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Moumoujus

CETEARETH-9.

Valuable CAS 68439-49-6 / SURFACTANT - CLEANSING, SURFACTANT - EMULSIFYING

Ceteareth-9 is a versatile non-ionic surfactant and emulsifying agent used to integrate oil and water phases into a cohesive, uniform texture. It is a workhorse ingredient in precision skincare, essential for maintaining the structural integrity and shelf-stability of complex topical formulations.

Summary

surfactant emulsifying cleansing stabilizing

Science

Mechanism of Action

As an amphiphilic molecule, Ceteareth-9 contains both a lipophilic fatty alcohol tail and a hydrophilic polyethylene glycol (PEG) head. It functions by reducing interfacial tension and organizing into micellar structures around oil droplets, which prevents coalescence and ensures a homogenous distribution of ingredients throughout the formula.

Research

Clinical Evidence

High confidence
Effective range 1–10%
Optimal

5%

Key findings

  1. 01 Clinical patch testing over 4 and 21 days at 1.5% concentration demonstrated that Ceteareth-9 is a non-sensitizer with minimal irritation potential.
  2. 02 Safety trials involving related ethoxylates at 10% concentration confirmed only negligible irritation following acute dermal exposure.

Transparency

Dusting Analysis

Not commonly dusted
Min. effective
0.5%
Red flag below
0.1%

As a functional emulsifier rather than a primary active, Ceteareth-9 is rarely 'dusted.' It is typically included at the specific concentration required to stabilize the specific ratio of oils in a formula.

The Formula

Formulation

Solubility
Oil
Optimal pH 5 – 9
0 7 14

Stability

Exhibits excellent stability across a broad pH spectrum and is resistant to oxidation. It remains compatible with most ionic and non-ionic cosmetic components.

Synergies

  • Fatty alcohols
  • Non-ionic surfactants
  • Lipophilic actives

Conflicts

  • Strong oxidizing agents
  • Phenolic preservatives (potential efficacy reduction)

Safety

Safety Profile

CIR Status
Safe as used
Max tested
10%
Pregnancy
Safe
Sensitization risk Low

While safe for general use, formulations containing Ceteareth-9 should not be applied to severely damaged or burned skin to avoid potential PEG-related systemic toxicity.

Your Skin

Skin Compatibility

Yes Normal
Yes Dry
Yes Oily
Yes Sensitive
Irritancy Low
Comedogenicity Low

Our Assessment

Verdict

Valuable

A highly reliable and skin-safe emulsifier that ensures product consistency and effective delivery of lipid-based ingredients.

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