What Is Sodium C11-15 Alketh-7 Carboxylate?
Sodium C11-15 Alketh-7 Carboxylate is a synthetic surfactant made by reacting fatty alcohols that contain 11 to 15 carbon atoms with ethylene oxide, then converting the resulting alcohol ethoxylate into a carboxylate salt using sodium. The finished material is a free-flowing powder or liquid that dissolves easily in water and works well in both hard and soft water.
The fatty alcohols used as the starting point usually come from plant oils such as coconut or palm. As the cosmetics industry searched for gentler alternatives to traditional soaps during the late twentieth century, chemists discovered that turning these plant-derived alcohols into ethoxylated carboxylates created surfactants that clean effectively without the high pH of soap. Over time this ingredient, originally listed as Sodium C11-15 Pareth-7 Carboxylate, gained popularity thanks to its good skin tolerance and compatibility with other mild cleansing agents.
Manufacturing begins with the extraction and purification of the C11-15 fatty alcohol blend, followed by controlled ethoxylation that adds about seven ethylene oxide units on average. The ethoxylate is then reacted with monochloroacetic acid to introduce the carboxyl group before neutralization with sodium hydroxide gives the final sodium salt. Strict process control keeps by-products low and ensures batch-to-batch consistency.
You will most often find Sodium C11-15 Alketh-7 Carboxylate in facial cleansers, micellar waters, body washes, baby shampoos, foaming masks and exfoliating scrubs where a gentle yet effective cleansing base is needed.
Sodium C11-15 Alketh-7 Carboxylate’s Cosmetic Benefits/Uses
In personal care formulas this ingredient serves a single but important purpose.
As a cleansing agent it lowers the surface tension of water so oils, dirt and makeup can be lifted off skin and rinsed away. It produces a light creamy lather, works in a wide pH range, is mild enough for daily use and helps stabilize foam created by other surfactants which improves the overall sensory experience of a wash-off product.
Who Can Use Sodium C11-15 Alketh-7 Carboxylate
This mild surfactant suits most skin types including normal, combination, oily, sensitive and even baby skin thanks to its gentle cleansing action and neutral pH. Extremely dry or compromised skin may feel a slight tightness if the formula is not balanced with extra emollients but in well rounded products it performs fine for them as well.
The fatty alcohols used to make the ingredient are sourced from plants and the rest of the manufacturing steps are synthetic, so no animal derived materials are involved. That makes it acceptable for both vegans and vegetarians.
Current safety assessments have not flagged any reproductive or developmental issues related to topical use. Pregnant and breastfeeding individuals can generally use products containing this surfactant, yet this is not medical advice and it is best to show any planned skincare routine to a qualified doctor for personal guidance.
Sodium C11-15 Alketh-7 Carboxylate does not increase photosensitivity, so there is no special sun care precaution connected to the ingredient itself beyond the usual daily SPF recommendation.
Potential Side Effects/Adverse Reactions
Reactions to topical Sodium C11-15 Alketh-7 Carboxylate vary from person to person. The points below list potential side effects only, and most people will not experience them when the ingredient has been properly formulated and used as intended.
- Mild eye irritation if product accidentally enters the eyes
- Temporary stinging or redness on very sensitive or broken skin
- Slight dryness or tightness when used in high concentrations without moisturizers
- Rare allergic contact dermatitis in individuals already sensitized to ethoxylated surfactants
- Increased irritation when combined with harsh exfoliating acids or strong fragrances in the same formula
If any discomfort, persistent redness or swelling occurs stop using the product and seek advice from a healthcare professional.
Comedogenic Rating
Rating: 1/5
Sodium C11-15 Alketh-7 Carboxylate is a water-soluble surfactant that rinses off completely and does not leave an oily film behind, so it has very little potential to clog pores. Its molecular structure is designed to bind to dirt and oils then wash away, rather than linger on the skin. For these reasons it earns a low comedogenic score of 1.
That means the ingredient is generally suitable for skin that is prone to acne or breakouts.
Because it is normally used in rinse-off cleansers, any minimal residue left on the skin is quickly removed, which further reduces the chance of congestion.
Summary
Sodium C11-15 Alketh-7 Carboxylate is a mild plant-derived synthetic surfactant whose main job is cleansing. It lowers water’s surface tension so oils, dirt and makeup can be lifted away, all while keeping the formula’s pH skin-friendly. It also creates a soft foam and helps stabilize lather from other gentle surfactants, giving products a pleasant feel.
Although not as widely known as classic cleansers like sodium lauryl sulfate, formulators value it for its combination of mildness, performance and easy compatibility which has made it a quiet staple in micellar waters, baby washes and sensitive-skin face cleansers.
Current safety assessments show low irritation potential and no significant systemic concerns when used as intended. Nonetheless everyone’s skin is different so it is wise to patch test any new product that contains this ingredient to be sure it agrees with your skin.