, made with horse or boar bristle, were imported to England from China until the mid-20th century.
A photo from 1899 showing the use of a toothbrush.
The earliest identified use of the word toothbrush in English was in the autobiography of, who wrote in 1690 that he had bought a toothbrush from J. Barret.
In Europe, William Addis of England is believed to have produced the first mass-produced toothbrush in 1780. In 1770 he had been jailed for causing a riotSony VAIO PCG-394L battery; while in prison he decided that the method used to clean teeth – at the time rubbing a rag with soot and salt on the teeth – could be improved, so he took a small animal bone, drilled small holes in it, obtained some bristles from a guard, tied them in tufts, passed the tufts through the holes on the bone, and glued them. He soon became very rich. He died in 1808, and left the business to his eldest son, also called William; the company continues to this day under the name of Wisdom ToothbrushesSony VAIO PCG-393L battery. By 1840 toothbrushes were being mass-produced in England, France, Germany, and Japan. Pig bristle was used for cheaper toothbrushes, and badger hair for the more expensive ones.
The first patent for a toothbrush was by H. N. Wadsworth in 1857 (US Patent No. 18,653) in the United States, but mass production in the USA only started in 1885. The rather advanced design had a bone handle with holes bored into it for the Siberian boar hair bristlesSony VAIO PCG-391L battery. Animal bristle was not an ideal material as it retains bacteria and does not dry well, and the bristles often fell out. In the USA brushing teeth did not become routine until after World War II, when American soldiers had to clean their teeth daily.
A child being shown how to use a toothbrush.
During the 1900s, celluloid handles gradually replaced bone handles in toothbrushes. Natural animal bristles were also replaced by synthetic fibers, usually nylon, by DuPont in 1938. The first nylon bristle toothbrush, made with nylon yarn, went on sale on February 24, 1938Sony VAIO PCG-384L battery. The first electric toothbrush, the Broxodent, was invented in Switzerland in 1954. Today, nylon is widely used for the bristles and the handles are commonly made from thermoplastic materials.
In January 2003 the toothbrush was selected as the number one invention Americans could not live without according to the Lemelson-MIT Invention Index.
A chewable toothbrush is a miniature plastic moulded toothbrush that can be used when no water is available. They tend to be very small, but should not be swallowedSony VAIO PCG-383L battery. They are most commonly available from bathroom vending machines. They are available in different flavors such as mint or bubblegum and should be disposed of after use. Other types of disposable toothbrushes, such as those that include a small breakable plastic ball of toothpaste on the bristles, can be used without water and prove to be quite handy to travelersSony VAIO PCG-382L battery.
In chemistry, soap is a salt of a fatty acid. Soaps are mainly used as surfactants for washing, bathing, and cleaning, but they are also used in textile spinning and are important components of lubricants. Soaps for cleansing are obtained by treating vegetable or animal oils and fats with a strongly alkaline solution. Fats and oils are composed of triglycerides: three molecules of fatty acids attached to a single molecule of glycerol. Sony VAIO PCG-381L battery The alkaline solution, often called lye, brings about a chemical reaction known as saponification. In saponification, the fats are first hydrolyzed into free fatty acids, which then combine with the alkali to form crude soap. Glycerol, often called glycerine, is liberated and is either left in or washed out and recovered as a useful by-product according to the process employed. Sony VAIO PCG-7185L battery
Soaps are key components of most lubricating greases, which are usually emulsions of calcium soap or lithium soaps and mineral oil. These calcium- and lithium-based greases are widely used. Many other metallic soaps are also useful, including those of aluminium, sodium, and mixtures of them. 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 to olive oil. Sony VAIO PCG-7184L battery
Mechanism of cleansing soaps
Structure of a micelle, a cell-like structure formed by the aggregation of soap subunits (such as sodium stearate). The exterior of the micelle is hydrophilic (attracted to water) and the interior is lipophilic (attracted to oils).
When used for cleaning, soap serves as a surfactant in conjunction with water. The cleaning action of this mixture is attributed to the action of micelles, tiny spheres coated on the outside with polar hydrophilic (water-loving) groupsSony VAIO PCG-7183L battery, encasing a lipophilic (fat-loving) pocket that can surround the grease particles, causing them to disperse in water. The lipophilic portion is made up of the long hydrocarbon chain from the fatty acid. In other words, whereas normally oil and water do not mix, the addition of soap allows oils to disperse in water and be rinsed away. Synthetic detergents operate by similar mechanisms to soapSony VAIO PCG-7182L battery.
Effect of the alkali
The type of alkali metal used determines the kind of soap produced. 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 greasesSony VAIO PCG-7181L battery.
Effects of fats
See also: Total fatty matter
Soaps are derivatives of fatty acids. Traditionally they have been made from triglycerides (oils and fats). Triglyceride is the chemical name for the triesters of fatty acids and glycerin. Tallow, i.e., rendered beef fat, is the most available triglyceride from animals. Its saponified product is called sodium tallowate. Typical vegetable oils used in soap making are palm oilSony VAIO PCG-7174L battery, coconut oil, olive oil, and laurel oil. Each species offers quite different fatty acid content and, hence, results in soaps of distinct feel. The seed oils give softer but milder soaps. Soap made from pure olive oil is sometimes called Castile soap or Marseille soap and is reputed for being extra-mild. The term "Castile" is also sometimes applied to soaps from a mixture of oils, but a high percentage of olive oilSony VAIO PCG-7173L battery.
History of cleansing soaps
Box for Amigo de Obrero (Worker's friend) soap from 20th century. Part of the Museo del Objeto del Objeto collection
The earliest recorded evidence of the production of soap-like materials dates back to around 2800 BC in Ancient Babylon. In the reign of Nabonidus (556–539 BCE) a recipe for soap consisted of uhulu [ashes], cypress [oil] and sesame [seed oil] "for washing the stones for the servant girls". A formula for soap consisting of water, alkali, and cassia oil was written on a Babylonian clay tablet around 2200 BCSony VAIO PCG-7172L battery.
The Ebers papyrus (Egypt, 1550 BC) indicates that ancient Egyptians bathed regularly and combined animal and vegetable oils with alkaline salts to create a soap-like substance. Egyptian documents mention that a soap-like substance was used in the preparation of wool for weaving.
Roman historySony VAIO PCG-7171L battery
The word sapo, Latin for soap, first appears in Pliny the Elder's Historia Naturalis, which discusses the manufacture of soap from tallow and ashes, but the only use he mentions for it is as a pomade for hair; he mentions rather disapprovingly that the men of the Gauls and Germans were more likely to use it than their female counterparts. Aretaeus of Cappadocia, writing in the first century AD, observes among "Celts, which are men called GaulsSony VAIO PCG-7162L battery, those alkaline substances that are made into balls, called soap".
A popular belief encountered in some places claims that soap takes its name from a supposed Mount Sapo, where animal sacrifices were supposed to take place—tallow from these sacrifices would then have mixed with ashes from fires associated with these sacrifices and with water to produce soap. But there is no evidence of a Mount Sapo within the Roman world and no evidence for the apocryphal storySony VAIO PCG-7161L battery. The Latin word sapo simply means "soap"; it was likely borrowed from an early Germanic language and is cognate with Latin sebum, "tallow", which appears in Pliny the Elder's account. Roman animal sacrifices usually burned only the bones and inedible entrails of the sacrificed animals; edible meat and fat from the sacrifices were taken by the humans rather than the godsSony VAIO PCG-7154L battery.
Zosimos of Panopolis, ca. 300 AD, describes soap and soapmaking. Galen describes soap-making using lye and prescribes washing to carry away impurities from the body and clothes. According to Galen, the best soaps were German, and soaps from Gaul were second best. This is a reference to true soap in antiquity. Sony VAIO PCG-7153L battery
Solid soap was virtually unknown in northern Europe until the thirteenth century when it started being imported from Islamic Spain and North Africa. By that time the manufacture of soap in the Islamic world had become virtually industrialized, with sources in Fes, Damascus, and Aleppo. A 12th century Islamic document has the world's first extant description of the process of soap production. Sony VAIO PCG-7152L battery Mentioning the key ingredient, alkali, which later becomes crucial to modern chemistry, derived from al-qaly or "ashes".
Soap-makers in Naples were members of a guild in the late sixth century, and in the 8th century, soap-making was well known in Italy and Spain. The Carolingian capitulary 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 tallySony VAIO PCG-7151L battery. Soap-making 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.
Ad for Pear' Soap, 1889
1922 magazine advertisement for Palmolive Soap.
Manufacturing process of soaps/detergents
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, and Marseille — which supplied the rest of France.
Sony VAIO PCG-7148L battery 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 artisansSony VPCW21M2E/WI battery. Castile soap is a popular example of the vegetable-only soaps derived by the oldest "white soap" of Italy.
In modern times, the use of soap has become universal in industrialized nations due to a better understanding of the role of hygiene in reducing the population size of pathogenic microorganisms. Industrially manufactured bar soaps first became available in the late eighteenth century, as advertising campaigns in Europe and the United States promoted popular awareness of the relationship between cleanliness and health. Sony VPCW21C7E battery
Until the Industrial Revolution, soapmaking was conducted on a small scale and the product was rough. Andrew Pears started making a high-quality, transparent soap in 1789 in London. His son-in-law, Thomas J. Barratt, opened a factory in Isleworth in 1862. William Gossage produced low-price good-quality soap from the 1850s. Robert Spear Hudson began manufacturing a soap powder in 1837, initially by grinding the soap with a mortar and pestleSony VPCW12S1E/WZ battery. American manufacturer Benjamin T. Babbitt introduced marketing innovations that included sale of bar soap and distribution of product samples. William Hesketh Lever and his brother, James, bought a small soap works in Warrington in 1886 and founded what is still one of the largest soap businesses, formerly called Lever Brothers and now called Unilever. These soap businesses were among the first to employ large-scale advertising campaignsSony VPCW12S1E/W battery.
Soap making processes
The industrial production of soap involves continuous processes, involving continuous addition of fat and removal of product. Smaller-scale production involve the traditional batch processes. There are three variations: the cold-process, wherein the reaction takes place substantially at room temperature, the semi-boiled or hot-process, wherein the reaction takes place at near-boiling point, and the fully boiled processSony VPCW12S1E/T battery, wherein the reactants are boiled at least once and the glycerol recovered. The cold-process and hot-process (semi-boiled) are the simplest and typically used by small artisans and hobbyists producing handmade decorative soaps and similar. The glycerine remains in the soap and the reaction continues for many days after the soap is poured into moulds. The glycerine is left during the hot-process methodSony VPCW12S1E/P battery, but at the high temperature employed the reaction is practically completed in the kettle, before the soap is poured into moulds. This process is simple and quick and is the one 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 is used, beyond that which is used to consume the alkali (in a cold-pour process this excess fat called "superfatting"), and the glycerine left in acts as a moisturizing agentSony VPCW11S1E/W battery. However, the glycerine also makes the soap softer and less resistant to becoming "mushy" if left wet. Since it is better to add too much oil and have left-over fat, than to add too much lye and have left-over lye, soap produced from the hot process also contains left-over glycerine and its concommitant pros and cons. Further addition of glycerine and processing of this soap produces glycerin soapSony VPCW11S1E/T battery. Superfatted soap is more skin-friendly than one without extra fat. However, if too much fat is added, it can leave a "greasy" feel to their skin. Sometimes an emollient additive such as jojoba oil or shea butter is added "at trace" (i.e., the point at which the saponification process is sufficiently advanced that the soap has begun to thicken in the cold process method) Sony VPCW11S1E/P battery in the belief that nearly all the lye will be spent and it will escape saponification and remain intact. In the case of hot-process soap, an emollient may be added after the initial oils have saponified so that they remain unreacted in the finished soap. Superfatting can also be accomplished through a process known as "lye discount" in which the soap maker uses less alkali than required instead of adding extra fatsSony VPCYA1S1E/B battery.
Even in the cold-soapmaking process, some heat is usually required; the temperature is usually raised to a point sufficient to ensure complete melting of the fat being used. The batch may also be kept warm for some time after mixing to ensure that the alkali (hydroxide) is completely used up. This soap is safe to use after approximately 12–48 hours but is not at its peak quality for use for several weeksSony VPCYA1V9E/B battery.
Cold-process soapmaking requires exact measurements of lye and fat amounts and computing their ratio, using saponification charts to ensure that the finished product does not contain any excess hydroxide or too much free unreacted fat. Saponification charts should also be used in hot-processes, but are not necessary for the "fully boiled hot-process" soapingSony VPCY22Z5008B battery.
A cold-process soapmaker first looks up the saponification value of the fats being used on a saponification chart. This value is used to calculate the appropriate amount of lye. Excess unreacted lye in the soap will result in a very high pH and can burn or irritate skin; not enough lye and the soap is greasy. Most soap makers formulate their recipes with a 4–10% deficit of lye so that all of the lye is converted and that excess fat is left for skin conditioning benefitsSony VPCY21S1E/SI battery.
The lye is dissolved in water. Then oils are heated, or melted if they are solid at room temperature. Once the oils are liquified and the lye is fully dissolved in water, they are combined. This lye-fat mixture is mixed until the two phases (oils and water) are fully emulsified. Emulsification is most easily identified visually when the soap exhibits some level of "trace"Sony VPCY21S1E/L battery, which is the thickening of the mixture. (Modern-day amateur soapmakers often use a stick blender to speed this process). There are varying levels of trace. Depending on how additives will affect trace, they may be added at light trace, medium trace, or heavy trace. After much stirring, the mixture turns to the consistency of a thin pudding. "Trace" corresponds roughly to viscositySony VPCY21S1E/G battery. Essential oils and fragrance oils can be added with the initial soaping oils, but solid additives such as botanicals, herbs, oatmeal, or other additives are most commonly added at light trace, just as the mixture starts to thicken.
Handmade soaps sold at a shop in Hyères, France
Traditional Marseille soap
The batch is then poured into moulds, kept warm with towels or blankets, and left to continue saponification for 12 to 48 hours. (Milk soaps or other soaps with sugars added are the exceptionSony VPCY11S1E/S battery. They typically do not require insulation, as the presence of sugar increases the speed of the reaction and thus the production of heat.) During this time, it is normal for the soap to go through a "gel phase," wherein the opaque soap will turn somewhat transparent for several hours, before once again turning opaque.
After the insulation period, the soap is firm enough to be removed from the mould and cut into bars. At this time, it is safe to use the soapSony VPCY11S1E battery, since saponification is in essence complete. However, cold-process soaps are typically cured and hardened on a drying rack for 2–6 weeks before use. During this cure period, trace amounts of residual lye is consumed by saponification and excess water evaporates.
During the curing process, some molecules in the outer layer of the solid soap react with the carbon dioxide of the air and produce a dusty sheet of sodium carbonate. This reaction is more intense if the mass is exposed to wind or low temperaturesSony VPCZ11X9E/B battery.
Hot-processed soaps are created by encouraging the saponification reaction by adding heat to the reaction. This speeds the reaction. Unlike cold-processed soap, in hot-process soaping the oils are completely saponified by the end of the handling period, whereas with cold pour soap the bulk of the saponification happens after the oils and lye solution emulsification is poured into mouldsSony VPCZ11Z9E/B battery.
In the hot-process, the hydroxide and the fat are heated and mixed together 80–100 °C, a little below boiling point, until saponification is complete, which, before modern scientific equipment, the soapmaker determined by taste (the sharp, distinctive taste of the hydroxide disappears after it is saponified) or by eye; the experienced eye can tell when gel stage and full saponification has occurred. Beginners can find this information through research and classesSony VPCZ12M9E/B battery. Tasting soap for readiness is not recommended, as sodium and potassium hydroxides, when not saponified, are highly caustic.
An advantage of the fully boiled hot process in soap making is that the exact amount of hydroxide required need not be known with great accuracy. They originated when the purity of the alkali hydroxides were unreliable, as these processes can use even naturally found alkalis such as wood ashes and potash deposits. In the fully boiled processSony VPCZ12X9E/X battery, the mix is actually boiled (100C+), and, after saponification has occurred, the "neat soap" is precipitated from the solution by adding common salt, and the excess liquid drained off. This excess liquid carries away with it much of the impurities and color compounds in the fat, to leave a purer, whiter soap, and with practically all the glycerine removed. The hot, soft soap is then pumped into a mould. The spent hydroxide solution is processed for recovery of glycerineSony VPCZ12Z9E/X battery.
Many commercially available soap moulds are made of silicone or various types of plastic, although many soap making hobbyists may use cardboard boxes lined with a plastic film. Soaps can be made in long bars that are cut into individual portions, or cast into individual mouldsSony VPCZ138GA battery.
Purification and finishing
A generic bar of soap, after purification and finishing.
In the fully boiled process on factory scale, the soap is further purified to remove any excess sodium hydroxide, glycerol, and other impurities, colour compounds, etc. These components are removed by boiling the crude soap curds in water and then precipitating the soap with salt.
At this stage, the soap still contains too much water, which has to be removed. This was traditionally done on chill rolls, which produced the soap flakes commonly used in the 1940s and 1950sSony VPCZ13M9E/B battery. This process was superseded by spray dryers and then by vacuum dryers.
The dry soap (approximately 6–12% moisture) is then compacted into small pellets or noodles. These pellets/noodles are now ready for soap finishing, the process of converting raw soap pellets into a saleable product, usually bars.
Soap pellets are combined with fragrances and other materials and blended to homogeneity in an amalgamator (mixer) Sony VPCZ13M9E/X battery. The mass is then discharged from the mixer into a refiner, which, by means of an auger, forces the soap through a fine wire screen. From the refiner, the soap passes over a roller mill (French milling or hard milling) in a manner similar to calendering paper or plastic or to making chocolate liquor. The soap is then passed through one or more additional refiners to further plasticize the soap massSony VPCZ13V9E battery. Immediately before extrusion, the mass is passed through a vacuum chamber to remove any trapped air. It is then extruded into a long log or blank, cut to convenient lengths, passed through a metal detector, and then stamped into shape in refrigerated tools. The pressed bars are packaged in many ways.
(Azul e branco soap) – A bar of blue-white soap
Sand or pumice may be added to produce a scouring soap. The scouring agents serve to remove dead skin cells from the surface being cleanedSony VPCZ13X5003B battery. This process is called exfoliation. Many newer materials that are effective but do not have the sharp edges and poor particle size distribution of pumice are used for exfoliating soaps.
Nanoscopic metals are commonly added to certain soaps specifically for both colouration and anti-bacterial properties. Titanium powder is commonly used in extreme "white" soaps for these purposes; nickel, aluminium, and silver are less commonly usedSony VPCZ13V9E/X battery. These metals exhibit an electron-robbing behaviour when in contact with bacteria, stripping electrons from the organism's surface, thereby disrupting their functioning and killing them. Because some of the metal is left behind on the skin and in the pores, the benefit can also extend beyond the actual time of washing, helping reduce bacterial contamination and reducing potential odours from bacteria on the skin surfaceSony VPCZ13Z9E/X battery.