What Is C12-15 Alketh-7?
C12-15 Alketh-7 is a man-made ingredient created by attaching about seven units of ethylene oxide to a blend of synthetic fatty alcohols that range in length from 12 to 15 carbon atoms. The result is a clear to pale yellow liquid that behaves like a gentle soap in water-based formulas yet is mild enough for leave-on products. This class of ingredients first appeared in the late twentieth century when chemists looked for reliable alternatives to naturally sourced emulsifiers, which could vary from batch to batch. By controlling the chain length of the alcohol and the number of ethylene oxide units, manufacturers achieved consistent performance and safety.
Production begins with fatty alcohols that are often derived from petroleum or plant oils such as coconut or palm. These alcohols undergo ethoxylation, a controlled reaction where ethylene oxide gas is added under heat and pressure. The “7” in the name signals the average number of ethylene oxide units attached to each alcohol molecule. Once purified, the resulting liquid is blended into cosmetic bases where it helps oily and watery ingredients stay mixed.
You are likely to find C12-15 Alketh-7 in facial cleansers, lightweight moisturizers, makeup removers, sheet masks, sunscreens, body lotions and some anti-aging serums. It is favored in products that must feel non-greasy yet still look uniform on the shelf over time.
C12-15 Alketh-7’s Cosmetic Benefits/Uses
Although it has one primary role, that role is essential to the stability and feel of many formulas.
As an emulsifying agent, C12-15 Alketh-7 helps water and oil blend into a smooth, even mixture. This prevents separation in the bottle, gives products a consistent texture and helps active ingredients spread evenly across the skin for better performance.
Who Can Use C12-15 Alketh-7
This emulsifier is generally well tolerated by all skin types including oily, combination, normal and dry because it is used at low levels and has a mild cleansing action. Sensitive or compromised skin can usually handle it too, although formulas with a high percentage of surfactants or multiple ethoxylated ingredients may feel a bit drying so those users should watch for tightness or redness.
C12-15 Alketh-7 is synthetic and contains no animal derived components, so it is suitable for vegans and vegetarians provided the finished product is certified cruelty free by the brand.
Current safety data show no specific risks for pregnant or breastfeeding women when this ingredient is applied topically in cosmetic concentrations, but this is not medical advice. Anyone who is expecting or nursing should run all skincare products past a qualified health professional to be extra sure.
It does not make skin more sensitive to the sun and it has no known influence on the effectiveness of sunscreens or other daytime products.
Potential Side Effects/Adverse Reactions
Reactions to topical C12-15 Alketh-7 differ from person to person. The points below outline potential side effects yet most people will not experience them when the ingredient is used correctly in a well-formulated product.
- Mild skin irritation such as temporary redness or stinging
- Dryness or tightness if the formula is highly cleansing or if skin is already dehydrated
- Allergic contact dermatitis in individuals who are sensitive to ethoxylated surfactants
- Eye irritation if the product accidentally gets into the eyes
- Enhanced penetration of other actives which could intensify their irritating potential
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. Despite originating from fatty alcohols, the ethoxylation process turns C12-15 Alketh-7 into a water-friendly molecule that rinses clean and does not linger in pores. It is used at low levels, lacks a greasy finish and has no history of clogging skin in published cosmetic safety reviews. Overall it is considered suitable for acne-prone or breakout-prone skin.
No known interactions with common acne treatments such as benzoyl peroxide or salicylic acid have been reported, and it is not known to trap dead skin cells or sebum.
Summary
C12-15 Alketh-7 is chiefly an emulsifier that keeps water and oil blended so products stay smooth, spread evenly and feel light on the skin. It achieves this by pairing a short oily tail with several water-loving ethylene oxide units, allowing it to sit at the oil-water boundary and hold the two phases together.
While not the most spotlighted ingredient in marketing copy, formulators reach for it because it is reliable, mild and cost effective so it appears in a wide range of everyday cleansers, lotions and sunscreens.
Current data show it is low risk for irritation or comedogenicity when used at cosmetic levels. Still, skin can react unpredictably to any new formula so performing a small patch test before full use is always a smart step.