What Is C12-13 Alketh-10 Phosphate?
C12-13 Alketh-10 Phosphate is a surfactant created by linking medium-chain fatty alcohols that contain 12 to 13 carbon atoms with about ten units of ethylene oxide, then attaching a phosphate group to the resulting molecule. The fatty alcohols can be sourced from coconut or palm oil, although fully synthetic versions also exist. First introduced in the late 1970s as part of a new class of mild surfactants, the material gained popularity when formulators looked for gentler alternatives to traditional sulfates. You might still see the older name C12-13 Pareth-10 Phosphate in vintage formulation guides.
Manufacturing starts with the fatty alcohols, which are reacted with ethylene oxide to produce the ethoxylated base. This step boosts water solubility. The intermediate is then treated with phosphoric acid, creating a mixture of mono- and di-esters. After neutralising the acid with sodium or potassium hydroxide, the finished ingredient is usually delivered as a clear to slightly hazy liquid.
Because it combines cleaning power with the ability to stabilise oil-in-water mixtures, C12-13 Alketh-10 Phosphate shows up in a wide range of products: daily facial cleansers, micellar waters, shampoo, body wash, exfoliating masks, lightweight lotions and even some tinted moisturisers. Its mildness lets brands market formulas to sensitive-skin users while still achieving a satisfying foaming or creamy texture.
C12-13 Alketh-10 Phosphate’s Cosmetic Benefits/Uses
This ingredient contributes two main performance benefits when added to a formula:
- Cleansing – breaks up oil, dirt and makeup so they can be rinsed away, creating a gentle yet effective lather that leaves skin and hair feeling refreshed without a tight after-feel
- Emulsifying – helps water and oil stay mixed, giving lotions, creams and cleansing milks a stable, uniform texture that resists separation over time
Who Can Use C12-13 Alketh-10 Phosphate
C12-13 Alketh-10 Phosphate is generally well tolerated by most skin types, including oily, combination and normal skin, thanks to its mild cleansing profile. People with sensitive or easily irritated skin often find it gentler than sulfate-based surfactants, though anyone with an already compromised skin barrier or severe eczema might still prefer formulas with even milder, non-ionic cleansers.
The fatty alcohols used to make this ingredient are typically sourced from coconut or palm oil, or produced synthetically, so no animal-derived matter is involved. This makes it compatible with vegan and vegetarian lifestyles, provided the finished product has not been tested on animals and the brand’s overall ethics align with cruelty-free standards.
C12-13 Alketh-10 Phosphate has no known hormonal activity or significant skin penetration, so it is not expected to pose a problem during pregnancy or while breastfeeding. That said, this is not medical advice; anyone who is pregnant or nursing should show the full ingredient list of any new product to a qualified healthcare professional before use.
The molecule does not make skin more reactive to sunlight, so it is not considered photosensitising. Outside of the rare chance of irritation, there are no special precautions linked to season, time of day or climate.
Potential Side Effects/Adverse Reactions
Reactions to topical C12-13 Alketh-10 Phosphate vary from person to person. The points below outline potential, yet uncommon, side effects. When the ingredient is used correctly in a well-formulated product most users will not encounter these issues.
- Skin dryness or tightness if used in high concentrations or washed off without proper moisturisation
- Transient stinging or redness on very sensitive or compromised skin
- Allergic contact dermatitis in individuals who develop a specific sensitivity to the molecule
- Mild eye irritation if the cleanser accidentally gets into the eyes
If any discomfort, redness or rash develops while using a product containing this ingredient stop using it and seek advice from a healthcare professional.
Comedogenic Rating
Rating: 1/5
C12-13 Alketh-10 Phosphate is a water-dispersible surfactant that rinses clean without forming a greasy film, so it has little tendency to lodge inside pores. The phosphate group and ethoxylated chain make the molecule strongly attracted to water and less likely to linger on skin. As a result it is unlikely to trigger new pimples, making it a comfortable choice for acne-prone users.
Any clogging that might be noticed in a finished product is more often linked to heavier emollients or waxes that share the formula rather than to this surfactant itself.
Summary
C12-13 Alketh-10 Phosphate works mainly as a cleanser and emulsifier. Its surfactant head lifts away oil and dirt while the ethoxylated chain stabilises emulsions so water and oil stay blended. These dual skills let formulators create face washes shampoos and lightweight lotions that feel gentle yet still perform.
Although it never became a headline ingredient like sulfates or cocamidopropyl betaine it enjoys steady behind-the-scenes use in modern mild cleansers especially those marketed for sensitive skin.
Overall safety data are solid. The ingredient is non sensitising for most people has no known hormonal activity and breaks down readily in water. As with any new skincare product it is wise to perform a small patch test first to rule out personal sensitivities.