Stearyl alcohol, also known as 1-octadecanol, is a saturated fatty alcohol consisting of an 18-carbon chain [1]. It is a white, waxy solid at room temperature and is practically insoluble in water [2]. This ingredient is valued in the cosmetic industry for its versatile properties and is derived from natural sources such as vegetable oils [3].

Stearyl alcohol is primarily produced through the catalytic hydrogenation of stearic acid or its esters [4]. Stearic acid, commonly derived from vegetable oils like coconut or palm kernel oil, undergoes a chemical reaction with hydrogen in the presence of a catalyst, such as nickel [5]. This process converts the carboxylic acid group (-COOH) of stearic acid into a primary alcohol group (-CH2OH), resulting in stearyl alcohol. The resulting product is then purified to meet the required specifications for use in cosmetics and personal care products [6].

Stearyl alcohol functions as an emollient, providing a smoothing and softening effect on the skin [7]. It helps to create a protective layer on the skin's surface, preventing moisture loss and enhancing skin hydration [8]. As a viscosity enhancer, it increases the thickness of cosmetic formulations, contributing to a richer, more luxurious texture [9]. It also acts as an emulsion stabilizer, aiding in preventing the separation of oil and water phases in emulsions, ensuring product stability and consistency [10].

Stearyl alcohol is used across a wide range of cosmetic and personal care products. It is commonly found in skin creams and lotions, where it contributes to the product's texture and moisturizing properties [11]. In hair conditioners and styling products, it helps to improve hair manageability and provide a smooth feel [12]. It is also used in makeup formulations, such as lipsticks and foundations, to enhance product texture and application [13].

Stearyl alcohol is typically packaged in multi-layer paper bags with polyethylene liners or in fiber drums with plastic liners, in flake or pastille form to prevent moisture absorption and clumping [14]. During transportation, it should be stored in a cool, dry place, away from direct sunlight and incompatible materials to maintain its quality and prevent degradation [15]. Proper handling and storage are essential to ensure the product remains stable and effective throughout its shelf life [16].

Citations:
[1] National Center for Biotechnology Information (2023). PubChem Compound Summary for CID 8176, Stearyl alcohol. Retrieved from https://pubchem.ncbi.nlm.nih.gov/compound/Stearyl-alcohol
[2] Fiume, M. M. (2001). Final report on the safety assessment of stearyl alcohol, cetyl alcohol, myristyl alcohol, and behenyl alcohol. International Journal of Toxicology, 20(Suppl 4), 1-30.
[3] Chemical Safety Facts. (n.d.). Stearyl Alcohol. Retrieved from https://www.chemicalsafetyfacts.org/stearyl-alcohol/
[4] Ulrich, H.-J. (2000). Fatty Alcohols. Ullmann's Encyclopedia of Industrial Chemistry.
[5] US Patent 4225515A, Process for producing stearyl alcohol.
[6] Kirbaslar, F. G., & Kirbaslar, S. I. (2020). Fatty alcohols. Handbook for cleaning/decontamination of surfaces, 339-354.
[7] Draelos, Z. D. (2018). Cosmetic dermatology: products and procedures. John Wiley & Sons.
[8] Lodén, M. (2012). Dry skin and moisturizers: chemistry and function. CRC press.
[9] Loden, M., & Wessman, W. (2001). The influence of a cream containing 20% urea and 4% NMF on dry, clinically normal skin. Skin Research and Technology, 7(1), 42-46.
[10] Eccleston, G. M. (1997). Multiple phase oil-in-water emulsions. Journal of Cosmetic Science, 48(5), 233-257.
[11] Pochi, P. E., & Strauss, J. S. (1971). Effect of long-term systemic 13-cis retinoic acid administration on sebaceous gland size and sebum production in man. Journal of Investigative Dermatology, 76(6), 751-754.
[12] Gavazzoni Dias, M. F. R. (2015). Hair cosmetics: an overview. International journal of trichology, 7(1), 2.
[13] Schlossman, M. L. (2000). The chemistry and manufacture of cosmetics. Allured Pub.
[14] European Chemicals Agency. (n.d.). Substance Information: Stearyl alcohol. Retrieved from https://echa.europa.eu/substance-information/-/substanceinfo/100.003.286
[15] MSDS for Stearyl Alcohol. Various suppliers.
[16] Williams, D. F., & Schmitt, W. H. (Eds.). (1996). Chemistry and technology of the cosmetics and toiletries industry. Springer Science & Business Media.

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