Ingredient review
Perfluorononylethyl Carboxydecyl Hexacosyl Dimethicone
INCI: PERFLUORONONYLETHYL CARBOXYDECYL HEXACOSYL DIMETHICONE
A high-performance film-former that helps makeup last longer and resist water, but it's a synthetic ingredient with limited biodegradability.
In plain English
This is a man-made molecule that combines silicone and fluorocarbon chemistry. In a cosmetic product, it spreads into a thin, flexible, water-resistant film on your skin or lashes. Think of it like a clear, breathable raincoat for your makeup—it helps foundation stay put through sweat and humidity, and makes mascara smudge-proof. Because it's a large polymer, it sits on the surface of the skin rather than being absorbed.
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 Hexacosyl 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 Hexacosyl 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 synthetic polymer that joins a perfluorinated chain (similar to Teflon) with a silicone backbone (dimethicone). This hybrid structure gives it both the smooth glide of silicones and the water/oil repellency of fluorocarbons.
How it works
When applied, the solvent evaporates and the polymer chains link together to form a continuous, flexible film. This film physically blocks water and oil from reaching the underlying makeup or sunscreen, while also helping pigments adhere to the skin. The silicone part provides a silky feel, and the fluorocarbon part boosts water resistance.
Pros
Excellent water resistance
The fluorocarbon part makes this ingredient highly repellent to water and sweat, so your makeup stays put through a workout or rainy day.
Smooth, non-greasy feel
The silicone component gives a silky, lightweight texture that spreads easily and doesn't leave a sticky residue.
Cons and cautions
Environmental persistence
As a fluorinated polymer, it is not readily biodegradable and can accumulate in the environment, raising concerns for eco-conscious users.
Can be hard to remove
The strong film it forms requires an oil-based or dual-phase cleanser to break down, which may be inconvenient or drying with repeated use.
Best for
- People who need long-wear, waterproof makeup for events or humid climates
- Those with oily or combination skin who want a matte, transfer-resistant finish
Use caution if
- Anyone with very dry or dehydrated skin, as the film can feel tight or accentuate flakiness
Usage tips
Safety summary
Generally recognized as safe for topical use at typical concentrations. It is not absorbed through intact skin and has low irritation and comedogenic potential. However, long-term environmental impact is a consideration.
Research notes
Most evidence comes from cosmetic chemistry literature and formulation studies. There are no major human safety trials, but the ingredient's large molecular size and low reactivity suggest minimal skin penetration. Environmental persistence is the primary concern.
Common label clues
- Typical concentration
- 1–10% in leave-on products
- Regulatory status
- Approved for use in cosmetics in the US (FDA), EU (CosIng), and many other regions. No specific concentration limits, but formulators typically keep it under 10%.
- Common uses
- Long-wear foundations, Waterproof mascaras, Sunscreens, Lip products
- Environmental note
- Perfluorinated compounds are of concern due to their persistence in the environment. This specific polymer is very large and may not be bioavailable, but its degradation products are not well studied.
Good to know
- This ingredient is often found in '24-hour wear' foundations and waterproof sunscreens.
- It is considered a 'high-performance' polymer and is more common in prestige or professional makeup lines.
Common questions
What is Perfluorononylethyl Carboxydecyl Hexacosyl Dimethicone in beauty products?
This is a man-made molecule that combines silicone and fluorocarbon chemistry. In a cosmetic product, it spreads into a thin, flexible, water-resistant film on your skin or lashes. Think of it like a clear, breathable raincoat for your makeup—it helps foundation stay put through sweat and humidity, and makes mascara smudge-proof. Because it's a large polymer, it sits on the surface of the skin rather than being absorbed.
What does Perfluorononylethyl Carboxydecyl Hexacosyl Dimethicone do in a beauty product?
When applied, the solvent evaporates and the polymer chains link together to form a continuous, flexible film. This film physically blocks water and oil from reaching the underlying makeup or sunscreen, while also helping pigments adhere to the skin. The silicone part provides a silky feel, and the fluorocarbon part boosts water resistance.
Is Perfluorononylethyl Carboxydecyl Hexacosyl Dimethicone safe for most people?
Generally recognized as safe for topical use at typical concentrations. It is not absorbed through intact skin and has low irritation and comedogenic potential. However, long-term environmental impact is a consideration.
Who should be careful with Perfluorononylethyl Carboxydecyl Hexacosyl Dimethicone?
Anyone with very dry or dehydrated skin, as the film can feel tight or accentuate flakiness
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.