Ingredient review
C12-13 Pareth-9
INCI: C12-13 PARETH-9
A gentle synthetic cleanser that helps remove dirt and oil without stripping the skin, but may cause irritation for very sensitive skin types.
In plain English
C12-13 Pareth-9 is a man-made cleansing ingredient that helps water and oil mix together so you can wash away makeup, sunscreen, and excess oil. It is part of a family of ingredients called ethoxylated alcohols, which are known for being milder than traditional sulfates like SLS. While it is generally considered gentle, it can still be drying or irritating for some people, especially if used in high concentrations or left on the skin.
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
C12-13 Pareth-9 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 C12-13 Pareth-9.
- 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 made by reacting a fatty alcohol (C12-13) with ethylene oxide, resulting in a molecule that can attract both water and oil.
How it works
It reduces the surface tension between oil and water, allowing oily impurities to be rinsed away with water. In formulas, it helps create a stable emulsion and a creamy, foamy lather.
Pros
Gentle cleansing
C12-13 Pareth-9 is milder than many traditional sulfates, making it a good choice for daily use without over-stripping the skin.
Versatile formulator
It works well in both rinse-off and leave-on products, helping to create stable, pleasant textures.
Cons and cautions
Potential irritation
Even though it is gentler than SLS, it can still cause stinging, redness, or dryness for those with sensitive or eczema-prone skin.
Ethoxylation concerns
The manufacturing process can produce trace amounts of 1,4-dioxane, a possible carcinogen, though reputable brands purify their ingredients to safe levels.
Best for
- People with normal to oily skin looking for a gentle cleanser
- Those who want a sulfate-free alternative for daily cleansing
Use caution if
- Individuals with very dry, compromised, or highly sensitive skin
- Anyone with a known allergy to ethoxylated ingredients
Usage tips
Safety summary
C12-13 Pareth-9 is considered safe for use in cosmetics at typical concentrations. The main concern is potential skin irritation for sensitive individuals and trace contamination with 1,4-dioxane, which is regulated and minimized by quality manufacturers.
Research notes
Studies on similar ethoxylated alcohols indicate low acute toxicity and mild to moderate skin irritation potential. The Cosmetic Ingredient Review has deemed related ingredients safe when formulated to be non-irritating.
Common label clues
- Typical concentration
- Usually 0.5% to 5% in rinse-off products; lower in leave-on 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 reviewed similar ethoxylated alcohols and found them safe at typical concentrations.
- Common uses
- Cleansers, Shampoos, Body washes, Makeup removers, Lotions
- Environmental note
- Ethoxylated surfactants can be slow to biodegrade in some conditions, but many are now formulated to be more environmentally friendly. Check for 'readily biodegradable' claims on the product.
Good to know
- The number '9' refers to the average number of ethylene oxide units attached, which influences its water solubility and mildness.
- It is often used in 'sulfate-free' cleansers as a gentler alternative to sodium lauryl sulfate.
Common questions
What is C12-13 Pareth-9 in beauty products?
C12-13 Pareth-9 is a man-made cleansing ingredient that helps water and oil mix together so you can wash away makeup, sunscreen, and excess oil. It is part of a family of ingredients called ethoxylated alcohols, which are known for being milder than traditional sulfates like SLS. While it is generally considered gentle, it can still be drying or irritating for some people, especially if used in high concentrations or left on the skin.
What does C12-13 Pareth-9 do in a beauty product?
It reduces the surface tension between oil and water, allowing oily impurities to be rinsed away with water. In formulas, it helps create a stable emulsion and a creamy, foamy lather.
Is C12-13 Pareth-9 safe for most people?
C12-13 Pareth-9 is considered safe for use in cosmetics at typical concentrations. The main concern is potential skin irritation for sensitive individuals and trace contamination with 1,4-dioxane, which is regulated and minimized by quality manufacturers.
Who should be careful with C12-13 Pareth-9?
Individuals with very dry, compromised, or highly sensitive skin Anyone with a known allergy 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.