Ingredient review
Sodium C13-15 Pareth-8 Butyl Phosphate
INCI: Sodium C13-15 Pareth-8 Butyl Phosphate
A mild synthetic surfactant that helps cleansers foam and rinse without stripping the skin.
In plain English
This ingredient is a man-made soap-like molecule that helps water and oil mix together. In a cleanser, it creates a gentle foam and lifts dirt and makeup off your skin so they can be rinsed away. It is designed to be less harsh than traditional sulfates, making it a common choice for milder face washes.
Review score
Safety, usefulness, and evidence
Potentially useful with some tradeoffs
The evidence base is useful, but some claims depend heavily on the formula.
Risk flags are low for most users, though the finished product can still irritate.
- Source
- synthetic
- Evidence
- moderate
- Irritation
- low
- Clogging risk
- low
Quick decision guide
Useful, but context matters
Sodium C13-15 Pareth-8 Butyl Phosphate is generally a lower-concern ingredient when the full formula suits your skin.
Plain-English read
Treat this as a practical screening step before you compare products that contain this ingredient.
- Step 1Start with the score, then check the irritation and clogging risk before judging Sodium C13-15 Pareth-8 Butyl Phosphate.
- Step 2Use the "Best for" and "Use caution if" sections to match the ingredient to your skin, not just to a marketing claim.
- Step 3If a product stings, breaks you out, or worsens irritation, judge the finished formula and stop using it even if the ingredient scores well.
Score terms in plain English
Irritation risk
lowLess likely to sting, burn, or bother most users, though sensitive skin can still react.
Clogging risk
lowLess likely to feel heavy or contribute to clogged pores for most skin types.
Evidence level
moderateThere is useful support, but formula details and claim strength still matter.
What it is
A synthetic anionic surfactant derived from fatty alcohols and phosphoric acid. It belongs to a class of phosphate esters that are known for their mildness and ability to stabilize emulsions.
How it works
It reduces the surface tension between water and oil, allowing oily impurities to be suspended in water and rinsed off. Its phosphate group gives it a negative charge, which helps it interact gently with the skin's surface without stripping natural oils.
Pros
Mild foaming action
Creates a gentle lather that effectively removes dirt and excess oil without leaving skin feeling tight or stripped.
Good emulsifier
Helps blend water and oil phases in creams and lotions, resulting in a stable, smooth texture that spreads easily.
Cons and cautions
Not for ultra-sensitive skin
While milder than many sulfates, it can still cause slight stinging or dryness if your skin barrier is already compromised.
Synthetic origin
Made from petrochemical-derived fatty alcohols, which may be a concern for those seeking fully natural or biodegradable ingredients.
Best for
- People with normal to combination skin looking for a mild foaming cleanser
- Those who want to avoid harsher sulfates like SLS or SLES
Use caution if
- Individuals with severely damaged or inflamed skin barriers may prefer a non-foaming cleanser
Usage tips
Safety summary
Sodium C13-15 Pareth-8 Butyl Phosphate is considered safe for use in rinse-off cosmetics at typical concentrations. It has low skin irritation and sensitization potential, though individuals with very sensitive skin should patch test new products.
Research notes
Safety assessments by the Cosmetic Ingredient Review (CIR) panel have reviewed similar phosphate ester surfactants and found them safe for cosmetic use. Published studies indicate low acute toxicity and minimal skin irritation.
Common label clues
- Typical concentration
- 0.5% to 5%
- Regulatory status
- Approved for use in cosmetics in the EU, US, and other major markets. No specific concentration restrictions are imposed, but formulators typically keep it below 5% for leave-on products.
- Common uses
- Cleansers, Facial washes, Body washes, Emulsions
- Environmental note
- Synthetic surfactant; its phosphate content may contribute to aquatic nutrient concerns, but it is generally considered biodegradable.
Good to know
- This ingredient is often found in sulfate-free formulations as a gentler alternative.
- It is considered biodegradable under standard wastewater treatment conditions.
Common questions
What is Sodium C13-15 Pareth-8 Butyl Phosphate in beauty products?
This ingredient is a man-made soap-like molecule that helps water and oil mix together. In a cleanser, it creates a gentle foam and lifts dirt and makeup off your skin so they can be rinsed away. It is designed to be less harsh than traditional sulfates, making it a common choice for milder face washes.
What does Sodium C13-15 Pareth-8 Butyl Phosphate do in a beauty product?
It reduces the surface tension between water and oil, allowing oily impurities to be suspended in water and rinsed off. Its phosphate group gives it a negative charge, which helps it interact gently with the skin's surface without stripping natural oils.
Is Sodium C13-15 Pareth-8 Butyl Phosphate safe for most people?
Sodium C13-15 Pareth-8 Butyl Phosphate is considered safe for use in rinse-off cosmetics at typical concentrations. It has low skin irritation and sensitization potential, though individuals with very sensitive skin should patch test new products.
Who should be careful with Sodium C13-15 Pareth-8 Butyl Phosphate?
Individuals with severely damaged or inflamed skin barriers may prefer a non-foaming cleanser
Research sources
Ingredient reviews are educational and are not medical advice. Patch test new products and ask a licensed clinician about persistent irritation, allergies, pregnancy-specific questions, or diagnosed skin conditions.