What Is C9-13 Isoalkane?
C9-13 Isoalkane is a blend of lightweight branched hydrocarbons that contain between nine and thirteen carbon atoms. It is most commonly sourced from highly refined petroleum fractions. Through a series of controlled steps such as hydrocracking, distillation and isomerization, straight-chain molecules are rearranged into branched forms that feel silky rather than greasy on skin. The ingredient first showed up in cosmetics in the late 1970s when formulators were looking for a safer, low-odor alternative to traditional mineral oil. Because the blend is carefully purified it carries very little scent, evaporates predictably and leaves almost no residue, making it a formulator favorite.
You will find C9-13 Isoalkane in a wide range of products including cleansing oils, waterproof makeup removers, spray sunscreens, lightweight moisturizers, hair shine mists, stick deodorants, foundations and long-wear lip colors. Its versatility lies in its ability to dissolve oils and pigments while keeping textures light and pleasant.
C9-13 Isoalkane’s Cosmetic Benefits/Uses
Here is how this multitasker helps improve everyday beauty products:
- Solvent: Efficiently dissolves waxes, oils and pigments so formulas spread smoothly, feel weightless and remove stubborn makeup without tugging
- Viscosity controlling: Thins down heavy formulations or adds slip to gels and creams which helps achieve the ideal texture for sprays, lotions and balms
Who Can Use C9-13 Isoalkane
C9-13 Isoalkane is generally well tolerated by all skin types. Its light, non greasy feel makes it a good match for oily and combination skin while its ability to dissolve heavier emollients means it can still appear in products meant for normal and dry skin. Sensitive skin usually handles it well because the ingredient is highly refined and contains virtually no impurities that can trigger irritation.
The blend is petroleum derived and contains no raw materials from animals so it is suitable for both vegans and vegetarians, provided the finished product also meets cruelty free standards.
Available safety data shows no specific risks for pregnant or breastfeeding women when the ingredient is used topically in cosmetic concentrations. This is not medical advice and anyone who is pregnant or nursing should have their healthcare provider review any skincare routine just to be safe.
C9-13 Isoalkane does not make skin more reactive to sunlight and it is considered non photosensitizing. It also has no known interactions with common actives like retinoids or acids, which lets formulators pair it with almost anything.
Potential Side Effects/Adverse Reactions
Reactions to C9-13 Isoalkane vary from person to person. The following points describe potential side effects that are possible yet unlikely when the ingredient is formulated and used correctly
- Mild transient skin irritation such as redness or a stinging sensation
- Contact dermatitis in individuals allergic to hydrocarbon solvents
- Temporary eye irritation if the product accidentally gets into the eyes
- Worsening of breakouts in very acne prone skin when used in high concentration leave on products
- Respiratory discomfort when inhaled from aerosol or spray formats in poorly ventilated areas
If any of these effects occur stop using the product and seek advice from a qualified healthcare professional.
Comedogenic Rating
Rating: 1 / 5
C9-13 Isoalkane is a lightweight branched hydrocarbon that evaporates or absorbs quickly rather than sitting on the surface and clogging pores. Studies on similar isoparaffins show little tendency to trap dead skin cells or sebum, which keeps the score low. It lacks fatty acids that commonly feed acne bacteria, further reducing the risk.
Because of this low rating most people prone to blackheads or breakouts can generally use products containing C9-13 Isoalkane without issues, especially when it appears in wash off or low concentration leave on formulas.
The only time concerns may rise is when very high levels are used in heavy balms or thick foundations applied to already congested skin, as any occlusive film can potentially amplify existing blemishes.
Summary
C9-13 Isoalkane acts primarily as a solvent and viscosity controller. Its branched structure dissolves waxes, oils and pigments while keeping textures thin and silky so sprays, creams and sticks glide on smoothly and dry down without greasiness. This dual role has made it a quiet staple in modern formulations from waterproof makeup removers to spray sunscreens.
While not as famous as plant oils or silicones its consistent performance, low odor and favorable safety profile keep it popular among formulators who need a reliable non polar solvent.
Current data shows C9-13 Isoalkane is considered safe for topical use with minimal irritation or sensitization risk. Still, skin can react unpredictably so it is smart to patch test any new product that features this ingredient before incorporating it fully.