What Is C12-13 Pareth-12 Carboxylic Acid?
C12-13 Pareth-12 Carboxylic Acid is a synthetic ingredient made by linking fatty alcohols that have 12 to 13 carbon atoms with about 12 units of ethylene oxide, then adding a carboxylic acid group at one end. The fatty alcohols usually come from coconut or palm kernel oil, giving the molecule a part that likes oil, while the ethylene oxide units create a part that likes water. This mix of oil loving and water loving sections is what makes it useful in many rinse-off products.
The idea of joining fatty alcohols with ethylene oxide dates back to the mid-20th century when chemists were looking for gentler soaps that could handle hard water. Over time, tweaks were made and the carboxylic acid version of these molecules was introduced to improve mildness and boost foaming. Today, manufacturers create it in large reactors where fatty alcohols react with ethylene oxide under heat and pressure, followed by a controlled oxidation step that adds the acid group. Quality checks make sure each batch has roughly 12 ethylene oxide units on average.
You will mainly see C12-13 Pareth-12 Carboxylic Acid in shampoos, facial cleansers, body washes, micellar waters and makeup removing wipes. It can also show up in bubble baths and hand soaps where rich foam and easy rinsing are important. Because it is mild and helps other surfactants work better, it is popular in formulas aimed at sensitive skin.
C12-13 Pareth-12 Carboxylic Acid’s Cosmetic Benefits/Uses
In everyday skin and hair care products, this ingredient plays one key role.
Cleansing: C12-13 Pareth-12 Carboxylic Acid helps lift dirt, oil and makeup from the surface of skin and hair so they can be rinsed away with water. Its balanced structure lets it create a creamy lather while staying gentle, which can reduce dryness or tightness often linked to harsher soaps. It also improves the overall texture of a formula, making washes feel smoother and easier to spread.
Who Can Use C12-13 Pareth-12 Carboxylic Acid
This gentle cleanser suits most skin types, including normal, oily, combination, dry and sensitive skin. Because it foams well without stripping the skin’s natural barrier, people who are easily irritated often tolerate it better than stronger sulfates. Those with very dry or compromised skin should still look for formulas that pair it with moisturizers to prevent any tight feel.
The fatty alcohol portion is sourced from plants and the molecule is made entirely by chemical reactions, so it contains no animal derived material. That makes products formulated with it suitable for vegans and vegetarians provided the rest of the ingredient list meets their standards.
Current safety data show no specific risks for women who are pregnant or breastfeeding when this ingredient is used in rinse off products. This is not medical advice and anyone who is expecting or nursing should ask a healthcare professional before adding new skincare just to be safe.
C12-13 Pareth-12 Carboxylic Acid is not known to increase photosensitivity, so it will not make skin more likely to burn in the sun. It is also biodegradable under normal wastewater conditions which can be a plus for consumers looking for environmentally mindful options.
Potential Side Effects/Adverse Reactions
Responses to topical C12-13 Pareth-12 Carboxylic Acid vary from one person to another. The points below describe possible, not probable, reactions. In a well formulated product most users will not notice any of these issues.
- Mild skin irritation such as redness or itching, especially on already compromised skin
- Eye stinging if the cleanser is not rinsed out promptly
- Temporary dryness or tightness when used in very high concentrations or without follow up hydration
- Rare allergic contact dermatitis for people sensitive to ethoxylated surfactants
If any discomfort or reaction appears stop using the product and seek advice from a healthcare professional.
Comedogenic Rating
Rating: 0–1 (very low)
C12-13 Pareth-12 Carboxylic Acid is highly water soluble and designed for rinse-off products, so it does not stay on the skin long enough to block pores. It lacks heavy oils or waxy molecules that typically cause congestion, giving it an almost non-comedogenic profile.
In practical terms it is considered safe for people prone to acne or breakouts.
Because the ingredient is biodegradable and easily removed with water, any residue left behind after cleansing is negligible, further lowering its pore-clogging potential.
Summary
C12-13 Pareth-12 Carboxylic Acid is a mild surfactant whose main job is cleansing. Its structure pairs an oil-loving tail with a water-loving chain capped by a carboxylic acid group, allowing it to surround dirt and oil so they wash away with ease while producing a creamy foam and keeping irritation low.
Although it is not as famous as sulfates or newer glucosides, formulators value it for its balance of gentleness, foam quality and compatibility with sensitive skin, so you will spot it in a fair share of shampoos, face washes and micellar waters.
Current safety reviews show it is well tolerated in rinse-off products with only rare reports of irritation or allergy. As with any new skincare item it is smart to patch test first to make sure the whole formula agrees with your skin.