What Is C13-15 Pareth-21?
C13-15 Pareth-21 is a nonionic surfactant made by attaching about 21 units of ethylene oxide to fatty alcohols that contain 13 to 15 carbon atoms. These fatty alcohols usually come from renewable plant oils like coconut or palm or from synthetic petrochemical routes. The result is a clear to slightly hazy liquid that mixes easily with both oil and water.
Nonionic surfactants like this one entered cosmetic labs in the 1960s when formulators looked for gentle yet effective cleansers that would not interfere with charged ingredients. Over time C13-15 Pareth-21 became popular because it can clean skin and hair without creating too much foam or leaving a heavy residue.
The manufacturing process starts with the fatty alcohol feedstock. Under controlled temperature and pressure the alcohol reacts with ethylene oxide gas. By stopping the reaction after roughly 21 ethylene oxide units have attached to each alcohol molecule chemists create a consistent ingredient that blends smoothly into water-based or oil-in-water systems.
You will most often see C13-15 Pareth-21 in facial cleansers, body washes, shampoo, micellar water, makeup removers, exfoliating gels, sheet mask essences and lightweight lotions where a gentle cleansing boost or solubilizing effect is needed.
C13-15 Pareth-21’s Cosmetic Benefits/Uses
Formulators rely on this ingredient mainly for its cleansing ability.
As a cleanser C13-15 Pareth-21 loosens dirt, sweat and makeup so they rinse away with water. It does this while staying mild on skin and hair, which helps reduce the tight or squeaky feeling some stronger detergents leave behind. It also improves the way oils or fragrances disperse in a formula, so products stay clear and stable during their shelf life.
Who Can Use C13-15 Pareth-21
This surfactant is generally suitable for all skin types. Oily and combination skin benefit from its ability to lift excess sebum while dry or mature skin appreciate that it cleans without stripping natural moisture. Sensitive skin usually tolerates it thanks to its nonionic nature yet very reactive or compromised skin might still experience mild irritation, especially if the finished product contains a high overall surfactant load.
Most commercial supplies of C13-15 Pareth-21 come from plant-based fatty alcohols or fully synthetic sources so the ingredient itself can fit vegan and vegetarian lifestyles. Users who avoid animal-derived materials should verify that the final product and its supply chain are certified cruelty free.
The Cosmetic Ingredient Review panel and international regulatory agencies have not flagged C13-15 Pareth-21 as a concern for pregnancy or breastfeeding when used in rinse-off or leave-on products at typical levels. This is not medical advice and anyone who is pregnant or nursing should show the product label to a qualified clinician before adding it to a routine just to be safe.
The ingredient is not known to cause photosensitivity and does not increase the skin’s reactivity to sunlight. It is also compatible with most cosmetic actives and can be safely paired with exfoliating acids, retinoids or vitamin C without affecting their efficacy.
Potential Side Effects/Adverse Reactions
Responses to topical C13-15 Pareth-21 vary from person to person. The points below list potential side effects that could occur yet they are uncommon when the ingredient is used at appropriate levels in well-formulated products.
- Mild skin irritation such as redness or itching
- Transient stinging or burning sensation on very sensitive or broken skin
- Dryness or tight feeling if used in a formula with an overall high surfactant concentration
- Allergic contact dermatitis in individuals with a specific sensitivity to ethoxylated surfactants
- Eye irritation if the product accidentally gets into the eyes before rinsing
If any discomfort or visible reaction develops stop using the product and seek guidance from a healthcare professional or dermatologist.
Comedogenic Rating
Rating: 1 / 5
C13-15 Pareth-21 is highly water soluble and rinses away cleanly so it has very little chance of building up inside pores. Its fatty alcohol backbone is balanced by 21 ethylene oxide units that keep the molecule hydrophilic which further lowers the risk of pore blockage. Because it is almost always used in wash-off products the skin’s contact time is short, reducing any opportunity for clogging.
Suitable for acne-prone skin in most cases
Formulas that combine this surfactant with heavy oils, waxes or thick butters may still feel greasy on very oily complexions, so the finished product matters as much as the ingredient itself.
Summary
C13-15 Pareth-21 is a nonionic surfactant that lifts dirt, makeup and excess oil while helping fragrances and lipophilic ingredients disperse evenly. It performs these duties by surrounding oily grime with its dual oil-loving and water-loving structure so everything rinses off with water.
The ingredient enjoys moderate popularity: not as famous as sulphate-free headline makers yet widely used in gentle cleansers, micellar waters and lightweight lotions because it delivers reliable performance at a reasonable cost.
Current safety data show a low irritation profile when formulated at standard levels. Still, everyone’s skin is unique so it is smart to patch test any new product containing C13-15 Pareth-21 before regular use.