Ingredient review
C11-15 Pareth-30
INCI: C11-15 PARETH-30
A gentle synthetic emulsifier that helps mix oil and water, but may cause mild irritation for very sensitive skin.
In plain English
C11-15 Pareth-30 is a man-made ingredient that helps water and oil stay blended in products like cleansers and lotions. It belongs to a group called ethoxylated alcohols, which are made by adding ethylene oxide to fatty alcohols. This process creates a mild surfactant that can clean without stripping too much moisture, though it may still be slightly drying for some skin types.
Review score
Safety, usefulness, and evidence
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
Quick decision guide
Useful, but context matters
C11-15 Pareth-30 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.
- Step 1Start with the score, then check the irritation and clogging risk before judging C11-15 Pareth-30.
- 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
moderateCan bother some users, especially with frequent use, damaged skin, or strong companion ingredients.
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 surfactant and emulsifier derived from fatty alcohols (C11-15) that have been reacted with 30 units of ethylene oxide. It is part of the ethoxylated alcohol family, commonly used in personal care for its ability to reduce surface tension and stabilize mixtures.
How it works
It works by lowering the surface tension between oil and water, allowing them to mix into a stable emulsion. In cleansers, it helps lift dirt and oil from the skin so they can be rinsed away. The '30' in its name indicates a high degree of ethoxylation, which makes it milder and more water-soluble than shorter-chain versions.
Pros
Mild cleansing
Compared to harsher sulfates, C11-15 Pareth-30 provides effective cleansing with less stripping, making it suitable for daily use.
Texture enhancer
It helps create smooth, creamy formulas that feel pleasant on the skin and rinse off easily.
Cons and cautions
Potential irritation
For those with very sensitive skin, even mild ethoxylated surfactants can cause redness or tightness, especially in leave-on products.
Processing concerns
The ethoxylation process can form trace amounts of 1,4-dioxane, a potential contaminant, though reputable manufacturers purify to safe levels.
Best for
- People with normal to oily skin looking for a gentle cleanser
- Those who prefer synthetic surfactants over sulfate-based ones
Use caution if
- Individuals with very sensitive or compromised skin barriers who may react to ethoxylated ingredients
Usage tips
Safety summary
C11-15 Pareth-30 is considered safe for use in cosmetics at typical concentrations. The main concern is potential skin irritation for sensitive individuals and trace impurities from manufacturing, which are regulated. Overall, it is a well-tolerated synthetic emulsifier.
Research notes
Studies on ethoxylated alcohols indicate low acute toxicity and moderate skin irritation potential. The Cosmetic Ingredient Review (CIR) panel has reviewed similar ingredients and found them safe when formulated to minimize impurities. More specific data on C11-15 Pareth-30 is limited, but it is grouped with related compounds.
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 and EU CosIng database. Manufacturers are expected to keep 1,4-dioxane levels below 10 ppm per industry guidelines.
- Common uses
- Cleansers, Shampoos, Body washes, Emulsions
- Environmental note
- Ethoxylated surfactants can be slow to biodegrade in aquatic environments, though modern formulations often use lower concentrations.
Good to know
- The '30' refers to the number of ethylene oxide units, which influences water solubility and mildness.
- It is often used in combination with other surfactants to balance foam and gentleness.
Common questions
What is C11-15 Pareth-30 in beauty products?
C11-15 Pareth-30 is a man-made ingredient that helps water and oil stay blended in products like cleansers and lotions. It belongs to a group called ethoxylated alcohols, which are made by adding ethylene oxide to fatty alcohols. This process creates a mild surfactant that can clean without stripping too much moisture, though it may still be slightly drying for some skin types.
What does C11-15 Pareth-30 do in a beauty product?
It works by lowering the surface tension between oil and water, allowing them to mix into a stable emulsion. In cleansers, it helps lift dirt and oil from the skin so they can be rinsed away. The '30' in its name indicates a high degree of ethoxylation, which makes it milder and more water-soluble than shorter-chain versions.
Is C11-15 Pareth-30 safe for most people?
C11-15 Pareth-30 is considered safe for use in cosmetics at typical concentrations. The main concern is potential skin irritation for sensitive individuals and trace impurities from manufacturing, which are regulated. Overall, it is a well-tolerated synthetic emulsifier.
Who should be careful with C11-15 Pareth-30?
Individuals with very sensitive or compromised skin barriers who may react to ethoxylated 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.