Sodium hydroxide, also known as lye and caustic soda, is a highly caustic substance that is used used in small amounts in cosmetics to establish and hold the pH of a product.Sodium Hydroxide is a extremely important compound in our lives because it has so many uses. It is a very common base used in the chemical industry and is used for many things, many of which occur in our daily lives. One of the most well known uses of Sodium Hydroxide is its use in unclogging drains. It comes in many different brands of drain cleaners, but one of the most common is Drano. It also comes in the form of lye soap which can be used to wash practically anything, from the dishes to your face.
sodium hydroxide structure
At room temperature, sodium hydroxide is a white crystalline odorless solid that absorbs moisture from the air. It is a manufactured substance. Sodium Hydroxide is an inorganic compound used to control the pH levels or serve as a buffering agent in cosmetics and personal care products. It was historically used in the formulation of soaps, but is currently seen in a variety of formulas, including bath products, cleansing products, fragrances, foot powders, hair dyes and colors, makeup, nail products, personal cleanliness products, shampoos, shaving products, depilatories, skin care products, and suntan products, as well as chemical hair straighteners and hair wave sets. It is also a popular ingredient in industrial solvents as a chemical base for soaps, oven cleaners, detergents and drain cleaners because of its ability to dissolve grease, oils, fats and protein based deposits, according to Wikipedia. Less frequently, Sodium Hydroxide is seen as an ingredient in toothpastes.
Sodium Hydroxide is FDA approved, and has received the GRAS (Generally Recognized as Safe) rating as a direct food additive. However, it is primarily used in the washing and chemical peeling of produce. It is approved for use in cosmetics and personal care products in varying concentrations: 5% by weight in nail cuticle solvents, 2% by weight in hair straighteners for general use, 4.5% by weight in hair straighteners for professional use, up to a pH 12.7 in depilatories, and up to pH 11 in other uses as a pH adjuster.
References
https://pubchem.ncbi.nlm.nih.gov/compound/sodium_hydroxide
http://sodiumhydroxide.weebly.com/uses.html
