What Is C11-13 Alketh-9?
C11-13 Alketh-9 is a man-made ingredient created by attaching about nine units of ethylene oxide to a blend of fatty alcohols that have 11 to 13 carbon atoms. These fatty alcohols usually come from natural oils such as coconut or palm, though they can also be produced synthetically. The resulting substance is a clear to pale yellow liquid that dissolves easily in water and oil, which makes it handy for many cosmetic formulas.
The use of fatty alcohol ethoxylates in personal care dates back to the mid-20th century when chemists searched for gentler alternatives to harsh soaps. Over time formulators found that the specific C11-13 chain length paired with nine ethylene oxide units struck a good balance between mildness and cleaning power. This led to its adoption in shampoos and skin cleansers, and later in lotions, masks and wipes where a stable blend of oil and water is needed.
To make C11-13 Alketh-9 manufacturers first obtain the C11-13 fatty alcohols, purify them then pass ethylene oxide gas over the alcohols under controlled heat and pressure. The reaction adds the ethylene oxide “links” to the alcohol backbone. After purification and quality checks the liquid is ready to be blended into products.
You are most likely to find C11-13 Alketh-9 in face and body washes, liquid hand soaps, shampoos, exfoliating scrubs, makeup removers, sheet masks, micellar waters and lightweight lotions that aim to feel fresh rather than heavy.
C11-13 Alketh-9’s Cosmetic Benefits/Uses
This ingredient pulls double duty in cosmetic formulas
- Cleansing Its structure loosens dirt, oil and makeup so they can be rinsed away with water. Because it is milder than traditional sulfates it helps cleanse without leaving skin or hair feeling stripped
- Emulsifying It keeps oil and water mixed together in a smooth stable blend. This means creams stay uniform, clear gels do not separate and liquid cleansers feel consistent from the first pump to the last
Who Can Use C11-13 Alketh-9
C11-13 Alketh-9 is gentle enough for most skin types including normal, oily, dry and combination skin. Its mild cleansing action makes it a good fit for sensitive skin as well, though extremely reactive skin may prefer a shorter ingredient list in general.
The fatty alcohols used to make this ingredient are usually sourced from coconut or palm oil so the finished material is free of animal by-products. Because no animal-derived components or testing are required, products that carry a vegan or vegetarian claim can safely include C11-13 Alketh-9 as long as the overall formula meets those standards.
No specific warnings exist for pregnant or breastfeeding women when it is used in rinse-off or leave-on cosmetics at typical levels. This is not medical advice and anyone who is pregnant or nursing should check with a healthcare professional before adding new products to a routine.
C11-13 Alketh-9 does not make skin more prone to sunburn and it is stable under normal daylight so there are no special sun precautions related to this ingredient.
Potential Side Effects/Adverse Reactions
Reactions to any cosmetic ingredient can vary from person to person. The following list covers potential issues a small number of users might experience. When used correctly in a well-formulated product most people will not notice any of these effects.
- Mild skin irritation especially on already compromised or broken skin
- Temporary eye stinging if a high-foaming cleanser gets into the eyes
- Dryness or tightness in very dry climates when used in high-foaming washes multiple times a day
- Allergic contact dermatitis a rare immune response that presents as redness itching or small bumps
If you notice persistent redness burning or itching after using a product that contains C11-13 Alketh-9 stop using it and consult a healthcare professional.
Comedogenic Rating
Rating: 1 / 5 C11-13 Alketh-9 is water soluble and does not leave an occlusive film on skin which makes it unlikely to clog pores. It may sit alongside oily ingredients in a formula but on its own it rinses clean. Because of this low tendency to trap sebum or dead cells it earns a rating of 1 rather than 0, reflecting the slim chance of issues in very reactive or severely congested skin.
Most people who are prone to acne or breakouts can use products containing C11-13 Alketh-9 without added risk.
As with any surfactant heavy cleanser, pairing it with a non-comedogenic moisturizer can help keep the skin barrier balanced after washing.
Summary
C11-13 Alketh-9 works as a gentle cleanser and an emulsifier. Its ethoxylated fatty alcohol structure has a water loving end that grabs grime and a lipid friendly end that latches onto oils so it lifts away dirt while keeping oil and water mixed in stable lotions, gels and wipes.
It is a background player rather than a headline ingredient which means it shows up in plenty of everyday cleansers yet rarely gets called out on the front label. Formulators like it because it offers reliable mildness and is easy to blend with actives, fragrances and conditioning agents.
Safety data and long-term use in rinse-off and leave-on products point to a low risk profile. Most users tolerate it well though anyone trying a new product should still do a small patch test to be safe.