CETEARETH-20, CETETH-2 & CETETH-20: Cosmetic Emulsifier Guide
Ceteareth and Ceteth ingredients are polyethylene glycol ethers of cetyl or cetearyl alcohol — non-ionic surfactants used as emulsifiers, co-emulsifiers, and mild cleansing agents in creams, lotions, hair conditioners, and cleansers. Venus Ethoxyethers manufactures Ceteareth-20, Ceteth-2, and Ceteth-20 for personal care formulators who need reliable O/W emulsion stability and INCI documentation for global markets.
What are Ceteareth and Ceteth?
Ceteth refers to polyethylene glycol ethers of cetyl alcohol (C16 saturated fatty alcohol). Ceteareth refers to ethers of cetearyl alcohol, a blend of cetyl and stearyl alcohols (typically C16–C18). The number after the INCI name — 2, 20, etc. — is the average number of ethylene oxide (EO) units added during ethoxylation.
These compounds are produced by reacting the fatty alcohol with ethylene oxide in a catalytic alkoxylation process. The resulting molecule has a lipophilic fatty chain and a hydrophilic polyoxyethylene tail, making it an amphiphilic non-ionic surfactant.
CETETH-2
| Property | Typical value |
|---|---|
| INCI | CETETH-2 |
| Base alcohol | Cetyl alcohol (C16) |
| Average EO moles | 2 |
| HLB (approx.) | ~5–6 |
| Physical form | Liquid to soft waxy solid |
| Primary function | Co-emulsifier, solubilizer, W/O or lipophilic systems |
Ceteth-2 is a low-HLB, lipophilic emulsifier. It helps dissolve lipophilic ingredients in solvent phases and supports water-in-oil or oil-rich emulsions. In personal care, it appears in hair dyes, permanent-wave systems, and cleansing products where mild surfactant action is needed. It is often combined with high-HLB partners such as Ceteth-20 or Ceteareth-20 to build a complete emulsifier system.
CETETH-20
| Property | Typical value |
|---|---|
| INCI | CETETH-20 |
| Base alcohol | Cetyl alcohol (C16) |
| Average EO moles | 20 |
| HLB (approx.) | ~15 |
| Primary function | O/W emulsifier, surfactant, solubilizer |
Ceteth-20 is a hydrophilic emulsifier suited to oil-in-water creams and lotions. It stabilizes the oil-water interface, helps other ingredients dissolve in aqueous phases, and provides mild cleansing in rinse-off products. The Cosmetic Ingredient Review (CIR) Expert Panel includes Ceteth-20 among Ceteth grades considered safe in present cosmetic practices when formulated to be non-irritating.
CETEARETH-20
| Property | Typical value |
|---|---|
| INCI | CETEARETH-20 |
| CAS (representative) | 68439-49-6 |
| Base alcohol | Cetearyl alcohol (C16–C18 blend) |
| Average EO moles | 20 |
| HLB (approx.) | ~15–16 |
| Primary function | O/W emulsifier, thickener, mild surfactant |
Ceteareth-20 is among the most common emulsifiers in global cosmetic formulations. It blends oil and water phases in facial moisturizers, body lotions, sunscreens, hair conditioners, cleansers, and depilatory creams. When paired with cetearyl alcohol in the oil phase, it creates a self-bodying emulsifier system that builds viscosity on cooling and delivers long-term emulsion stability.
Ceteth-2 vs Ceteth-20 vs Ceteareth-20
| Grade | EO moles | HLB | Best for |
|---|---|---|---|
| Ceteth-2 | 2 | Low (~5–6) | Co-emulsifier, oil-phase solubilizer, W/O support |
| Ceteth-20 | 20 | High (~15) | O/W emulsifier from pure cetyl alcohol feedstock |
| Ceteareth-20 | 20 | High (~15–16) | Primary O/W emulsifier; pairs with cetearyl alcohol |
The practical difference between Ceteth-20 and Ceteareth-20 is the alcohol feedstock: cetyl-only versus cetyl/stearyl blend. Ceteareth-20 often provides slightly richer body in lotions because the stearyl component contributes to wax crystal network formation during cooling. Ceteth-2 is not interchangeable with Ceteth-20 — they bracket opposite ends of the HLB scale and are used together in emulsifier pairs.
Formulation example: O/W body lotion
| Component | % w/w | Function |
|---|---|---|
| Cetearyl alcohol | 2.5 | Co-emulsifier, viscosity builder |
| Ceteareth-20 | 1.5 | Primary O/W emulsifier |
| Caprylic/capric triglyceride | 8.0 | Emollient oil phase |
| Glycerin | 5.0 | Humectant |
| Preservative, fragrance, water | q.s. | — |
Heat oil and water phases to 75–80°C, combine under homogenization, and cool with stirring below 40°C. Adjust cetearyl alcohol level for target viscosity. See the HLB scale guide to verify emulsifier balance against your oil phase.
Applications in personal care
- Skin care: Facial creams, body lotions, sunscreens, anti-aging treatments
- Hair care: Conditioners, hair dyes, permanent-wave lotions
- Cleansing: Facial cleansers, body washes, makeup removers
- Specialty: Depilatory creams, exfoliant scrubs, baby care products
Safety and regulatory profile
CIR safety assessments cover Ceteth-1 through Ceteth-45. Ethoxylated ingredients may contain trace 1,4-dioxane if purification is inadequate — cosmetic suppliers should provide dioxane specifications. Ceteth and Ceteareth grades are listed in EU CosIng and are widely used in rinse-off and leave-on products globally.
Venus supply
Venus Ethoxyethers lists Ceteareth-20, Laureth, Oleth, and Glycereth grades on the co-surfactants & emulsifiers page. For broader INCI context, see the cosmetic emulsifiers hub and personal care surfactants guide.
Request samples, TDS, and INCI documentation via contact Venus Ethoxyethers.
Building robust systems with Ceteth and Ceteareth
Ceteth and Ceteareth grades are most effective when used as part of an HLB-balanced pair rather than isolated ingredients. Low-EO materials such as Ceteth-2 support lipophilic compatibility, while high-EO materials like Ceteth-20 and Ceteareth-20 stabilize oil droplets in water. This pairing strategy gives formulators better stability control across variable oil loads and active packages.
In commercial personal care manufacturing, Ceteareth-20 is often preferred as the primary high-HLB anchor because cetearyl feedstock contributes richer body in creams and lotions. Ceteth-20 remains valuable where cetyl-focused sensory and process profiles are preferred.
Selection chart for real-world product goals
| Product goal | Main grade | Support grade | Why this combination works |
|---|---|---|---|
| Classic O/W body lotion | CETEARETH-20 | Cetearyl alcohol / Ceteth-2 | Strong interface stabilization with rich body |
| Lighter fluid emulsion | CETETH-20 | Low wax structurant | Hydrophilic emulsification with lighter finish |
| Oil-rich cream stabilization | CETEARETH-20 | CETETH-2 | High+low HLB pairing improves robustness |
| Hair treatment base | CETEARETH-20 | Cationic conditioner system | Stable emulsion with conditioning package compatibility |
Worked formulation example: moisturizer with balanced HLB pair
| Phase | Material | % w/w | Function |
|---|---|---|---|
| A | Emollient oil blend | 11.0 | Oil phase |
| A | CETEARETH-20 | 1.8 | Primary O/W emulsifier |
| A | CETETH-2 | 0.6 | Lipophilic co-emulsifier support |
| A | Cetearyl alcohol | 1.8 | Body and lamellar structure |
| B | Water + glycerin | q.s.; 4.0 glycerin | Aqueous phase |
| C | Preservative and heat-sensitive actives | as required | Performance package |
Heat phases to 75–78°C, emulsify under controlled shear, then cool with sweep mixing. The Ceteth-2 fraction can improve interfacial flexibility and help reduce instability in higher-oil formulas. Bench optimization should include centrifugal and freeze-thaw stress.
Hair-care perspective: conditioner and color systems
In conditioners and treatment creams, Ceteareth/Ceteth systems support dispersion of fatty alcohol networks and conditioning agents. They can also improve uniformity in hair-color or treatment products that contain complex solvent and oil blends. Final performance depends on interactions with cationic polymers and quats, so compatibility screening is recommended.
When targeting richer post-rinse feel, formulators often maintain Ceteareth-20 while increasing structural alcohols. For lighter rinse profile, lower wax loading and introduce selected nonionic partners from Laureth/Oleth grades.
Regulatory and quality implementation notes
As ethoxylated ingredients, Ceteth and Ceteareth products should be sourced with impurity control and transparent technical documentation. Qualification packs typically include TDS, COA, INCI confirmation, and declarations on process-related residuals required by customer standards.
For global rollouts, harmonize INCI terminology and concentration ranges across technical files, artwork, and customer communications. This avoids costly relabeling or registration corrections after pilot or first commercial lots.
Troubleshooting matrix for production teams
| Issue observed | Likely cause | Practical correction |
|---|---|---|
| Cream separation in heat cycle | Insufficient emulsifier balance | Increase high-HLB component or optimize homogenization |
| Excessive drag during rub-in | High wax structuring load | Reduce fatty alcohol or add sensory modifier |
| Watery final viscosity | Weak lamellar network | Adjust cetearyl alcohol and cooling profile |
| Cloudy low-viscosity product | Fragrance/oil solubilization mismatch | Add high-HLB solubilizer support |
Production qualification recommendations
- Pilot homogenization window: define minimum and maximum shear limits before scale-up.
- Thermal hold control: verify hold time at emulsification temperature for repeatability.
- Aging protocol: include 5°C, ambient, and 45°C checkpoints with visual and rheology data.
- Documentation readiness: complete INCI and quality declarations before customer audit cycles.
These operational controls are especially useful when a business runs multiple lotion SKUs from one base architecture and needs high batch-to-batch reproducibility.
Venus Ethoxyethers cross-links
To complete your emulsifier selection map, see cosmetic emulsifiers hub, PEG stearate guide, HLB scale guide, and co-surfactants and emulsifiers. Technical and commercial teams can request support through Venus Ethoxyethers.