Let`s see what Wikipedia can tell us!
Shampoo is a hair care product used for the removal of oils, dirt, skin particles, dandruff, environmental pollutants and other contaminant particles that gradually build up in hair. The goal is to remove the unwanted build-up without stripping out so much sebum as to make hair unmanageable.
Even though most modern shampoos include a conditioning component, shampooing is frequently followed by the use of conditioners which ease combing and styling.
The word shampoo in English is derived from Hindi chāmpo and dates to 1762.The Shampoo itself originated in the eastern regions of the Mughal Empire particularly in the Nawab of Bengal where it was introduced as a head massage, usually consisting of Alkali, natural oils and fragrances. The Shampoo was first introduced in Britain by a Bengali Muslim entrepreneur named Sake Dean Mahomed, he first familiarized the shampoo in Basil Cochrane’s vapour baths while working there in the early 19th century. Later onward’s Sake Dean Mahomed together with his Irish wife, opened “Mahomed’s Steam and Vapour Sea Water Medicated Baths” in Brighton, England. His baths were like Turkish baths where clients received a treatment of champi (shampooing). Very soon due to Sake Dean Mahomed fame as a bathing expert he was appointed ‘Shampooing Surgeon’ to both George IV and William IV.
In the 1860s, the meaning of the word shifted from the sense of massage to that of applying soap to the hair. Earlier, ordinary soap had been used for washing hair. However, the dull film soap left on the hair made it uncomfortable, irritating, and unhealthy looking.
During the early stages of shampoo, English hair stylists boiled shaved soap in water and added herbs to give the hair shine and fragrance. Kasey Hebert was the first known maker of shampoo, and the origin is currently attributed to him. Commercially made shampoo was available from the turn of the 20th century. A 1914 ad for Canthrox Shampoo in American Magazine showed young women at camp washing their hair with Canthrox in a lake; magazine ads in 1914 by Rexall featured Harmony Hair Beautifier and Shampoo.
Originally, soap and shampoo were very similar products; both containing the same naturally derived surfactants, a type of detergent. Modern shampoo as it is known today was first introduced in the 1930s with Drene, the first shampoo with synthetic surfactants.
Shampoo is generally made by combining a surfactant, most often sodium lauryl sulfate and/or sodium laureth sulfate with a co-surfactant, most often cocamidopropyl betaine in water to form a thick, viscous liquid. Other essential ingredients include salt (sodium chloride), which is used to adjust the viscosity, a preservative and fragrance. Other ingredients are generally included in shampoo formulations to maximize the following qualities:
- Pleasing foam
- Easy rinsing
- Minimal skin/eye irritation
- Feels thick and/or creamy
- Pleasant fragrance
- Low toxicity
- Good biodegradability
- Slightly acidic (pH less than 7)
- No damage to hair
Many shampoos are pearlescent. This effect is achieved by addition of tiny flakes of suitable materials, e.g. glycol distearate, chemically derived from stearic acid, which may have either animal or vegetable origins. Glycol distearate is a wax. Many shampoos also include silicone to provide conditioning benefits.
Commonly used ingredients
- Sodium laureth sulfate is derived from coconut oils and is used to soften water and create a lather. There was some concern over this particular ingredient circa 1998 about this chemical being a carcinogen, but that has been disproved.
- Sodium lauryl sulfate
- Sodium Lauroamphoacetate is naturally derived from coconut oils and is used as a cleanser and counter-irritant. This is the ingredient that makes the product tear-free.
- Polysorbate 20 (abbreviated as PEG(20)) is a mild glycol based surfactant that is used to solubilize fragrance oils and essential oils; meaning it causes liquid to spread across and penetrate the surface of a solid (i.e. your hair).
- Polysorbate 80 (abbreviated as PEG(80)) is a glycol used to emulsify (or disperse) oils in water (so the oils don’t float on top like Italian salad dressing).
- PEG-150 Distearate is a simple thickener.
- Citric Acid is naturally derived from citrus fruits and is used as an antioxidant to preserve the oils in the product. While it is a severe eye-irritant, the Sodium Lauroamphoacetate counteracts that property. Citric acid is used to adjust the pH down to approximately 5.5. It is a fairly weak acid which makes the adjustment easier. Shampoos usually are at pH 5.5 because at slightly acidic pH the scales on a hair follicle lay flat making the hair feel smooth and look shiny. It also has a small amount of preservative action. Citric acid as opposed to any other acid will prevent bacterial growth.
- Quaternium-15 is used as a bacterial/fungicidal preservative.
- Polyquaternium-10 has nothing to do with the chemical Quaternium-15. This chemical acts as the conditioning ingredient, providing moisture and fullness to the hair.
- Di-PPG-2 myreth-10 adipate is a water-dispersible emollient that forms clear solutions with surfactant systems
- Methylisothiazolinone or MIT, a powerful biocide and preservative.
Vitamins and amino acids
The effectiveness of vitamins, amino acids and “pro-vitamins” to shampoo is also largely debatable. Vitamins are substances that are essential for chemical processes that occur within the body, chiefly inside living cells and in the bloodstream. They cannot have the same beneficial effects on dead tissues like grown hair. However, the physical properties of some vitamins (like vitamin E oil or panthenol) would have a temporary cosmetic effect on the hair shaft while not having any bioactivity.
The proteins that make up the strand are chains of amino acids connected in very specific sequences, and are tightly packed in interlocking arrangements. Proteins are unable to penetrate the skin or the hair, and even if they stick to the outside of the hair they will not help strengthen it. Amino acids cannot penetrate cells through the skin, either; they may be able to enter the dead strands, but without the complex protein-building machinery of the living cells they will not actually return damaged hair proteins to their undamaged state.
Cosmetic companies have developed shampoos specifically for those who have dandruff. These contain fungicides such as ketoconazole, zinc pyrithione and selenium sulfide which reduce loose dander by killing Malassezia furfur. Coal tar and salicylate derivatives are often used as well
Many companies have also developed color-protection shampoos suitable for colored hair.These are shampoos that contain gentle cleansers, maintaining hair colors to be longlastingly bright and vibrant.
Solid shampoos or shampoo bars use as their surfactants soaps and/or other surfactants conveniently formulated as solids. They have the advantage of being spill-proof, and the disadvantage of being slowly applied, needing to be dissolved in use.
Stiff, non-pourable clear gels to be squeezed from a tube were once popular forms of shampoo, and can be produced by increasing a shampoo’s viscosity. This type of shampoo cannot be spilled, but unlike a solid, it can still be lost down the drain by sliding off wet skin or hair. As an alternative to synthetic detergent gels, soap jelly was formerly made at home by dissolving sodium soap in hot water before being used for shampooing or other purposes, to avoid the problem of slow application of solid shampoos noted above.
Shampoos in the form of pastes or creams were formerly marketed in jars or tubes. The contents were wet but not completely dissolved. They would apply faster than solids and dissolve quickly. Jar contents were prone to contamination by users and hence had to be very well preserved.
Powdered shampoos are designed to work without water. They are typically based on powders such as starch, silica or talc, and are intended to physically absorb excess sebum from the hair before being brushed out. Those with dark hair may prefer to use brown powders such as cocoa or carob powder.
Antibacterial shampoos are often used in veterinary medicine for various conditions, as well as in humans before some surgical procedures.
Shampoo intended for animals may contain insecticides or other medications for treatment of skin conditions or parasite infestations such as fleas or mange. These must never be used on humans. It is equally important to note that while some human shampoos may be harmful when used on animals, any human haircare products that contain active ingredients/drugs (such as zinc in anti-dandruff shampoos) are potentially toxic when ingested by animals. Special care must be taken not to use those products on pets. Cats are at particular risk due to their instinctive method of grooming their fur with their tongues.