What Is Sodium C13-15 Alketh-8 Butyl Phosphate?
Sodium C13-15 Alketh-8 Butyl Phosphate is a surfactant derived from a blend of synthetic fatty alcohols with 13 to 15 carbon atoms, ethylene oxide, butyl alcohol and phosphoric acid that is then neutralized with sodium. The result is a sodium salt that dissolves well in water and helps lift away oil and dirt. It first appeared in shampoos and liquid soaps in the 1990s as chemists searched for gentle yet effective alternatives to sulfates. Production starts with fatty alcohols that are reacted with ethylene oxide to create C13-15 Pareth-8. This intermediate is then esterified with phosphoric acid and butanol, followed by neutralization with sodium hydroxide to yield the final ingredient.
Thanks to its surface-active nature it shows up in many rinse-off products including facial cleansers, body washes, shampoos, shaving foams and micellar waters. It can also be blended into makeup removers and exfoliating scrubs where a mild cleansing boost is needed.
Sodium C13-15 Alketh-8 Butyl Phosphate’s Cosmetic Benefits/Uses
Formulators rely on this ingredient for a single yet essential role in skincare and haircare products.
As a cleansing agent it lowers the surface tension between oil and water so grime, excess sebum and product residue can be rinsed away easily. It creates a light, creamy lather that feels gentle on skin and hair, helps keep formulas clear and stable and can improve rinse-off so fewer surfactants are needed overall.
Who Can Use Sodium C13-15 Alketh-8 Butyl Phosphate
This surfactant suits most skin types, including oily, combination, normal and dry, because it cleans without leaving a greasy residue or stripping too much moisture. People with highly reactive or allergy-prone skin may want to confirm that the overall formula is free of other triggers, but the ingredient itself is considered gentle.
Its raw materials are synthetic or plant-derived, not animal-derived, so it is appropriate for vegans and vegetarians as long as the finished product aligns with their stance on animal testing.
No research suggests problems for those who are pregnant or breastfeeding when the ingredient is used in rinse-off products. This is not medical advice and pregnant or nursing individuals should still clear any skincare routine with a doctor.
The ingredient does not cause photosensitivity and there are no known interactions with sunscreen actives.
Potential Side Effects/Adverse Reactions
Side effects and reactions to topical Sodium C13-15 Alketh-8 Butyl Phosphate can vary from one person to another. The following are potential issues yet they are uncommon when products are formulated and used as directed.
Dry or tight feeling if the cleanser is left on the skin too long or used too frequently
Temporary eye irritation if it accidentally gets into the eyes
Mild redness or itching in people hypersensitive to ethoxylated surfactants
If you notice any of these effects stop using the product and seek advice from a healthcare professional or dermatologist.
Comedogenic Rating
Rating: 0 / 5
Sodium C13-15 Alketh-8 Butyl Phosphate is a water-soluble surfactant that rinses off completely and does not leave oily residues behind, so it has virtually no tendency to clog pores. Its molecular structure keeps it from building up on skin or mixing with sebum in a way that could trap dead cells or bacteria.
Because of that, it is generally suitable for people who are prone to acne and breakouts.
No studies link this ingredient to worsening acne and it is usually paired with other mild surfactants in formulas intended for sensitive or blemish-prone skin. As always overall product composition and individual tolerance matter more than any single ingredient.
Summary
Sodium C13-15 Alketh-8 Butyl Phosphate is a gentle cleansing agent that lowers surface tension so oil, dirt and product buildup lift away easily when rinsed with water. Its ability to create a light lather while remaining mild allows formulators to achieve effective cleansing without relying on harsher sulfates, which can over-strip skin and hair.
Although you will not see it headlining every shampoo or face wash, it has carved out a steady niche in sulfate-free cleansers, micellar waters and shaving foams where a balance of mildness and efficiency is needed. Brands that focus on sensitive skin or modern low-foaming textures appreciate what it brings to the table.
Current safety assessments classify it as low risk in rinse-off products. Reported side effects are rare and usually mild, yet everyone’s skin is unique. Whenever you try a new product containing this or any other surfactant, do a quick patch test to make sure it plays well with your skin.