C9-14 Isoalkane: What Is It, Cosmetic Uses, Benefits & Side Effects

Curious about this ingredient? In this article we're explaining exactly what it is and why it's used within cosmetic formulations.
Updated on: June 24, 2025
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All information on this page is verified using publicly available nomenclature standards and reference materials from The Personal Care Products Council (PCPC) and the European Commission's CosIng database. Our analyses are based on technical data from these sources to ensure accuracy and reliability.

What Is C9-14 Isoalkane?

C9-14 Isoalkane is a clear lightweight liquid made up of branched hydrocarbon chains that range from nine to fourteen carbon atoms. These chains come from petroleum that has been highly refined to remove impurities. The ingredient was first introduced to cosmetics in the 1970s as a safer more stable alternative to older harsher solvents. Through careful distillation chemists separate the desired chain lengths then use hydrogenation to improve purity and keep the material odor free.

Because it spreads easily without feeling greasy C9-14 Isoalkane has earned a place in many product categories. You will find it in long wear foundations, waterproof mascaras, makeup removers, sunscreens, hair sprays, antiperspirants, body oils, sheet masks, anti aging serums and lightweight moisturizers.

C9-14 Isoalkane’s Cosmetic Benefits/Uses

Its main roles help formulas feel better on the skin and perform more reliably.

  • Solvent – dissolves oils, waxes or active ingredients so they mix evenly. This keeps color cosmetics smooth, prevents clumping in mascaras and allows sunscreens to spread in a thin protective layer
  • Viscosity controlling – thins thick formulas or fine-tunes texture giving products a silky fluid feel that glides on easily and dries quickly without residue

Who Can Use C9-14 Isoalkane

C9-14 Isoalkane is generally considered suitable for all skin types including oily, combination, normal and dry because it feels weightless and does not leave a heavy residue. Sensitive skin usually tolerates it as well since it is chemically inert and fragrance free. The only group that may want to be cautious is people with extremely compromised skin barriers such as those with active eczema or open wounds because any solvent can sting when skin is raw.

The ingredient itself is petro-derived, not animal-derived, so it is acceptable for both vegans and vegetarians. It is also free of common animal by-products like lanolin or beeswax.

Current data shows no known reproductive toxicity, so products containing C9-14 Isoalkane are not automatically off limits for pregnant or breastfeeding women. That said this is not medical advice and anyone who is expecting or nursing should review their personal care routine with a healthcare professional to be extra safe.

C9-14 Isoalkane does not make skin more sensitive to sunlight and it has no known interactions with UV exposure. It is also odorless which can be helpful for users who prefer fragrance free formulas.

Potential Side Effects/Adverse Reactions

Everyone’s skin is different so reactions to topical C9-14 Isoalkane can vary. The points below list potential side effects that could occur even though most people will not experience them when the ingredient is used correctly in a finished product.

  • Mild skin irritation in rare cases, mainly if applied to broken or highly sensitive skin
  • Contact dermatitis for individuals with a specific allergy to hydrocarbons or other formula components
  • Eye irritation if the liquid accidentally gets into the eyes during makeup removal or application
  • Temporary dryness for users whose skin reacts to solvent-type ingredients by losing a small amount of surface lipids

If any redness, burning or prolonged discomfort occurs stop using the product and consult a healthcare professional.

Comedogenic Rating

Rating: 1/5

C9-14 Isoalkane earns a low score because its branched hydrocarbon chains sit on the surface then evaporate rather than soaking into pores. It does not leave a heavy film or feed acne-causing bacteria so the chance of clogging is minimal.

That makes it generally suitable for people who are prone to acne or breakouts.

One extra note: formulas that combine C9-14 Isoalkane with highly occlusive waxes or butters could still feel heavier overall so consider the full ingredient list if congestion is a concern.

Summary

C9-14 Isoalkane works as a solvent that dissolves oils, pigments and filters, and as a viscosity controller that thins thick mixtures for a lighter feel. Its lightweight volatile nature lets products glide on smoothly, dry fast and resist clumping.

The ingredient is moderately popular in long-wear makeup, sunscreens and sprays because it delivers performance without greasiness. It is less common in rich creams where a more nourishing feel is desired.

Safety data show it is non sensitising, non toxic and rarely irritating. Even so everyone’s skin is unique so patch testing a new product is always a smart step.

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