What Is Sodium C13-15 Pareth-8 Butyl Phosphate?
Sodium C13-15 Pareth-8 Butyl Phosphate is a synthetic surfactant made from a mix of plant derived C13-C15 fatty alcohols that are reacted with about eight units of ethylene oxide, then further processed with butyl phosphate and neutralized with sodium. The result is a water-soluble powder or liquid that carries both oil-loving and water-loving parts, which is why it behaves so well at breaking up grime and oils on skin or hair.
Surfactants like this entered the cosmetic scene in the late 1960s when formulators wanted milder alternatives to harsh soaps. By tweaking natural fatty alcohols with modern chemistry they created ingredients that clean effectively without stripping skin. Over time Sodium C13-15 Pareth-8 Butyl Phosphate proved reliable in giving rich foam and stable emulsions, so it is now common in wash-off products.
You will mainly spot it in shampoos, body washes, facial cleansers, bubble baths, makeup removers, baby washes, sheet mask essences and some light lotions that need a touch of cleansing power to rinse off smoothly.
Sodium C13-15 Pareth-8 Butyl Phosphate’s Cosmetic Benefits/Uses
This multitasking surfactant supports several key roles in a formula
- Cleansing agent – lifts dirt, sweat and makeup from skin or hair so they can be rinsed away with water
- Foaming agent – creates a creamy lather that helps spread the product evenly and gives a pleasant sensory feel
- Emulsifying agent – keeps oil and water based ingredients blended which improves product stability and texture
Who Can Use Sodium C13-15 Pareth-8 Butyl Phosphate
This surfactant is generally well tolerated by normal, oily and combination skin since it removes excess sebum without leaving a heavy film. Sensitive skin can usually handle it too because it is milder than traditional sulfates, though formulas with high percentages may feel drying on very dry or compromised skin that already lacks natural lipids.
The ingredient is synthesized from plant based fatty alcohols and contains no animal by products so it suits both vegans and vegetarians. Most manufacturers also classify it as cruelty free.
Current safety data shows no specific risks for pregnant or breastfeeding women when used in rinse off or leave on levels common to cosmetics. This is not medical advice so anyone who is expecting or nursing should still check with their healthcare provider before starting a new product just to be safe.
Sodium C13-15 Pareth-8 Butyl Phosphate does not absorb UV light or alter skin sensitivity to the sun, therefore it is not considered photosensitizing. It is also fragrance free and colorless, making it unlikely to interfere with other active ingredients in a routine.
Potential Side Effects/Adverse Reactions
Responses to topical ingredients vary by individual. The following list covers potential side effects yet these reactions are uncommon when a product is properly formulated and used as directed.
- Skin dryness
- Mild irritation or stinging on compromised or freshly shaved skin
- Transient redness
- Eye irritation if product accidentally gets into the eyes
- Rare allergic contact dermatitis in those sensitized to ethoxylated surfactants
If any of these reactions occur stop using the product and consult a qualified healthcare professional.
Comedogenic Rating
Rating: 1/5 – Sodium C13-15 Pareth-8 Butyl Phosphate is a highly water-soluble surfactant that rinses away almost completely, leaving little residue behind to clog pores. Its molecular structure prefers to stay in the water phase rather than deposit on skin so it poses minimal risk of trapping oil or dead skin cells. Because of this low residue profile it is generally suitable for people who are prone to acne or breakouts.
The small chance of buildup comes from formulas that combine it with heavier emollients or leave-on conditioners, which is why it earns a 1 instead of a perfect 0.
Summary
Sodium C13-15 Pareth-8 Butyl Phosphate acts as a gentle cleanser, foaming booster and emulsifier. Its dual oil-loving and water-loving ends surround grime so it can be lifted off skin or hair, whip air into a creamy lather for a pleasant wash experience and keep oil and water mixed for a smooth stable product.
While not as famous as sulfates or classic nonionic surfactants, it appears frequently in modern shampoos, body washes and facial cleansers that aim for mildness with a satisfying foam. Formulators appreciate its versatility and ease of use so its presence is quietly widespread even if consumers rarely notice the name on the label.
Current safety reviews rate it as low risk with only occasional mild irritation reported in leave-on products. Still, every skin type is unique so it is smart to patch test any new product containing this ingredient before full use.