Shampoo الشامبوان انجليزية

Shampoo الشامبوان انجليزية

Shampoo :  is a hair care product that is used for cleaning hair.

The goal of using shampoo is to remove the unwanted build-up without stripping out so much sebum as to make hair unmanageable.

Composition :

Shampoo is generally made by combining a surfactant, most often sodium lauryl sulfate 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.[17] Other ingredients are generally included in shampoo formulations to maximize the following qualities:

-         pleasing foam

-         ease of rinsing

-         minimal skin and eye irritation

-         thick or creamy feeling

-         pleasant fragrance

-         low toxicity

-         good biodegradability

-         slight acidity (pH less than 7)

-         no damage to hair

-         repair of damage already done 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 :

-         Ammonium chloride

-         Ammonium lauryl sulfate

-         Glycol

-         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 as evidence suggested it might be 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 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 do not float on top like Italian salad dressing).

-         PEG-150 distearate is a simple thickener.

-         Citric acid is produced biochemically 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 lie 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 and fungicidal preservative.

-         Polyquaternium-10 has nothing to do with the chemical quaternium-15; it 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, is a powerful biocide and preservative.

Health risks :

A number of contact allergens are used as ingredients in shampoos, and contact allergy caused by shampoos is well known. Patch testing can identify ingredients to which patients are allergic, after which a physician can help the patient find a shampoo that is free of the ingredient to which they are allergic.

Methylisothiazolinone, or MIT is an ingredient used in many commercial shampoos. MIT and its closely related analog, chloromethylisothiazolinone or CMIT, affect the ability of young or developing neurons to grow processes (axons and dendrites) in tissue culture .

Some studies have shown MIT to be allergenic and cytotoxic, and this has led to some concern over its use.

The CTFA (Cosmetic, Toiletry, and Fragrance Association) and the European Scientific Committee on Cosmetic Products and Non-Food Products Intended for Consumers (SCCNFP) both released reports stating that methylisothiazolinone poses no health risks to humans at the low concentrations (0.01%) used in finished cosmetic products.