Ingredient review
C9-11 Alkane/Cycloalkane
INCI: C9-11 ALKANE/CYCLOALKANE
A lightweight, non-greasy solvent that helps dissolve makeup and sunscreen while leaving a silky feel on skin.
In plain English
C9-11 Alkane/Cycloalkane is a mix of hydrocarbon molecules (9 to 11 carbons long) that are liquid at room temperature. It works like a gentle, fast-evaporating oil that helps dissolve stubborn makeup and sunscreen without leaving a heavy or sticky residue. Think of it as a lighter, less greasy alternative to mineral oil or coconut oil.
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
C9-11 Alkane/Cycloalkane 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 C9-11 Alkane/Cycloalkane.
- 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 blend of linear alkanes and cyclic alkanes (cycloalkanes) with 9 to 11 carbon atoms per molecule. It is produced by refining petroleum or through synthetic processes, resulting in a clear, odorless liquid that evaporates quickly on the skin.
How it works
When applied, the alkanes spread easily over the skin, dissolving oil-based impurities like makeup, sebum, and sunscreen. Because the molecules are small and volatile, they evaporate partially after application, leaving a thin, non-greasy film that feels silky and smooth. This makes it an excellent carrier for other ingredients and a base for cleansing products.
Pros
Lightweight and non-greasy
Unlike heavier oils, C9-11 Alkane/Cycloalkane evaporates quickly, leaving skin feeling silky rather than oily. This makes it ideal for oily or acne-prone skin types.
Effective makeup remover
Its solvent properties help dissolve long-wear and waterproof makeup without harsh rubbing, reducing irritation around the eyes and lips.
Cons and cautions
Petroleum-derived
This ingredient is typically sourced from petroleum refining, which may be a concern for those seeking plant-based or more sustainable options.
Potential for dryness
Because it evaporates, it can strip some natural oils from the skin if used in high amounts, especially in cleansing products without added moisturizers.
Best for
- People who wear heavy or waterproof makeup and want a gentle remover
- Those with oily or combination skin who prefer lightweight, non-greasy textures
Use caution if
- Individuals with very dry or compromised skin barriers may find it slightly drying if used alone
Usage tips
Safety summary
C9-11 Alkane/Cycloalkane is considered safe for cosmetic use at typical concentrations. It has low irritation and comedogenic potential, making it suitable for most skin types. Some individuals with very dry or sensitive skin may experience mild dryness if used excessively.
Research notes
Research on this specific blend is limited, but studies on similar hydrocarbon mixtures (e.g., C9-12 alkanes) indicate they are well-tolerated on skin and do not penetrate deeply. The Cosmetic Ingredient Review has deemed related ingredients safe for use in rinse-off and leave-on products.
Common label clues
- Typical concentration
- 1% to 30% depending on product type
- Regulatory status
- Approved for use in cosmetics in the EU, US, and other major markets. The Cosmetic Ingredient Review (CIR) panel has evaluated similar hydrocarbon blends and found them safe for topical use at typical concentrations.
- Common uses
- Makeup removers, Cleansing balms, Sunscreens, Hair oils
- Environmental note
- As a petroleum-derived ingredient, its production has a higher carbon footprint compared to plant-based alternatives. However, it is not known to bioaccumulate like some silicones.
Good to know
- C9-11 Alkane/Cycloalkane is often listed under 'Isoparaffin' on labels, but they are not exactly the same—isoparaffins are branched, while this blend includes both linear and cyclic forms.
- It is considered a volatile silicone alternative, offering similar slip and feel without the environmental persistence concerns of silicones.
Common questions
What is C9-11 Alkane/Cycloalkane in beauty products?
C9-11 Alkane/Cycloalkane is a mix of hydrocarbon molecules (9 to 11 carbons long) that are liquid at room temperature. It works like a gentle, fast-evaporating oil that helps dissolve stubborn makeup and sunscreen without leaving a heavy or sticky residue. Think of it as a lighter, less greasy alternative to mineral oil or coconut oil.
What does C9-11 Alkane/Cycloalkane do in a beauty product?
When applied, the alkanes spread easily over the skin, dissolving oil-based impurities like makeup, sebum, and sunscreen. Because the molecules are small and volatile, they evaporate partially after application, leaving a thin, non-greasy film that feels silky and smooth. This makes it an excellent carrier for other ingredients and a base for cleansing products.
Is C9-11 Alkane/Cycloalkane safe for most people?
C9-11 Alkane/Cycloalkane is considered safe for cosmetic use at typical concentrations. It has low irritation and comedogenic potential, making it suitable for most skin types. Some individuals with very dry or sensitive skin may experience mild dryness if used excessively.
Who should be careful with C9-11 Alkane/Cycloalkane?
Individuals with very dry or compromised skin barriers may find it slightly drying if used alone
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.