What Is C12-15 Alketh-4?
C12-15 Alketh-4 is a synthetic ingredient made by attaching ethylene oxide units to a blend of fatty alcohols that have chain lengths between 12 and 15 carbon atoms. On average, four ethylene oxide units are linked to each alcohol molecule, which is why the name ends with “-4.” The fatty alcohols themselves are created in a lab, often starting from plant oils or petroleum sources, then purified and reacted with ethylene oxide in a controlled setting. This reaction produces a clear or slightly cloudy liquid that dissolves well in water and oil.
C12-15 Alketh-4 first appeared in skin and hair care during the late twentieth century when manufacturers were looking for gentler alternatives to older emulsifiers. Because it is mild on skin, stable over a wide pH range, and easy to formulate with, it quickly found its way into many personal care products. Today you will see it on ingredient lists for facial cleansers, body washes, moisturizers, sunscreens, makeup removers, masks, and some styling creams. Its ability to blend oily and watery ingredients into a smooth, even texture makes it a favorite among formulators who want a light feel without heavy residues.
C12-15 Alketh-4’s Cosmetic Benefits/Uses
In cosmetics C12-15 Alketh-4 serves one main purpose that brings several practical advantages to a formula.
As an emulsifying agent it helps water and oil mix together, creating a stable cream, lotion, or gel that stays uniform over time. This keeps the product from separating on the shelf, gives it a pleasing texture, and allows the active ingredients to spread evenly across the skin or hair.
Who Can Use C12-15 Alketh-4
C12-15 Alketh-4 is generally suitable for all skin types, including oily, combination, normal and dry skin. Its lightweight feel and low likelihood of clogging pores make it a good choice for acne-prone complexions as well. Sensitive skin usually tolerates this emulsifier because it is nonionic and has a mild profile, though anyone with a known sensitivity to polyethylene glycol derivatives should proceed with caution.
The ingredient is made synthetically from plant or petroleum-derived fatty alcohols and ethylene oxide, with no animal by-products involved, so it aligns with vegan and vegetarian lifestyles. As always the finished product’s overall cruelty-free status depends on the brand’s testing policies.
C12-15 Alketh-4 is considered low risk for pregnant or breastfeeding women when used in topical cosmetics at the concentrations normally found on the market. This is not medical advice, and anyone who is pregnant or nursing should have a quick chat with a healthcare provider before adding new skincare to a routine.
The ingredient does not cause photosensitivity and does not make skin more prone to sunburn. It works equally well in rinse-off and leave-on formulas, and its performance is not affected by the presence of common actives like vitamin C or retinoids.
Potential Side Effects/Adverse Reactions
Reactions to topical C12-15 Alketh-4 vary from person to person. The points below cover potential side effects, but most users will not experience them when the ingredient is used correctly in a well-formulated product.
- Mild skin irritation brief redness or stinging, more likely on compromised or freshly exfoliated skin
- Contact dermatitis rare allergic response resulting in itching or a rash
- Eye irritation watering or burning if the product accidentally gets into the eyes
- Dryness a tight feeling after use, usually in higher concentrations or in very dry climates
If any of these effects occur stop using the product and consult a healthcare professional if symptoms persist or worsen.
Comedogenic Rating
Rating: 1/5. C12-15 Alketh-4 is a small, water-soluble emulsifier that quickly rinses away and leaves little residue on the skin, which makes it unlikely to block pores. It does not behave like heavier oils or waxes that can sit on the surface and trap debris, so the risk of triggering blackheads or whiteheads is considered very low.
Because of this low rating it is generally suitable for people who are prone to acne or frequent breakouts.
As with any ingredient the final product formula matters; if a cleanser or lotion also contains rich plant butters or silicones the overall pore-clogging potential may rise even though C12-15 Alketh-4 itself is non-problematic.
Summary
C12-15 Alketh-4 is mainly valued for its ability to act as an emulsifier, letting water and oil mingle so a product stays smooth stable and pleasant to use. By sitting at the water-oil boundary its small polyethylene glycol head attracts water while its fatty tail grabs onto oils, giving formulators a reliable way to create light lotions, creamy washes or fluid sunscreens without separation.
You will notice it most often in cleansers and moisturizers from mid-priced to luxury ranges, less so in minimalist or natural-only lines. Its popularity rests on being easy to work with, cost-effective and gentle which keeps it in steady though not headline-grabbing demand.
Safety reviews place C12-15 Alketh-4 in the low-risk category for topical use with only rare reports of irritation or allergy. Still skin can be unpredictable, so it is smart to patch test any new product containing this or any other ingredient before applying it to larger areas.