Ingredient review
C8-9 Alkane/Cycloalkane
INCI: C8-9 Alkane/Cycloalkane
A lightweight, volatile hydrocarbon that helps products spread easily and evaporate quickly without leaving a greasy feel.
In plain English
C8-9 Alkane/Cycloalkane is a mixture of hydrocarbon molecules (8 to 9 carbons long) that are liquid at room temperature. It works like a very light oil that spreads easily on skin and then evaporates, leaving little to no residue. You'll often find it in makeup removers and cleansing balms because it helps dissolve makeup and sunscreen without needing heavy oils.
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
C8-9 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 C8-9 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 8 to 9 carbon atoms. It is produced from petroleum or natural gas and refined for cosmetic use.
How it works
When applied, the low surface tension allows it to spread quickly across the skin, dissolving oil-based impurities and makeup. Because it is volatile, it evaporates rapidly, leaving a dry, non-greasy finish. This makes it a popular alternative to silicones or heavier oils in lightweight formulas.
Pros
Lightweight feel
Evaporates quickly, leaving no heavy or sticky residue, making it ideal for oily or combination skin.
Effective solvent
Dissolves stubborn makeup and sunscreen without requiring harsh scrubbing, reducing irritation risk.
Cons and cautions
Petroleum-derived
Sourced from non-renewable fossil fuels, which may be a concern for environmentally conscious users.
Potential drying effect
Because it evaporates, it can strip natural oils if used excessively, especially on already dry skin.
Best for
- People who prefer lightweight, fast-absorbing textures
- Those looking for a silicone alternative in makeup removers
Use caution if
- Individuals with very dry or compromised skin barriers who may prefer richer emollients
- Anyone seeking exclusively plant-derived ingredients
Usage tips
Safety summary
C8-9 Alkane/Cycloalkane is considered safe for cosmetic use at typical concentrations. It has low irritation and comedogenic potential. However, as a volatile hydrocarbon, it may cause dryness if overused on sensitive or dry skin.
Research notes
Safety assessments by the Cosmetic Ingredient Review (CIR) panel and the European Chemicals Agency (ECHA) support its use in cosmetics. Studies show low acute toxicity and no significant skin sensitization. Long-term inhalation data are limited, but dermal exposure is considered safe.
Common label clues
- Typical concentration
- 1–20% in leave-on products; up to 50% in rinse-off products
- Regulatory status
- Approved for use in cosmetics by the FDA (as part of general hydrocarbon allowances) and by the European Commission (listed in Annex V as a permitted solvent).
- Common uses
- Makeup removers, Cleansing balms, Sunscreens, Hair oils
- Environmental note
- Derived from petroleum, a non-renewable resource. Some brands use bio-based alternatives like coconut alkanes for a more sustainable profile.
Good to know
- C8-9 Alkane/Cycloalkane is often used as a silicone alternative in 'clean beauty' formulations.
- It is considered safe by major cosmetic safety panels when used as intended.
Common questions
What is C8-9 Alkane/Cycloalkane in beauty products?
C8-9 Alkane/Cycloalkane is a mixture of hydrocarbon molecules (8 to 9 carbons long) that are liquid at room temperature. It works like a very light oil that spreads easily on skin and then evaporates, leaving little to no residue. You'll often find it in makeup removers and cleansing balms because it helps dissolve makeup and sunscreen without needing heavy oils.
What does C8-9 Alkane/Cycloalkane do in a beauty product?
When applied, the low surface tension allows it to spread quickly across the skin, dissolving oil-based impurities and makeup. Because it is volatile, it evaporates rapidly, leaving a dry, non-greasy finish. This makes it a popular alternative to silicones or heavier oils in lightweight formulas.
Is C8-9 Alkane/Cycloalkane safe for most people?
C8-9 Alkane/Cycloalkane is considered safe for cosmetic use at typical concentrations. It has low irritation and comedogenic potential. However, as a volatile hydrocarbon, it may cause dryness if overused on sensitive or dry skin.
Who should be careful with C8-9 Alkane/Cycloalkane?
Individuals with very dry or compromised skin barriers who may prefer richer emollients Anyone seeking exclusively plant-derived ingredients
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.