Cetearyl Alcohol and Sodium Cetearyl Sulfate

Overview

This blend is one of the oldest workhorse emulsifying systems in cosmetic manufacture. It is supplied as white, waxy flakes or pastilles with a faint fatty odour, melting around 50-55 C. The composition is roughly 90% cetearyl alcohol (a fatty-alcohol blend of cetyl and stearyl alcohols) and 10% sodium cetearyl sulfate, which is the sulfated sodium salt of the same fatty alcohols.

The cetearyl alcohol provides the bulk of the emulsifier’s structure and viscosity. The sodium cetearyl sulfate provides the anionic surfactant character that allows the wax to emulsify oil into water without any additional emulsifier.

It is a true self-emulsifying wax — meaning a single ingredient handles both the oil-water bridging and the thickening of the finished cream. Shelf life is typically 2-3 years stored cool and dry.

What it does in a formula

The anionic charge on the sodium cetearyl sulfate component does the emulsification work. When the molten wax is mixed into a hot water phase under shear, the negatively charged sulfate ions face the water and the fatty tails face the oil droplets, creating stable oil-in-water emulsion droplets.

The cetearyl alcohol component then crystallises on cooling, forming a liquid-crystal network through the finished cream. That network is what gives the classic dense, rich, “old-school cream” texture associated with this emulsifier.

Final products tend to be thick, white, and opaque, with a substantial cushion on application and a moderately rich after-feel. The skin feel is heavier than modern non-ionic emulsifiers but lighter than a true cold cream.

How to use

Melt into the oil phase at 70-75 C. Combine with the heated water phase and homogenise or stir vigorously until cooled below 40 C. Compatible with most cosmetic actives but the anionic charge means cationic ingredients (such as quaternised conditioning agents) will destabilise the emulsion. Performs best at pH 5-8.

Usage rates by product type:

• Light body lotions: 3-5%
• Medium-bodied creams: 5-8%
• Rich face creams: 8-12%
• Thick body butters (emulsified): 10-15%
• Hand creams: 6-10%
• Hair conditioners (anionic-compatible): 4-8%
• Foot creams: 8-12%

Best for / Worst for

Best for: classic rich creams, traditional cold-cream-style emulsions, hand creams, foot creams, anionic-compatible body lotions, formulas where a thick stable emulsion is the goal.

Worst for: cationic-conditioning hair products, formulas needing a modern light gel-cream feel, very low-pH or very high-pH formulas, products positioned around silky modern texture.

Common pitfalls

Mixing it with cationic ingredients. The anionic charge of the sodium cetearyl sulfate reacts with cationic conditioners (cetrimonium chloride, behentrimonium methosulfate, etc.) and breaks the emulsion. Use a non-ionic emulsifier instead when cationic actives are involved.

Under-dosing for the desired thickness. This emulsifier scales viscosity with use rate. A 3% inclusion gives a thin lotion, while 10% gives a thick cream. Adjust to the target texture rather than treating it as a fixed amount.

Confusing it with non-ionic Emulsifying Wax NF. Several products are sold under the name “Emulsifying Wax NF” — some are anionic (this one), some are non-ionic (Polawax-style blends). The behaviour and compatibility are not interchangeable. Always check the INCI on the label.

Skipping the heat-and-hold. The wax needs to be fully melted and held at 70-75 C while combining with the water phase to form a stable emulsion. Cooler combining temperatures produce grainy or unstable results.

Substitutes

• Cetearyl Alcohol and Polysorbate 60 (Polawax) — non-ionic alternative, more versatile.
• Glyceryl Stearate SE — self-emulsifying single ingredient, lighter.
• Cetearyl Glucoside and Cetearyl Alcohol — natural-positioned non-ionic alternative.
• Olivem 1000 (Cetearyl Olivate and Sorbitan Olivate) — natural alternative with similar richness.