Cetyl Alcohol, Hexadecanol, Cetanol, Palmityl Alcohol, 1-Hexadecanol, C16 Alcohol, Ethal, Ethol, 36653-82-4

Cetyl Alcohol, Hexadecanol, Cetanol, Palmityl Alcohol, 1-Hexadecanol, C16 Alcohol, Ethal, Ethol, 36653-82-4

CETYL ALCOHOL

1. PRODUCT DEFINITION AND CHEMICAL IDENTITY

Note: Cetyl alcohol is a saturated, primary fatty alcohol with a 16-carbon linear chain. Its amphiphilic nature (a hydrophobic long hydrocarbon chain and a terminal hydrophilic hydroxyl group) makes it a versatile ingredient across cosmetic, pharmaceutical, food, and industrial sectors.

2. PHYSICAL AND CHEMICAL PROPERTIES

3. FUNCTIONAL PROPERTIES AND MECHANISM OF ACTION

Cetyl alcohol plays multiple functional roles in formulations, primarily driven by its amphiphilic structure:

• Co-Emulsifier and Emulsion Stabilizer: As a non-ionic co-emulsifier in oil-in-water (O/W) emulsions, it strengthens the interfacial film formed by the primary emulsifier. Its hydroxyl group orients toward the water phase, while its long hydrocarbon chain embeds in the oil phase, increasing film density and elasticity. This prevents droplet coalescence and enhances long-term stability.

• Viscosity Builder / Consistency Modifier: It swells and forms a three-dimensional crystalline gel network (lamellar phases) within the continuous aqueous phase, trapping the emulsion droplets. This increases the formulation's viscosity, providing a desirable "body" and preventing flow. The rheology can be precisely tuned by adjusting the cetyl alcohol concentration.

• Emollient and Skin Conditioner: Upon application, it forms a thin, lipophilic film on the skin's surface. This film provides an occlusive effect, temporarily reducing transepidermal water loss (TEWL) and moisturizing the stratum corneum. It also fills in gaps between dry, rough skin cells, providing a smooth, soft, and silky skin feel.

• Opacifier: In liquid formulations like shampoos, it contributes a pearlescent or opaque, matte appearance, enhancing the product's visual aesthetics.

4. PRODUCTION METHODOLOGIES

Cetyl alcohol is produced from two primary sources:

A. Natural (Vegetable) Source – Preferred for Cosmetics and Food:

1. Raw Material: Coconut oil or palm kernel oil, rich in palmitic acid (C16:0) triglycerides.

2. Hydrolysis: The oil is split with water under high pressure and temperature to yield glycerol and a free fatty acid mixture.

3. Fractionation: The fatty acid mixture is separated via vacuum fractional distillation to isolate a high-purity palmitic acid (C16:0) fraction.

4. Hydrogenation: Palmitic acid is catalytically hydrogenated (using a copper chromite or zinc oxide catalyst) under high pressure and temperature to convert the carboxylic group (-COOH) to a primary alcohol (-CH₂OH).
   C₁₅H₃₁COOH + 2 H₂ → C₁₅H₃₁CH₂OH + H₂O

5. Purification: The crude cetyl alcohol is further purified by distillation or crystallization.

B. Petrochemical (Synthetic) Source – Ziegler Process:

1. Raw Material: Ethylene gas.

2. Chain Growth: Ethylene is reacted with triethylaluminium under controlled conditions to grow long-chain alkyl aluminium compounds with a broad molecular weight distribution.

3. Oxidation and Hydrolysis: The alkyl aluminium mixture is oxidized and then hydrolyzed to yield a mixture of primary alcohols (C₂ to C₂₀+).

4. Distillation: High-purity cetyl alcohol (C16 fraction) is isolated via precise fractional distillation.

5. SECTORAL APPLICATIONS, USAGE RATES, AND FORMULATION GUIDELINES

6. ALTERNATIVES AND COMPARISON (Fatty Alcohol Family)

7. REGULATORY STATUS, SAFETY, AND STORAGE

• GHS Classification: Not classified as a hazardous substance or mixture under CLP (EC 1272/2008).

• Toxicology: Very low acute oral, dermal, and inhalation toxicity. Not a significant skin or eye irritant at typical use concentrations. Considered to be a very low sensitization potential (non-allergenic). Not carcinogenic, mutagenic, or reprotoxic.

• Cosmetic Use: Listed as a safe cosmetic ingredient by the Cosmetic Ingredient Review (CIR). Approved under EU Cosmetics Regulation (EC 1223/2009).

• Pharmaceutical Use: Official monograph in USP/NF and Ph. Eur. as a safe, multi-functional excipient.

• Food Use: Recognized as Generally Recognized As Safe (GRAS) by the FDA for specific direct food applications (e.g., glazing agent).

• Environmental Fate: Readily biodegradable. When derived from vegetable sources, it is considered a renewable, sustainable ingredient.

• Storage: Store in a cool (<25 °C), dry, and well-ventilated area, away from direct sunlight, extreme heat, and strong odours. Keep containers tightly closed.

• Shelf Life: Typically 2-3 years from the date of manufacture under proper storage conditions.

• Personal Protection: Standard industrial hygiene practices are sufficient (e.g., nitrile gloves, safety goggles for handling molten material).

• Packaging: Typically 25 kg paper/PE multi-wall bags, 500 kg big bags, or bulk tankers.

8. FREQUENTLY ASKED QUESTIONS

Q1: Is cetyl alcohol the same as the alcohol in hand sanitizers?
No. Cetyl alcohol is a fatty, waxy solid. The "alcohol" in sanitizers is ethyl alcohol (ethanol), a volatile, drying liquid. Cetyl alcohol is non-drying and is used to moisturize and soften the skin.

Q2: Will cetyl alcohol dry out my skin or hair?
Absolutely not. As an emollient, it forms a protective layer that prevents moisture loss, leaving the skin and hair feeling smooth, soft, and conditioned. It does not have the drying effect of simple, volatile alcohols.

Q3: Can cetyl alcohol be used in vegan or natural formulations?
Yes, when it is derived from plant-based sources like coconut or palm oil, it is considered vegan-friendly and suitable for natural formulations. It is crucial to verify the source with your supplier.

Q4: Why is cetyl alcohol used together with other fatty alcohols like stearyl alcohol?
Blending fatty alcohols like cetyl (C16) and stearyl (C18) alcohol creates a synergistic effect. This mixture, often sold as cetearyl alcohol, provides a smoother, more spreadable consistency than either component alone and is easier for formulators to work with, often giving a superior skin feel.

9. QUICK REFERENCE TABLE