Cetearyl alcohol is a common ingredient often found in cosmetic products, leading many to question its safety and impact on hair health. By delving into its chemical properties and functions, we can better understand its role and dispel prevalent misconceptions.
Cetearyl alcohol for hair is a fatty alcohol often incorporated in hair care products to enhance texture and provide moisture. Derived from a mix of cetyl and stearyl alcohols, it acts as a thickener and conditioner, helping to improve hair’s manageability and softness.
Cetearyl alcohol is not in the category of “drying alcohols.” Instead, they can be beneficial for certain hair types. Given its prevalence in hair care products, it’s crucial to understand its chemical composition, safety, and impact on the hair and scalp.
Teaming up with my friend, a hair scientist and cosmetic formulator with a PhD in Chemistry, we’ve crafted a detailed article that delves into the crucial role of cetearyl alcohol in hair care products. This collaboration brings scientific insight to understanding how this ingredient benefits your hair, providing a deeper look into its function and advantages in your hair care routine.
What is Cetearyl Alcohol?
Cetearyl alcohol is a long-chain fatty alcohol commonly found in skincare products, beauty products, and various hair products such as creams, hair masks, hair sprays especially those with a thick consistency.
It originates from a combination of two specific fatty alcohols: cetyl alcohol, which has a straight chain of sixteen carbons (C16), and stearyl alcohol, its counterpart with eighteen carbons (C18).1
Depending on the desired properties, manufacturers adjust the ratio of these two alcohols to produce various grades of cetearyl alcohol. When solid, it presents as a white waxy substance with a notably high melting point.
Exploring Various Types of Alcohols: From Simple to Complex Structures
Alcohols in chemistry refer to organic molecules with a hydroxyl group attached to a carbon chain. Take “Ethyl Alcohol” for instance; it’s the primary component in alcoholic beverages and is a simple alcohol with just two carbon atoms linked to a hydroxyl group.
Contrastingly, cetearyl alcohol has a longer carbon chain, still attached to the hydroxyl group. The longer the carbon chain, the higher the melting point, turning the substance into a waxy solid.
This distinct characteristic is harnessed in personal care products, allowing cetearyl alcohol to add thickness and structure to hair care formulations.
Short-chain alcohols are common types of alcohol used for a variety of purposes. They can also be found in haircare products:
- Ethanol (or ethyl alcohol)
- Isopropanol (or isopropyl alcohol)
- Propanol (or propyl alcohol)
- Alcohol denat (or denatured alcohol)
These ingredients can typically be found in hair mousses, hair sprays, etc. They are known for their quick drying effects. When used in hair products, these alcohols can help the product evaporate quickly from the hair.
However, because of this drying property, they can sometimes lead to dry or frizzy hair if used excessively or in products meant for daily use.
On the other hand, long-chain alcohols, like cetearyl alcohol, have emollient properties which help to moisturize and smooth the hair, counteracting the drying effects of short-chain alcohols.
Source of Cetearyl Alcohol
Currently, cetearyl alcohol is derived primarily from vegetable oils such as, palm and coconut oils. These oils, rich in long-chain fatty acids, are extracted from the kernels of their respective fruits and subsequently purified.
Through chemical processing, these oils are transformed into their corresponding alcohols. Malaysia and Indonesia, prominent in the cultivation of palm and coconut trees, stand as the leading global suppliers of these fatty alcohols.
Role of Cetearyl Alcohol for Hair Care Formulations
Cetearyl alcohol performs several functions in hair care formulations.
1. Enhancing Product Texture and Viscosity with Cetearyl Alcohol
Cetearyl alcohol enhances the texture of emulsion products and increases their viscosity. As a thickening agent, its long carbon chain and high melting point lend products a distinct creamy consistency, offering a unique sensory and tactile experience.2
2. Enhancing Hair Lubrication & Softness with Cetearyl Alcohol
Cetearyl alcohol, with its long carbon chain, offers lubrication to the hair shaft. Its waxy molecules lightly adhere to the hair’s exterior, particularly the cuticular layer, forming a fine protective coating. This coating minimizes friction between hair strands during combing and brushing, promoting smoother hair management.3
3. Moisture Retention with Cetearyl Alcohol
Cetearyl alcohol creates a water-resistant layer on both hair and scalp, helping preserve the hair fiber’s moisture. Beyond softening the hair shaft, it acts as an emollient, reducing water loss from the scalp and hair. This helps maintain hair hydration, combat dryness, and mitigate the drying effect.
4. Emulsion Stability with Cetearyl Alcohol
Is cetearyl alcohol an emulsifier? While cetearyl alcohol isn’t an emulsifying agent on its own, it acts as an effective ingredient as a co-emulsifier, particularly in tandem with non-ionic emulsifiers, to fortify the emulsion’s stability. When added to cream formulations, it refines the emulsion’s particle size, enhancing the product’s texture and ease of application on hair, skin, and scalp.
Stability and Safety of Cetearyl Alcohol in Cosmetics
Cetearyl alcohol, like other fatty alcohols, remains stable over time. It doesn’t oxidize in air and maintains its color and odor throughout the product’s shelf life. In 1988, under the guidance of the drug administration, the Cosmetic Ingredient Review (CIR) Expert Panel evaluated cetearyl alcohol’s safety in cosmetic applications.4
Their report affirmed its safety, noting no concerns about its use in hair and skin care products, even for those with sensitive skin. Furthermore, no irritation, allergic reaction, or related discomfort was observed when applied directly to the skin, scalp, or sensitive skin areas.
Short-Chain Fatty Alcohols vs. Long-Chain Fatty Alcohols
The length of a fatty alcohol’s carbon chain plays a pivotal role in determining its physical and chemical attributes, which in turn affects the texture and viscosity of cream formulations.
Apart from cetearyl alcohol, various types of alcohol, especially short-chain fatty alcohols like lauryl alcohol and myristyl alcohol, are often incorporated into hair care products. Their chemical structures are detailed below.
The viscosity of a cream emulsion is closely tied to the length of its fatty alcohol’s carbon chain. As this chain lengthens, the molecular weight and melting point of the alcohol both rise.
Fatty alcohols, especially long-chain alcohols with chains of twelve carbons (C12) or longer, are solid, while those with shorter chains remain liquid at room temperature.
This is why long chain alcohols yield emulsion products that are firm, thick, and viscous, boasting excellent lubrication and superior resilience to washing.
Final Words
Frequently found in in the ingredient list of hair care creams, styling lotions, and other emulsion products, cetearyl alcohol is a specific type of alcohol known as a long-chain fatty alcohol. It serves as a co-emulsifier, working in tandem with primary emulsifiers to ensure stability.
Beyond adding structure and enhancing viscosity, this hydrophobic wax coats the hair and scalp, providing lubrication, smoothness, and softness. Notably, its use is deemed safe, posing no irritation or discomfort to either the scalp or skin.
References
- Noweck, K.; Grafahrend, W., Ullmann’s Encyclopedia of Industrial Chemistry. In Fatty Alcohols, John Wiley & Sons: 2003. ↩︎
- Zhoh, C.-K.; Lee, K.-Y.; Kim, D.-N., The influences of fatty alcohol and fatty acid on rheological properties of O/W emulsion. Journal of the Society of Cosmetic Scientists of Korea 2009, 35 (2), 103-110. ↩︎
- Schueller, R.; Romanowski, P., Conditioning Agents for Hair and Skin. Taylor & Francis: 1999. ↩︎
- Elder, R., Final report on the safety assessment of cetearyl alcohol, cetyl alcohol, isostearyl alcohol, myristyl alcohol, and behenyl alcohol. J Am Coll Toxicol 1988, 7 (3), 359-413. ↩︎
