Ingredient review
Perfluorononylethyl Carboxydecyl Lauryl/Behenyl Dimethicone
INCI: PERFLUORONONYLETHYL CARBOXYDECYL LAURYL/BEHENYL DIMETHICONE
A high-tech film former that helps makeup and sunscreen stay put, but its environmental persistence raises concerns.
In plain English
This ingredient is a synthetic hybrid of silicone and fluorinated compounds. It spreads easily on skin, forms a flexible, water-resistant film, and helps other ingredients stay in place. Think of it as a clear, breathable shield that keeps your makeup from sliding off or your sunscreen from washing away. It's not absorbed into skin but sits on the surface.
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
Perfluorononylethyl Carboxydecyl Lauryl/Behenyl Dimethicone 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 Perfluorononylethyl Carboxydecyl Lauryl/Behenyl Dimethicone.
- 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 large molecule combining a silicone backbone (dimethicone) with fluorinated carbon chains and fatty alcohol-derived groups. It is engineered to be both water-repellent and spreadable.
How it works
When applied, the solvent evaporates and the molecules link into a thin, flexible film on the skin. The fluorinated part repels water and oil, while the silicone part gives a smooth, silky feel. This film locks in other ingredients and resists rub-off.
Pros
Excellent water resistance
Helps makeup and sunscreen survive sweat, humidity, and swimming without breaking down.
Smooth, non-greasy feel
Spreads like a silicone, leaving a silky finish that doesn't feel heavy or sticky.
Cons and cautions
Environmental persistence
Fluorinated parts of the molecule are very stable and can accumulate in the environment, raising ecological concerns.
Limited skin absorption data
While not known to penetrate deeply, there is little published research on long-term dermal exposure to this specific compound.
Best for
- People who need long-wear makeup or water-resistant sunscreen
- Those with normal to oily skin who want a matte, stay-put finish
Use caution if
- Individuals with very dry or flaky skin, as films can emphasize texture
Usage tips
Safety summary
Generally considered safe for topical use at typical concentrations. Irritation and allergy are rare. The main concern is environmental persistence rather than direct human toxicity.
Research notes
Most evidence comes from manufacturer safety data and general knowledge of silicones and fluoropolymers. Independent peer-reviewed studies on this exact molecule are limited. The ingredient is widely used in commercial products with a long history of consumer use.
Common label clues
- Typical concentration
- 0.5% to 5%
- Regulatory status
- Approved for use in cosmetics in the US (FDA), EU, and many other regions. No specific restrictions, but fluorinated compounds are under increasing environmental scrutiny.
- Common uses
- Long-wear foundations, Waterproof sunscreens, Lip products, Eye makeup
- Environmental note
- Fluorinated silicones are highly persistent. They do not readily break down in nature and may contribute to bioaccumulation. Some brands are moving away from them for this reason.
Good to know
- This ingredient is often found in 'transfer-proof' or '24-hour wear' products.
- It is not water-soluble, so standard water-based cleansers may not remove it completely.
Common questions
What is Perfluorononylethyl Carboxydecyl Lauryl/Behenyl Dimethicone in beauty products?
This ingredient is a synthetic hybrid of silicone and fluorinated compounds. It spreads easily on skin, forms a flexible, water-resistant film, and helps other ingredients stay in place. Think of it as a clear, breathable shield that keeps your makeup from sliding off or your sunscreen from washing away. It's not absorbed into skin but sits on the surface.
What does Perfluorononylethyl Carboxydecyl Lauryl/Behenyl Dimethicone do in a beauty product?
When applied, the solvent evaporates and the molecules link into a thin, flexible film on the skin. The fluorinated part repels water and oil, while the silicone part gives a smooth, silky feel. This film locks in other ingredients and resists rub-off.
Is Perfluorononylethyl Carboxydecyl Lauryl/Behenyl Dimethicone safe for most people?
Generally considered safe for topical use at typical concentrations. Irritation and allergy are rare. The main concern is environmental persistence rather than direct human toxicity.
Who should be careful with Perfluorononylethyl Carboxydecyl Lauryl/Behenyl Dimethicone?
Individuals with very dry or flaky skin, as films can emphasize texture
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.