Ingredient review
Ceteareth-4 Phosphate
INCI: Ceteareth-4 Phosphate
A gentle emulsifier and surfactant that helps blend oil and water in cleansers and creams, with low irritation potential.
In plain English
Ceteareth-4 Phosphate is a mild cleansing and emulsifying ingredient. It helps mix oil and water so that products like lotions and cleansers stay smooth and don't separate. It also helps remove dirt and makeup without stripping the skin's natural moisture barrier.
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
- semi synthetic
- Evidence
- moderate
- Irritation
- low
- Clogging risk
- low
Quick decision guide
Useful, but context matters
Ceteareth-4 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 Ceteareth-4 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 semi-synthetic compound made from cetearyl alcohol (a fatty alcohol from plant sources) and phosphoric acid. It belongs to a class of ingredients called alkyl phosphates, which are known for being gentle on skin.
How it works
It works by reducing the surface tension between oil and water, allowing them to blend into a stable emulsion. In cleansers, it helps lift dirt and oil from the skin so they can be rinsed away easily. Its phosphate group gives it a mild, non-stripping cleansing action.
Pros
Gentle on skin
Unlike harsher sulfates, Ceteareth-4 Phosphate cleanses without stripping the skin's natural oils, making it suitable for daily use.
Improves product texture
It helps create smooth, creamy formulas that feel luxurious on the skin and don't separate over time.
Cons and cautions
Potential palm oil source
The fatty alcohols used may come from palm oil, which has environmental concerns unless certified sustainable.
Less research available
Compared to more common emulsifiers, there is less published research on this specific ingredient, though its safety profile is well-established by analogy.
Best for
- People with normal to dry skin looking for a gentle cleanser
- Anyone who prefers mild, non-stripping surfactants in their routine
Use caution if
- Those with known allergies to fatty alcohols (rare)
Usage tips
Safety summary
Ceteareth-4 Phosphate is considered safe for use in cosmetics at typical concentrations. It has low irritation and comedogenic potential, making it suitable for most skin types. As with any ingredient, patch test if you have sensitive skin.
Research notes
While specific studies on Ceteareth-4 Phosphate are limited, the broader class of alkyl phosphate surfactants has been reviewed by safety panels and found to be safe. Its mildness is supported by its chemical structure and widespread use in gentle formulations.
Common label clues
- Typical concentration
- 0.5% to 5%
- Regulatory status
- Approved for use in cosmetics in the US, EU, and many other regions. The Cosmetic Ingredient Review (CIR) panel has evaluated similar alkyl phosphates and found them safe at typical concentrations.
- Common uses
- Cleansers, Lotions, Creams, Makeup removers
- Environmental note
- Sourcing of the fatty alcohol component may involve palm oil. Look for products with RSPO-certified palm or plant-based alternatives for a more sustainable choice.
Good to know
- It is often used in combination with other emulsifiers to improve stability.
- The '4' in its name refers to the average number of ethylene oxide units, which affects its water solubility.
Common questions
What is Ceteareth-4 Phosphate in beauty products?
Ceteareth-4 Phosphate is a mild cleansing and emulsifying ingredient. It helps mix oil and water so that products like lotions and cleansers stay smooth and don't separate. It also helps remove dirt and makeup without stripping the skin's natural moisture barrier.
What does Ceteareth-4 Phosphate do in a beauty product?
It works by reducing the surface tension between oil and water, allowing them to blend into a stable emulsion. In cleansers, it helps lift dirt and oil from the skin so they can be rinsed away easily. Its phosphate group gives it a mild, non-stripping cleansing action.
Is Ceteareth-4 Phosphate safe for most people?
Ceteareth-4 Phosphate is considered safe for use in cosmetics at typical concentrations. It has low irritation and comedogenic potential, making it suitable for most skin types. As with any ingredient, patch test if you have sensitive skin.
Who should be careful with Ceteareth-4 Phosphate?
Those with known allergies to fatty alcohols (rare)
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.