What Is C12-13 Alketh-4?
C12-13 Alketh-4 is a synthetic ingredient made by reacting a blend of C12 and C13 fatty alcohols with an average of four units of ethylene oxide, creating a polyethylene glycol ether. The fatty alcohols used come from petroleum or plant oils, while ethylene oxide is produced from ethylene gas. The reaction, called ethoxylation, links the alcohols and ethylene oxide under controlled heat and pressure, then the mixture is purified to remove unreacted materials and ensure consistent quality.
The cosmetic industry began using ethoxylated alcohols in the mid-20th century when formulators needed reliable, mild emulsifiers that would work in both water- and oil-based systems. Over time C12-13 Alketh-4 became a staple because its chain length and limited ethylene oxide units strike a balance between effective emulsifying power and low skin irritation.
Today you will mainly find C12-13 Alketh-4 in products where water and oil need to stay evenly mixed such as facial cleansers, light lotions, makeup removers, exfoliating scrubs, rinse-off masks, sunscreens and hair conditioners. It is favored in items designed for daily use because it is compatible with many other ingredients, remains stable across a broad pH range and rinses away easily without leaving a heavy residue.
C12-13 Alketh-4’s Cosmetic Benefits/Uses
Formulators turn to this ingredient for one key reason.
As an emulsifying agent it helps water and oil blend into a smooth, uniform mixture. This keeps a product from separating on the shelf, ensures each pump or scoop delivers the same ratio of active ingredients and gives the final formula a pleasing lightweight feel on skin or hair.
Who Can Use C12-13 Alketh-4
This emulsifier is generally well tolerated by most skin types. Normal, combination and oily skin tend to find it especially comfortable because it rinses clean without leaving a greasy film. Dry or sensitive skin can usually handle it too since the molecule is mild, yet anyone with a history of reacting to surfactants should proceed cautiously as the cleansing action could feel a bit stripping if used in high amounts or left on the skin for long periods.
C12-13 Alketh-4 is typically suitable for vegans and vegetarians. Although the fatty alcohol portion can be sourced from either petroleum or coconut/palm oils, no animal-derived materials are required for its production. Those who follow a strict plant-only lifestyle may still want brand confirmation to be sure a specific formula meets their ethical standards.
Current safety data show no known risks for pregnant or breastfeeding women when this ingredient is used in rinse-off or leave-on cosmetics at standard concentrations. Still, this is not medical advice and anyone who is expecting or nursing should have their personal skincare routine reviewed by a qualified healthcare professional.
The molecule does not absorb UV light or make skin more prone to sunburn so photosensitivity is not a concern. It is also odorless and colorless which helps reduce the chance of fragrance or dye-related cross reactions in finished products.
Potential Side Effects/Adverse Reactions
Individual responses to topical C12-13 Alketh-4 can differ. The effects listed below are possible yet unlikely for most users when the ingredient is used correctly and at appropriate levels in a well-formulated product.
- Mild skin irritation such as temporary redness or itching
- Contact dermatitis in those with pre-existing sensitivity to ethoxylated alcohols
- Dryness or tightness if the formula contains a high cleansing load and no counterbalancing hydrators
- Eye irritation or stinging if the product accidentally gets into the eyes before rinsing
- Allergic reaction presenting as hives or swelling, though this is rare
If any of these reactions occur stop using the product immediately and consult a healthcare professional.
Comedogenic Rating
Rating: 1/5. C12-13 Alketh-4 is a small, water-soluble emulsifier that readily rinses away, so it does not linger inside pores or form an occlusive film that could trap sebum and debris. Because it is usually used at low levels and in rinse-off formulas its likelihood of clogging pores is considered very low.
Suitable for acne-prone or breakout-prone skin.
As with many ethoxylated ingredients trace amounts of the processing by-product 1,4-dioxane can be present, but reputable manufacturers keep these levels well below regulatory limits and this impurity is not linked to comedogenicity.
Summary
C12-13 Alketh-4’s main job in cosmetics is to act as an emulsifier, helping water and oil mix so lotions stay uniform and cleansers wash off cleanly. Its balanced chain length gives enough surface activity to stabilize emulsions while staying mild on skin.
Although not a headline ingredient like hyaluronic acid or retinol it is quietly popular behind the scenes because it is dependable, cost-effective and plays nicely with a wide range of actives.
Current research and long-term marketplace use show it is safe for most people at typical cosmetic concentrations. Still, when trying any new product it is wise to do a quick patch test to make sure your individual skin agrees with the full formula.