Ingredient review

Beheneth-20

INCI: Beheneth-20

A gentle, non-drying emulsifier that helps create stable, creamy formulas without stripping the skin.

beautyskincaresurfactant

In plain English

Beheneth-20 is a mild ingredient that helps oil and water mix together in products like lotions and cleansers. It comes from behenic acid, which is found in natural oils like rapeseed oil, but it is processed to make it work better in formulas. Because it is gentle, it cleans without leaving your skin feeling tight or dry.

Quick decision guide

Useful, but context matters

Beheneth-20 is generally a lower-concern ingredient when the full formula suits your skin.

Plain-English read

Treat this as a practical screening step before you compare products that contain this ingredient.

  1. Step 1Start with the score, then check the irritation and clogging risk before judging Beheneth-20.
  2. Step 2Use the "Best for" and "Use caution if" sections to match the ingredient to your skin, not just to a marketing claim.
  3. Step 3If a product stings, breaks you out, or worsens irritation, judge the finished formula and stop using it even if the ingredient scores well.

Score terms in plain English

Irritation risk

low

Less likely to sting, burn, or bother most users, though sensitive skin can still react.

Clogging risk

low

Less likely to feel heavy or contribute to clogged pores for most skin types.

Evidence level

moderate

There is useful support, but formula details and claim strength still matter.

What it is

Beheneth-20 is a semi-synthetic emulsifier made by attaching 20 ethylene oxide units to behenyl alcohol (a fatty alcohol derived from plant oils). It belongs to the ethoxylated fatty alcohol family and is valued for its mildness and ability to stabilize oil-in-water emulsions.

How it works

In a cosmetic product, Beheneth-20 sits at the boundary between oil and water droplets, reducing surface tension so they blend into a smooth, stable cream or lotion. It also has mild cleansing properties, helping to lift dirt and oil from the skin without being harsh or stripping.

Pros

Gentle on skin

Unlike harsher sulfates, Beheneth-20 cleans without stripping natural oils, making it ideal for dry or sensitive skin types.

Stable emulsions

It helps lotions and creams stay smooth and consistent over time, so you don't get watery separation in the bottle.

Cons and cautions

Potential trace contaminant

During manufacturing, ethoxylation can create tiny amounts of 1,4-dioxane, which some consumers prefer to avoid. Reputable brands purify to keep levels very low.

Not for PEG-free routines

If you avoid polyethylene glycol (PEG) compounds for personal reasons, Beheneth-20 is not a fit.

Best for

  • People with dry or sensitive skin looking for gentle cleansers
  • Anyone who prefers mild, non-stripping formulas

Use caution if

  • Those who strictly avoid PEGs or ethoxylated ingredients

Usage tips

Use in oil-in-water emulsions at 1–5% for best stability
Combine with a co-emulsifier like cetearyl alcohol for thicker textures
Store products in a cool, dry place to maintain emulsion integrity

Safety summary

Beheneth-20 is considered safe for use in cosmetics at typical concentrations. The main concern is trace 1,4-dioxane, but reputable manufacturers purify to levels well below safety limits. It is non-irritating and non-comedogenic for most people.

Research notes

Studies on ethoxylated fatty alcohols indicate low acute toxicity and skin irritation. The CIR panel concluded these ingredients are safe when formulated to minimize 1,4-dioxane. No significant human or environmental risks have been identified at cosmetic use levels.

Common label clues

Typical concentration
1–5%
Regulatory status
Approved for use in cosmetics in the EU, US, and many other regions. The Cosmetic Ingredient Review (CIR) panel has reviewed ethoxylated fatty alcohols and found them safe when formulated to minimize 1,4-dioxane.
Common uses
Cleansers, Moisturizers, Conditioners, Hair products
Environmental note
Beheneth-20 is derived from plant oils and is biodegradable, but the ethoxylation process uses ethylene oxide, which is energy-intensive. Overall environmental impact is moderate.

Good to know

  • Beheneth-20 is often used in 'no-poo' or low-poo hair cleansers because it is mild
  • It is considered biodegradable and generally safe for aquatic life at typical use levels

Common questions

What is Beheneth-20 in beauty products?

Beheneth-20 is a mild ingredient that helps oil and water mix together in products like lotions and cleansers. It comes from behenic acid, which is found in natural oils like rapeseed oil, but it is processed to make it work better in formulas. Because it is gentle, it cleans without leaving your skin feeling tight or dry.

What does Beheneth-20 do in a beauty product?

In a cosmetic product, Beheneth-20 sits at the boundary between oil and water droplets, reducing surface tension so they blend into a smooth, stable cream or lotion. It also has mild cleansing properties, helping to lift dirt and oil from the skin without being harsh or stripping.

Is Beheneth-20 safe for most people?

Beheneth-20 is considered safe for use in cosmetics at typical concentrations. The main concern is trace 1,4-dioxane, but reputable manufacturers purify to levels well below safety limits. It is non-irritating and non-comedogenic for most people.

Who should be careful with Beheneth-20?

Those who strictly avoid PEGs or ethoxylated ingredients

Research sources

Cosmetic Ingredient Review (CIR) – Safety Assessment of Ethoxylated Fatty AlcoholsOpenEuropean Chemicals Agency (ECHA) – Beheneth-20 InformationOpenPubChem – Beheneth-20 Compound SummaryOpen

Ingredient reviews are educational and are not medical advice. Patch test new products and ask a licensed clinician about persistent irritation, allergies, pregnancy-specific questions, or diagnosed skin conditions.