What Is Sodium C11-15 Pareth-7 Carboxylate?
Sodium C11-15 Pareth-7 Carboxylate is a synthetic ingredient made by attaching about six units of ethylene oxide to fatty alcohols that fall within the C11 to C15 carbon length range. Those fatty alcohols are usually derived from plant oils such as coconut or palm though they can also come from petroleum sources. After the ethoxylation step, the material is reacted with chloroacetic acid then neutralized with sodium hydroxide, creating a water-soluble salt with both oily and water-loving parts.
The idea of blending fatty alcohols with small chains of ethylene oxide dates back to the mid-20th century when chemists were looking for milder surfactants to replace harsh soaps. As cosmetic formulas grew more sophisticated, converting part of the molecule into a carboxylate salt produced an even gentler surfactant that keeps working in hard water. By the late 1990s this specific version, noted by the “7” that signals an average of seven repeating units, began appearing in shampoos and facial cleansers aimed at sensitive skin.
Today you will most often spot Sodium C11-15 Pareth-7 Carboxylate in face and body washes, micellar waters, baby shampoos, shower gels, makeup removers, clay masks and some lightweight moisturizers that need a touch of cleansing action to rinse away cleanly. It is favored when formulators want a mild yet effective surfactant that can also help oil and water stay mixed.
Sodium C11-15 Pareth-7 Carboxylate’s Cosmetic Benefits/Uses
In cosmetics this ingredient mainly serves as a multitasking surfactant that cleanses skin while supporting the overall stability of the formula.
- Cleansing: Lifts away dirt, excess oil and makeup without stripping skin of its natural moisture, giving products a gentle, low-irritation wash off profile
- Emulsifying: Helps oil and water blend smoothly so lotions, gels and masks stay uniform during storage and feel consistent during use
Who Can Use Sodium C11-15 Pareth-7 Carboxylate
This ingredient suits most skin types including normal, dry, combination, oily and sensitive because it is a mild surfactant that cleans without excessive stripping. People with very dry or compromised skin may still prefer formulas where it is paired with extra moisturizers to counteract any possible tight feel, but the ingredient itself is not inherently harsh.
It is typically considered vegan and vegetarian friendly since the fatty alcohols are most often sourced from plants such as coconut or palm. However some suppliers can use petroleum or animal by-products so anyone following a strict lifestyle should look for brands that confirm plant based sourcing.
Current safety data shows no known risks for pregnant or breastfeeding women when used topically in rinse off or leave on cosmetics. This is not medical advice and anyone who is pregnant or nursing should review all skincare products with a qualified healthcare provider to be sure they are comfortable with every ingredient used.
Sodium C11-15 Pareth-7 Carboxylate does not increase sun sensitivity and has no photosensitizing properties. It also plays well with most other common skincare ingredients and does not interfere with actives like vitamin C or retinoids.
Potential Side Effects/Adverse Reactions
Individual responses to topical Sodium C11-15 Pareth-7 Carboxylate can vary. The following are potential but uncommon effects; most people will not experience them when the ingredient is properly formulated and used as directed.
- Mild skin irritation
- Eye stinging if the product accidentally gets into eyes
- Dryness or tightness when used in high concentrations without added moisturizers
- Allergic contact dermatitis in users who are sensitized to ethoxylated surfactants
- Increased irritation when combined with other potent cleansers or exfoliants in the same routine
If any discomfort, redness or swelling develops stop using the product and consult a healthcare professional.
Comedogenic Rating
Rating: 1/5
Sodium C11-15 Pareth-7 Carboxylate is highly water soluble and designed to rinse away cleanly, so it does not linger on the skin long enough to clog pores. Its molecular structure is dominated by a polar, hydrophilic portion that discourages it from remaining in the follicle, giving it a very low likelihood of triggering blackheads or whiteheads. For these reasons it earns a 1 rather than a perfect 0, as any surfactant can potentially cause minor film-forming when paired with heavy oils.
Overall this ingredient is considered suitable for acne-prone or breakout-prone skin.
Because it frequently appears alongside richer emollients in creamy cleansers, the finished product’s full formula—not the surfactant itself—ultimately determines whether a cleanser feels pore-clogging. Reading the complete ingredient list is helpful if you are especially sensitive.
Summary
Sodium C11-15 Pareth-7 Carboxylate acts chiefly as a mild cleanser and secondary emulsifier. The hydrophobic fatty alcohol chain binds to oil and debris while the ethoxylated, carboxylate head pulls those impurities into water so they rinse away, leaving skin feeling fresh yet comfortable. Its dual nature also helps stabilize emulsions so lotions, gels and micellar waters stay homogenous during shelf life.
Although not as famous as classic ingredients like sodium lauryl sulfate or cocamidopropyl betaine, it has carved out a quiet niche in modern gentle cleansers, baby shampoos and micellar formulas that target sensitive skin.
Current safety reviews show it is well tolerated in both rinse-off and leave-on products when used at standard cosmetic levels with irritation risks considered low. As with any new skincare product a patch test is a smart precaution to confirm personal compatibility.