What Is C12-15 Alketh-2 Phosphate?
C12-15 Alketh-2 Phosphate is a synthetic ingredient created by attaching phosphoric acid to ethoxylated fatty alcohols that have 12 to 15 carbon atoms and an average of two ethylene oxide units. The fatty alcohols usually come from plant oils such as coconut or palm so the base material is renewable even though the final molecule is made in a lab. First the fatty alcohols are reacted with ethylene oxide to make the “Alketh-2” part then the resulting material is treated with phosphoric acid to form a blend of mono- and di-esters. Chemists began exploring this class of phosphate esters in the late 1970s as a way to improve the stability of emulsions without using higher levels of traditional surfactants. Over time the ingredient proved useful in skin care formulas because it offers dependable performance at low use levels and has a mild sensory profile.
You are most likely to find C12-15 Alketh-2 Phosphate in face and body lotions, moisturizers, sunscreen creams, foundations, leave-on hair conditioners, wash-off masks and anti-aging serums. Brands lean on it when they need an ingredient that can keep oils and water blended while still feeling light on the skin.
C12-15 Alketh-2 Phosphate’s Cosmetic Benefits/Uses
Its main job in a formula is listed as emulsifying, which brings several practical benefits.
As an emulsifier it helps water and oil stay mixed so the product remains smooth and uniform from the first pump to the last application. This improves the texture, spreads active ingredients evenly and prevents separation during storage, letting the product deliver consistent performance and a pleasant feel on the skin or hair.
Who Can Use C12-15 Alketh-2 Phosphate
This emulsifier is considered suitable for most skin types including oily, combination, normal and dry skin because it has a light feel and does not leave a greasy residue. Sensitive skin generally tolerates it well since it is used at low levels and carries little irritation potential, although anyone with a known sensitivity to phosphate esters should stay cautious.
The ingredient is synthetic but starts from plant-derived fatty alcohols so it fits vegan and vegetarian preferences. No animal-sourced materials are involved at any stage of its manufacture.
Current safety assessments do not flag any specific risks for pregnant or breastfeeding women at the concentrations used in cosmetics. That said this is not medical advice. Anyone who is pregnant or nursing should always show their skincare routine to a qualified doctor to be safe.
C12-15 Alketh-2 Phosphate does not make skin more prone to sunburn so it is not considered photosensitizing. It also plays well with common actives like retinol, vitamin C and niacinamide without causing known incompatibilities.
Potential Side Effects/Adverse Reactions
Side effects from topical use of C12-15 Alketh-2 Phosphate can vary from person to person. The following list covers potential reactions, though they are uncommon for most users when the ingredient is included at standard cosmetic levels.
- Mild skin irritation: rare stinging or redness, typically short lived
- Contact dermatitis: localized rash or itching in individuals allergic to phosphate esters or ethoxylated compounds
- Eye irritation: temporary discomfort if the product accidentally gets into the eyes
If you notice any of these reactions stop using the product and consult a healthcare professional for guidance.
Comedogenic Rating
Rating: 1/5. C12-15 Alketh-2 Phosphate is used at low concentrations, stays mostly in the water phase of a formula and has a light, non-oily finish so it shows very little tendency to block pores. In practical terms people who are prone to acne or breakouts usually tolerate it without extra congestion. Because it is an emulsifier rather than a heavy fatty ingredient the risk of clogging pores is minimal, though the full formula it sits in ultimately determines how pore-friendly a product feels.
Summary
C12-15 Alketh-2 Phosphate is a lab-made emulsifier that keeps the oil and water parts of creams, lotions and conditioners blended, which leads to smoother texture, better spread and steady delivery of active ingredients. It achieves this by pairing an oil-loving tail with a phosphate head that likes water, allowing it to sit at the oil-water interface and hold everything together with very little weight.
While not as famous as household names like glycerin or hyaluronic acid, it quietly shows up in many mainstream and indie formulas because chemists appreciate its reliability, mildness and plant-derived backbone.
Current safety data rate it as low risk for irritation or sensitization when used at normal cosmetic levels. Still, skin can be unpredictable, so it is smart to patch test any new product that contains it to make sure your skin stays happy.