Ingredient review
C11-15 Pareth-15
INCI: C11-15 PARETH-15
A mild synthetic surfactant that helps cleansers foam and rinse cleanly without stripping the skin.
In plain English
C11-15 Pareth-15 is a man-made ingredient that helps water and oil mix together in products like face washes and shampoos. It creates a gentle foam and helps rinse away dirt and makeup without leaving a greasy film. Because it's made from fatty alcohols and ethylene oxide, it's considered a mild surfactant that is less likely to irritate than harsher soaps.
Review score
Safety, usefulness, and evidence
Potentially useful with some tradeoffs
The evidence base is useful, but some claims depend heavily on the formula.
Risk flags are low for most users, though the finished product can still irritate.
- Source
- synthetic
- Evidence
- moderate
- Irritation
- low
- Clogging risk
- low
Quick decision guide
Useful, but context matters
C11-15 Pareth-15 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.
- Step 1Start with the score, then check the irritation and clogging risk before judging C11-15 Pareth-15.
- Step 2Use the "Best for" and "Use caution if" sections to match the ingredient to your skin, not just to a marketing claim.
- 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
lowLess likely to sting, burn, or bother most users, though sensitive skin can still react.
Clogging risk
lowLess likely to feel heavy or contribute to clogged pores for most skin types.
Evidence level
moderateThere is useful support, but formula details and claim strength still matter.
What it is
A synthetic non-ionic surfactant derived from a blend of C11-15 fatty alcohols and ethylene oxide. It belongs to the alcohol ethoxylate family and is commonly used as an emulsifier and cleansing agent.
How it works
It reduces the surface tension between oil and water, allowing them to mix. In a cleanser, it helps lift dirt, oil, and makeup from the skin so they can be rinsed away. Its mild nature means it cleans without stripping the skin's natural moisture barrier.
Pros
Mild on skin
C11-15 Pareth-15 is considered a gentle surfactant that cleans effectively without causing significant irritation or dryness for most skin types.
Good foam quality
It produces a rich, stable lather that many people enjoy in cleansers and shampoos, making the cleansing experience pleasant.
Cons and cautions
Synthetic origin
It is manufactured from petrochemicals, which may not appeal to those seeking natural or eco-friendly ingredients.
Potential for slight dryness
While mild, frequent use in high concentrations may still be slightly drying for very dry or compromised skin barriers.
Best for
- People with normal to combination skin
- Those looking for a gentle, non-stripping cleanser
Use caution if
- Individuals with known sensitivity to ethoxylated ingredients
- Those seeking 100% natural or plant-based formulations
Usage tips
Safety summary
C11-15 Pareth-15 is considered safe for use in cosmetics at typical concentrations. It is a mild surfactant with low irritation and comedogenic potential. As with all ethoxylated ingredients, purity standards are important to avoid trace contaminants.
Research notes
Alcohol ethoxylates like C11-15 Pareth-15 have been reviewed by the Cosmetic Ingredient Review (CIR) panel and found safe for use in rinse-off and leave-on products when formulated properly. Studies indicate low skin irritation and sensitization potential.
Common label clues
- Typical concentration
- 1–5% in rinse-off products; lower in leave-on formulations
- Regulatory status
- Approved for use in cosmetics in the US (FDA) and EU (CosIng) with no known restrictions at typical concentrations.
- Common uses
- Cleansers, Shampoos, Body washes, Facial cleansers
- Environmental note
- As a synthetic ethoxylate, it may have moderate biodegradability. Some ethoxylates can form byproducts like 1,4-dioxane during manufacturing, but reputable suppliers control for purity.
Good to know
- C11-15 Pareth-15 is part of a larger family of alcohol ethoxylates, which are widely used in cosmetics for their mild cleansing properties.
- It is often found in sulfate-free formulations as a gentler alternative to sodium lauryl sulfate.
Common questions
What is C11-15 Pareth-15 in beauty products?
C11-15 Pareth-15 is a man-made ingredient that helps water and oil mix together in products like face washes and shampoos. It creates a gentle foam and helps rinse away dirt and makeup without leaving a greasy film. Because it's made from fatty alcohols and ethylene oxide, it's considered a mild surfactant that is less likely to irritate than harsher soaps.
What does C11-15 Pareth-15 do in a beauty product?
It reduces the surface tension between oil and water, allowing them to mix. In a cleanser, it helps lift dirt, oil, and makeup from the skin so they can be rinsed away. Its mild nature means it cleans without stripping the skin's natural moisture barrier.
Is C11-15 Pareth-15 safe for most people?
C11-15 Pareth-15 is considered safe for use in cosmetics at typical concentrations. It is a mild surfactant with low irritation and comedogenic potential. As with all ethoxylated ingredients, purity standards are important to avoid trace contaminants.
Who should be careful with C11-15 Pareth-15?
Individuals with known sensitivity to ethoxylated ingredients Those seeking 100% natural or plant-based formulations
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.