Ingredient review

Beheneth-5

INCI: BEHENETH-5

Beheneth-5 is a gentle synthetic emulsifier that helps oil and water mix, making creams and lotions feel smooth without heavy irritation.

beautyskincaresurfactant

In plain English

Beheneth-5 is a man-made ingredient that helps water and oil stay blended in your skincare products. It's part of a family of emulsifiers that are known for being very mild on the skin. Think of it as a friendly peacekeeper that keeps your lotion from separating into watery and oily layers. It also helps your cleansers foam gently and leaves hair feeling soft without stripping natural oils.

Quick decision guide

Useful, but context matters

Beheneth-5 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-5.
  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-5 is a synthetic emulsifier made by attaching 5 ethylene oxide units to behenyl alcohol (a fatty alcohol derived from oils like rapeseed). It belongs to the ethoxylated fatty alcohol family and is used to create stable, smooth emulsions.

How it works

In a cosmetic formula, Beheneth-5 sits at the boundary between oil and water droplets, reducing surface tension so they mix into a uniform cream or lotion. It also lowers the surface tension of water, which helps cleansers spread and foam more effectively. Because it's non-ionic (no electrical charge), it works well with other ingredients and is less likely to irritate sensitive skin.

Pros

Very low irritation risk

Beheneth-5 is considered one of the gentlest emulsifiers, making it a good choice for sensitive skin formulas and baby products.

Versatile in formulas

It works well in both creams and cleansers, helping to create a smooth, non-greasy feel that many people prefer.

Cons and cautions

Ethoxylation concerns

The manufacturing process can create trace amounts of 1,4-dioxane, a potential carcinogen. However, reputable brands purify their ingredients to keep levels well below safety limits.

Not fully biodegradable

Like many synthetic emulsifiers, Beheneth-5 may persist in the environment longer than natural alternatives, which is a consideration for eco-conscious consumers.

Best for

  • People with normal to dry skin looking for stable, non-irritating moisturizers
  • Anyone wanting gentle cleansers or conditioners that don't strip the skin

Use caution if

  • Those who strictly avoid all ethoxylated ingredients due to 1,4-dioxane concerns (though levels are typically very low in finished products)

Usage tips

Look for products that list Beheneth-5 near the middle of the ingredient list to ensure it's at a functional but not excessive level.
If you're concerned about 1,4-dioxane, choose brands that test their finished products for purity or use certified organic alternatives.

Safety summary

Beheneth-5 is considered safe for use in cosmetics at typical concentrations. The main concern is trace 1,4-dioxane from ethoxylation, but regulatory bodies set strict limits, and most products contain negligible amounts. It is non-irritating and non-sensitizing for the vast majority of users.

Research notes

Safety assessments by the Cosmetic Ingredient Review (CIR) and European Chemicals Agency (ECHA) support the use of ethoxylated fatty alcohols like Beheneth-5 in rinse-off and leave-on products. Studies show low acute toxicity and no significant skin irritation or sensitization. Research on environmental impact is limited but indicates moderate biodegradability.

Common label clues

Typical concentration
Usually 0.5–5% in leave-on products; up to 10% in rinse-off formulas
Regulatory status
Approved for use in cosmetics in the US (FDA), EU (CosIng), and many other regions. The Cosmetic Ingredient Review (CIR) panel has deemed ethoxylated fatty alcohols safe when formulated to minimize 1,4-dioxane.
Common uses
Moisturizers, Conditioners, Cleansers
Environmental note
Beheneth-5 is synthetic and not readily biodegradable in all environments. Some manufacturers are moving toward greener alternatives like plant-based emulsifiers.

Good to know

  • Beheneth-5 is often used alongside other emulsifiers like cetearyl alcohol to create a stable, creamy texture.
  • The number '5' refers to the average number of ethylene oxide units, which affects how water-loving or oil-loving the molecule is.

Common questions

What is Beheneth-5 in beauty products?

Beheneth-5 is a man-made ingredient that helps water and oil stay blended in your skincare products. It's part of a family of emulsifiers that are known for being very mild on the skin. Think of it as a friendly peacekeeper that keeps your lotion from separating into watery and oily layers. It also helps your cleansers foam gently and leaves hair feeling soft without stripping natural oils.

What does Beheneth-5 do in a beauty product?

In a cosmetic formula, Beheneth-5 sits at the boundary between oil and water droplets, reducing surface tension so they mix into a uniform cream or lotion. It also lowers the surface tension of water, which helps cleansers spread and foam more effectively. Because it's non-ionic (no electrical charge), it works well with other ingredients and is less likely to irritate sensitive skin.

Is Beheneth-5 safe for most people?

Beheneth-5 is considered safe for use in cosmetics at typical concentrations. The main concern is trace 1,4-dioxane from ethoxylation, but regulatory bodies set strict limits, and most products contain negligible amounts. It is non-irritating and non-sensitizing for the vast majority of users.

Who should be careful with Beheneth-5?

Those who strictly avoid all ethoxylated ingredients due to 1,4-dioxane concerns (though levels are typically very low in finished products)

Research sources

Cosmetic Ingredient Review (CIR) – Safety Assessment of Ethoxylated Fatty AlcoholsOpenEuropean Chemicals Agency (ECHA) – Beheneth-5 InformationOpenPubMed – Skin irritation potential of ethoxylated surfactantsOpen

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.