Steareth-21

What is Steareth-21?

Steareth-21 is a synthetic non-ionic surfactant produced by ethoxylating stearyl alcohol, a long-chain fatty alcohol sourced from plant or animal fats, with 21 molecules of ethylene oxide. This creates a hydrophilic molecule with a hydrophobic tail, ideal for cosmetic applications in emulsions like creams, lotions, shampoos, and cleansers. It functions by reducing surface tension at interfaces, stabilizing oil-in-water mixtures through micelle formation that encapsulates oils. This emulsifying action ensures uniform product texture and prevents phase separation. In cleansing products, it lifts dirt and sebum via micelles for rinse-off efficacy. As a solubilizer, it disperses water-insoluble actives and scents into clear aqueous bases, supporting toners and sprays. Its balanced HLB value around 15.5 promotes effective blending in personal care formulations without compromising stability.

Comedogenic Rating 0/5 Low risk of clogging pores
EWG Safety Rating 1-3 View on EWG →
PubChem View on PubChem →

Roles in Formulation

This ingredient serves the following purposes in cosmetic formulations:

Surfactant
Lowers surface tension to enable cleansing, emulsifying, and foaming; central to shampoos, body washes, and many emulsions and micellar systems.
Cleansing agent
Removes dirt, oil, and impurities by lowering surface tension and forming micelles, enabling soils to be lifted and rinsed away from skin, hair, or teeth.
Emulsifying agent
Enables stable mixing of oil and water phases by forming an interfacial film, helping create lotions, creams, and cleansers with consistent texture.
Solubilizing agent
Helps incorporate oils and fragrance into water-based formulas by forming micro-solutions, enabling clear sprays, toners, and micellar products.

Benefits

Supports creation of smooth, stable emulsions in creams and lotions.

Provides gentle cleansing by trapping oils and impurities for easy removal.

Enhances solubility of fragrances and oils in water-based products.

Who It's For

A quick guide for who this ingredient may suit (and who should be cautious).

Who May Benefit Who Should Avoid
Users of daily cleansers and shampoos seeking mild surfactant action.
Those with rare sensitivity to ethoxylated compounds.
Individuals formulating or using emulsified moisturizers.
People opting for completely natural or PEG-free products.
People preferring non-comedogenic ingredients in routines.
Individuals experiencing irritation from similar surfactants.

Safety Notes

  • Assessed as low hazard in cosmetic concentrations by safety reviews.
  • Non-comedogenic profile suits acne-prone skin concerns.

Frequently Asked Questions about Steareth-21

What is Steareth-21 used for in cosmetics?

It serves as a surfactant, emulsifier, cleanser, and solubilizer in products like lotions, shampoos, and toners to mix phases and remove impurities.

Is Steareth-21 safe for sensitive skin?

Safety assessments indicate low irritation risk at typical use levels, though patch testing is advisable for sensitivities.

Does Steareth-21 clog pores?

It has a non-comedogenic rating, making it unlikely to contribute to pore blockages.