What Is C12-13 Alketh-9?
C12-13 Alketh-9 is a man-made ingredient created by attaching polyethylene glycol (PEG) chains to a blend of synthetic fatty alcohols that each contain 12 or 13 carbon atoms. On average nine units of ethylene oxide are added to every fatty alcohol molecule, which is why the name ends in “-9.” These fatty alcohols are usually derived from coconut or petroleum sources, giving manufacturers a steady supply that is not affected by seasonal crops. The practice of linking ethylene oxide to oils and fats began in the mid-1900s when chemists were searching for safer, more versatile alternatives to soap. Today the process is carried out in closed reactors where the fatty alcohols are mixed with ethylene oxide gas under heat and pressure, then purified to remove unreacted materials.
Thanks to its balanced mix of oil-loving and water-loving parts, C12-13 Alketh-9 is prized as an emulsifier. You will often find it in face creams, body lotions, liquid foundations, makeup removers, hair conditioners, sunscreens, cleansing balms, sheet mask essences and exfoliating scrubs. It helps these products stay uniform from the factory to your bathroom shelf so every application feels the same.
C12-13 Alketh-9’s Cosmetic Benefits/Uses
In topical products C12-13 Alketh-9 serves one key purpose: it acts as an emulsifier. By sitting at the border between oil and water it keeps the two phases from separating, giving the final formula a smooth look and feel. A stable emulsion spreads more evenly on skin or hair, delivers active ingredients more consistently and resists breaking down when stored in warm or cold bathrooms.
Who Can Use C12-13 Alketh-9
C12-13 Alketh-9 is generally suitable for normal, oily, combination and dry skin types because it is used at low levels and is rinsed or left on without leaving a heavy residue. People with very sensitive or compromised skin should approach formulas containing any PEG ingredient with caution because broken or inflamed skin can be more reactive to surfactants. The ingredient itself is fully synthetic and is made from coconut or petroleum derived fatty alcohols rather than animal sources, so it is acceptable for vegans and vegetarians.
Current safety assessments show no specific risks for pregnant or breastfeeding women when the ingredient is used as intended in cosmetics. That said this is not medical advice and anyone who is pregnant or nursing should review their skincare routine with a qualified health professional to be safe.
C12-13 Alketh-9 is not known to cause photosensitivity, so it will not make skin more prone to sunburn. It is also compatible with most common active ingredients and does not interfere with color treated hair.
Potential Side Effects/Adverse Reactions
Individual reactions to topical C12-13 Alketh-9 vary. The points below outline potential side effects yet most people will not experience them if the product is well formulated and used as directed.
- Mild skin irritation such as stinging or itching, especially on very sensitive skin
- Temporary redness or flushing
- Contact dermatitis in people allergic to polyethylene glycol compounds
- Eye irritation if the product accidentally gets into the eyes
- Increased penetration of other ingredients through compromised skin which could heighten their effects
If any of these reactions occur stop using the product and seek advice from a healthcare professional.
Comedogenic Rating
Rating: 1/5. C12-13 Alketh-9 is a lightweight emulsifier that sits at the oil-water interface rather than forming an oily film on skin. It is normally used at very low concentrations so it does not add enough residue to block pores. As a result it is generally suitable for people who are prone to acne or breakouts. Because it is a PEG ether, any traces left on skin rinse away easily and do not oxidize into pore-clogging by-products. Only in unusually high amounts or in heavy formulations could it contribute to congestion.
Summary
C12-13 Alketh-9 is primarily an emulsifier that keeps oil and water mixed so lotions, creams and makeup stay smooth stable and pleasant to use. It does this by having one end that loves oil and another that loves water which lets it hold both phases together during manufacturing storage and application. While not the most famous ingredient on a label it is a popular workhorse behind the scenes because it is reliable cost-effective and compatible with many actives and fragrances.
Current safety reviews classify it as low risk for irritation or sensitization when used as intended. That said every skin type is unique so it is always wise to patch test a new product containing C12-13 Alketh-9 before adding it to your daily routine.