Ingredient review
C11-15 Pareth-7 Carboxylic Acid
INCI: C11-15 PARETH-7 CARBOXYLIC ACID
A gentle, semi-synthetic surfactant that helps cleanse without stripping the skin's natural moisture barrier.
In plain English
This ingredient is a mild soap-like molecule that helps water mix with oil and dirt so they can be rinsed away. It's made from a blend of fatty alcohols (from plant or synthetic sources) and ethylene oxide, then modified to be less harsh than traditional soaps. In your cleanser, it creates a light foam and leaves skin feeling clean but not tight or dry.
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
- semi synthetic
- Evidence
- moderate
- Irritation
- low
- Clogging risk
- low
Quick decision guide
Useful, but context matters
C11-15 Pareth-7 Carboxylic Acid 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-7 Carboxylic Acid.
- 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 carboxylic acid surfactant from the alkyl ether carboxylate family, produced by reacting C11-15 fatty alcohols with ethylene oxide and then oxidizing the terminal alcohol group to a carboxylic acid. It is a semi-synthetic ingredient that combines the mildness of nonionic surfactants with the cleansing power of anionic ones.
How it works
In water, the molecule arranges itself so that the fatty tail grabs oil and dirt while the carboxylic acid head pulls them into the water. This allows the rinse-off process to remove impurities without aggressively stripping the skin's natural oils. Its mild pH profile makes it less irritating than many traditional sulfates.
Pros
Mild on skin
Its carboxylic acid structure makes it less irritating than many common surfactants like sodium lauryl sulfate, so it's suitable for daily use without over-stripping.
Good foam quality
It produces a stable, creamy lather that feels luxurious on the skin, making it a popular choice in high-end cleansers and body washes.
Cons and cautions
Potential ethoxylation concerns
As an ethoxylated ingredient, trace amounts of 1,4-dioxane (a potential contaminant) can form during manufacturing, though reputable brands purify to safe levels.
Not fully natural
Despite being derived partly from natural fatty alcohols, the ethoxylation process is synthetic, which may not appeal to those seeking 100% natural formulations.
Best for
- People with normal to combination skin looking for a gentle daily cleanser
- Those who prefer sulfate-free or milder cleansing options
Use caution if
- Individuals with known allergies to ethoxylated ingredients (rare) should patch test first
Usage tips
Safety summary
C11-15 Pareth-7 Carboxylic Acid is considered safe for use in cosmetics at typical concentrations. The main safety consideration is the potential for 1,4-dioxane contamination during manufacturing, but reputable suppliers control this to trace levels. It has low irritation and comedogenic potential, making it suitable for most skin types.
Research notes
Studies on alkyl ether carboxylates show they are mild to the skin and eyes compared to traditional anionic surfactants. The Cosmetic Ingredient Review (CIR) panel has reviewed similar ethoxylated surfactants and found them safe when formulated properly. No specific long-term human studies are available for this exact compound, but the class is well-established.
Common label clues
- Typical concentration
- 1–10% in rinse-off products; lower in leave-on formulas
- Regulatory status
- Approved for use in cosmetics by the FDA (as part of the generally recognized as safe framework) and listed in the EU CosIng database. Manufacturers are expected to keep 1,4-dioxane levels below 10 ppm per industry guidelines.
- Common uses
- Facial cleansers, Body washes, Shampoos, Makeup removers
- Environmental note
- Alkyl ether carboxylates are generally considered more biodegradable than many traditional surfactants, though the ethoxylation process has some environmental footprint.
Good to know
- This ingredient is often listed near the middle or end of an ingredient list because it's used at moderate concentrations.
- It is considered biodegradable and has a favorable environmental profile compared to some older surfactants.
Common questions
What is C11-15 Pareth-7 Carboxylic Acid in beauty products?
This ingredient is a mild soap-like molecule that helps water mix with oil and dirt so they can be rinsed away. It's made from a blend of fatty alcohols (from plant or synthetic sources) and ethylene oxide, then modified to be less harsh than traditional soaps. In your cleanser, it creates a light foam and leaves skin feeling clean but not tight or dry.
What does C11-15 Pareth-7 Carboxylic Acid do in a beauty product?
In water, the molecule arranges itself so that the fatty tail grabs oil and dirt while the carboxylic acid head pulls them into the water. This allows the rinse-off process to remove impurities without aggressively stripping the skin's natural oils. Its mild pH profile makes it less irritating than many traditional sulfates.
Is C11-15 Pareth-7 Carboxylic Acid safe for most people?
C11-15 Pareth-7 Carboxylic Acid is considered safe for use in cosmetics at typical concentrations. The main safety consideration is the potential for 1,4-dioxane contamination during manufacturing, but reputable suppliers control this to trace levels. It has low irritation and comedogenic potential, making it suitable for most skin types.
Who should be careful with C11-15 Pareth-7 Carboxylic Acid?
Individuals with known allergies to ethoxylated ingredients (rare) should patch test first
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.