Ingredient review

C11-15 Pareth-12

INCI: C11-15 SEC-PARETH-12

A gentle synthetic cleanser that helps remove dirt and oil, but may be slightly drying for very sensitive skin.

beautyskincaresurfactant

In plain English

This ingredient is a man-made cleanser that helps water mix with oil and dirt so they can be rinsed away. It's often used in face washes and shampoos to create a light foam and leave skin feeling clean without being too harsh.

Review score

Safety, usefulness, and evidence

3.5Good
3.5/ 5

Potentially useful with some tradeoffs

The evidence base is useful, but some claims depend heavily on the formula.

Main practical flags: irritation is moderate; clogging risk is low.

Source
synthetic
Evidence
moderate
Irritation
moderate
Clogging risk
low
How reviews are scored

Quick decision guide

Useful, but context matters

C11-15 Pareth-12 can be useful, but watch for some irritation potential.

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 C11-15 Pareth-12.
  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

moderate

Can bother some users, especially with frequent use, damaged skin, or strong companion ingredients.

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

A synthetic surfactant made from a blend of C11-15 secondary alcohols reacted with ethylene oxide. It belongs to the alcohol ethoxylate family, commonly used in personal care products for their cleansing and emulsifying properties.

How it works

It reduces the surface tension between water and oil, allowing them to blend. This helps lift dirt, sebum, and makeup from the skin so they can be washed away with water. It also helps stabilize oil-in-water emulsions in creams and lotions.

Pros

Gentle cleansing

Removes excess oil and impurities without stripping the skin's natural moisture barrier as much as harsher sulfates.

Good foam

Produces a light, satisfying lather that makes cleansing feel effective and pleasant.

Cons and cautions

Potential dryness

May cause slight tightness or dryness for those with very dry or sensitive skin, especially with frequent use.

Synthetic origin

Derived from petrochemicals, which may be a concern for those preferring natural or biodegradable ingredients.

Best for

  • People with normal to oily skin looking for a gentle cleanser
  • Anyone who wants a mild foaming wash without sulfates

Use caution if

  • Those with very dry or compromised skin barriers
  • Individuals seeking 100% natural or plant-based ingredients

Usage tips

Use in rinse-off products like cleansers and shampoos rather than leave-on formulas to minimize potential irritation.
Follow with a moisturizer if you notice any dryness after cleansing.

Safety summary

C11-15 Pareth-12 is considered safe for use in rinse-off cosmetics at typical concentrations. It has low acute toxicity and is not a known sensitizer, though it may cause mild irritation in very sensitive individuals.

Research notes

Safety assessments by the Cosmetic Ingredient Review (CIR) panel have concluded that alcohol ethoxylates are safe when formulated to be non-irritating. Studies show they are readily biodegradable and have low potential for bioaccumulation.

Common label clues

Typical concentration
0.5% to 5%
Regulatory status
Approved for use in cosmetics in the EU, US, and many other regions. No specific restrictions beyond general cosmetic safety requirements.
Common uses
Cleansers, Shampoos, Body washes, Facial lotions
Environmental note
Alcohol ethoxylates like this one are generally biodegradable, but their production relies on non-renewable petrochemicals.

Good to know

  • This ingredient is often used as a gentler alternative to sodium lauryl sulfate (SLS).
  • It is considered biodegradable under standard wastewater treatment conditions.

Common questions

What is C11-15 Pareth-12 in beauty products?

This ingredient is a man-made cleanser that helps water mix with oil and dirt so they can be rinsed away. It's often used in face washes and shampoos to create a light foam and leave skin feeling clean without being too harsh.

What does C11-15 Pareth-12 do in a beauty product?

It reduces the surface tension between water and oil, allowing them to blend. This helps lift dirt, sebum, and makeup from the skin so they can be washed away with water. It also helps stabilize oil-in-water emulsions in creams and lotions.

Is C11-15 Pareth-12 safe for most people?

C11-15 Pareth-12 is considered safe for use in rinse-off cosmetics at typical concentrations. It has low acute toxicity and is not a known sensitizer, though it may cause mild irritation in very sensitive individuals.

Who should be careful with C11-15 Pareth-12?

Those with very dry or compromised skin barriers Individuals seeking 100% natural or plant-based ingredients

Research sources

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.