What Is C12-14 Sec-Pareth-9?
C12-14 Sec-Pareth-9 is a man-made ingredient created by reacting synthetic secondary fatty alcohols that have 12 to 14 carbon atoms with roughly nine units of ethylene oxide. The result is a polyethylene glycol ether that looks like a clear to pale yellow liquid or paste and dissolves well in water and oils. Because the fatty alcohols are produced in a lab, the material is highly purified and consistent from batch to batch.
Ethoxylated alcohols like C12-14 Sec-Pareth-9 began appearing in personal care formulas in the 1970s when cosmetic chemists looked for milder alternatives to natural soaps. By adjusting the number of ethylene oxide units they found they could fine-tune cleansing strength and skin compatibility, which quickly made these ingredients popular in facial cleansers and lotions.
Manufacturing starts with secondary alcohols that are treated with ethylene oxide gas under heat and pressure. Each alcohol molecule adds an average of nine ethylene oxide units, giving the finished ingredient its balance of oil-loving and water-loving parts. After purification and quality checks it is shipped as a liquid or flakes ready for blending into finished products.
You will most often see C12-14 Sec-Pareth-9 in facial cleansers, micellar waters, makeup removers, lightweight lotions, sheet mask serums, anti-aging creams, hair conditioners and even some deodorant sticks where it helps solubilize fragrance oils.
C12-14 Sec-Pareth-9’s Cosmetic Benefits/Uses
Formulators include this ingredient because it delivers several technical benefits that improve product performance and skin feel.
- Cleansing: Its balanced structure lifts away excess oil, makeup and daily grime without leaving skin feeling tight
- Emulsifying: It helps blend oily and watery ingredients into a uniform mixture so the product does not separate on the shelf or during use
- Emulsion stabilising: Beyond simply forming an emulsion it strengthens the emulsion’s structure, giving creams and lotions a smooth texture through temperature changes and repeated opening of the package
Who Can Use C12-14 Sec-Pareth-9
This ingredient is generally well tolerated by all skin types. Oily and combination skins appreciate its light cleansing feel while dry or mature skins tend to have no trouble as long as the formula also contains moisturisers. Sensitive skin can usually handle it because it is milder than traditional soap but, as with any surfactant, very reactive or broken skin might notice a slight tingling if the product is left on for long periods.
C12-14 Sec-Pareth-9 is synthesised from laboratory made fatty alcohols and ethylene oxide so it contains no animal derived material. That makes it suitable for both vegans and vegetarians.
The Cosmetic Ingredient Review panel has found it safe for use during pregnancy and breastfeeding when it is formulated correctly and used as directed. This is not medical advice and anyone who is pregnant or nursing should run their skincare routine past a qualified healthcare provider just to be safe.
The ingredient does not absorb UV light and has no known link to photosensitivity, so it will not make skin more prone to sunburn.
Potential Side Effects/Adverse Reactions
Reactions to topical C12-14 Sec-Pareth-9 vary from person to person. The points below cover potential side effects that could occur in rare cases. When used in a properly formulated product most people experience none of these issues.
- Mild skin irritation such as redness, stinging or itching especially on very sensitive or damaged skin
- Contact dermatitis in individuals who develop an allergy to ethoxylated ingredients
- Eye irritation if a cleanser or lotion containing it accidentally gets into the eyes
- Excess dryness when used in high concentrations or in formulas without adequate moisturisers
- 1,4-dioxane trace contamination is possible if the manufacturer does not follow proper purification steps though modern quality control keeps levels far below safety limits
If you notice any negative reaction stop using the product immediately and seek advice from a pharmacist or healthcare professional.
Comedogenic Rating
Rating: 1 / 5
C12-14 Sec-Pareth-9 is highly water soluble and does not leave a heavy, oily film on the skin, which keeps its pore-clogging potential very low. It is usually used at modest levels and is often found in rinse-off products, further reducing the chance of buildup inside pores. For these reasons formulators consider it practically non-comedogenic, though not an absolute zero because any surfactant can disturb the skin barrier if overused.
Suitable for acne-prone and breakout-prone skin in most cases.
The only situations that might raise its comedogenic impact are very high concentrations in leave-on creams combined with rich occlusive oils, but such formulas are uncommon.
Summary
C12-14 Sec-Pareth-9 is a lab-made surfactant that cleanses skin, emulsifies oil and water, and stabilises emulsions. Its balanced structure of fatty alcohol and ethylene oxide units lets it wrap around dirt and sebum so they rinse away while holding a lotion or cream together so it stays smooth and even.
It is a workhorse ingredient rather than a headline grabber, showing up quietly in many cleansers, micellar waters, light lotions and some hair products. You will not see it promoted on product fronts, yet formulators like it because it performs reliably and is gentle compared with older soap-based options.
Safety reviews have found it low in toxicity, non-sensitising for most users and free of major reproductive or environmental concerns when properly purified. As with any new skincare product, a quick patch test is a smart step to make sure your skin agrees with the full formula.