C12-13 Alketh-3: 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 C12-13 Alketh-3?

C12-13 Alketh-3 is a non-ionic surfactant made by attaching an average of three units of ethylene oxide to synthetic fatty alcohols with 12 to 13 carbon atoms. The result is a clear to slightly hazy liquid that mixes well with both oil and water. Developed in the mid-20th century when chemists were looking for gentler alternatives to soap, it has since become a workhorse ingredient in modern skin and hair care.

The production starts with plant- or petroleum-derived fatty alcohols that are purified, then reacted with ethylene oxide in a controlled environment. The amount of ethylene oxide added determines the “3” in its name. This short ethoxylate chain keeps the molecule small enough to rinse away easily yet large enough to stabilize emulsions.

Because it helps oils and water stay blended, C12-13 Alketh-3 turns up in many product types: facial cleansers, lightweight lotions, moisturizers, sunscreens, rinse-off masks, hair conditioners and even some color cosmetics. Formulators like it because it is compatible with a wide pH range and plays well with most other ingredients.

C12-13 Alketh-3’s Cosmetic Benefits/Uses

The main role of C12-13 Alketh-3 is as an emulsifier. By lowering the surface tension between oil and water, it keeps creams, lotions and cleansers from separating, giving the final product a smooth uniform texture that feels pleasant on skin and spreads evenly.

Who Can Use C12-13 Alketh-3

This ingredient is generally well tolerated by all skin types, including oily, dry and combination skin. Its mild nature and low usage level mean that even sensitive skin usually gets along with it, though very reactive skin may still prefer formulas with fewer surfactants overall.

C12-13 Alketh-3 is produced from synthetic or plant-derived fatty alcohols and contains no animal by-products, so it fits vegan and vegetarian lifestyles.

Current data shows no specific risks for pregnant or breastfeeding women when the ingredient is used in rinse-off or leave-on cosmetics. Still, this is not medical advice. Anyone who is pregnant or nursing should check with a healthcare professional before adding new products to a routine, just to be safe.

The molecule does not make skin more sensitive to sunlight, so it is not considered photosensitising. It is also fragrance free and non-volatile, making it unlikely to trigger scent-related headaches.

Potential Side Effects/Adverse Reactions

Responses to any cosmetic ingredient differ from person to person. The list below covers potential side effects of topical C12-13 Alketh-3, but most users will not notice these issues when the product is formulated and used as intended.

Transient stinging or tingling on very broken or abraded skin

Mild dryness if used in a high-foaming cleanser without adequate moisturisers

Rare contact irritation or redness in individuals with surfactant sensitivities

Eye irritation if the product is not meant for the eye area and accidentally gets in the eyes

If any irritation or discomfort occurs discontinue use and consult a healthcare professional.

Comedogenic Rating

Rating: 1 / 5. C12-13 Alketh-3 is highly water soluble and used at low levels, so it is unlikely to linger on skin or mix with sebum long enough to block pores. Its molecular structure is dominated by the ethoxylated portion, which makes the ingredient more hydrophilic and less prone to forming an occlusive film. As a result it is generally suitable for people who are prone to acne or breakouts. Because it functions mainly as an emulsifier rather than a heavy emollient, it does not add significant oil load to a formula. Only extremely sensitive or congested skin types might notice issues, most often when the overall product contains several other pore-clogging ingredients.

Summary

C12-13 Alketh-3 is primarily an emulsifier and mild non-ionic surfactant. By reducing surface tension between oil and water, it keeps creams, lotions and cleansers stable and silky and it helps these products rinse away without leaving a heavy residue. The ingredient shows up in many mainstream skin and hair care lines, yet it rarely gets star billing because it works behind the scenes rather than providing a visible sensory claim.

Current safety data and long-standing use indicate a low risk of irritation or comedogenicity for most users. Still, skin can be unpredictable so it is wise to perform a small patch test when trying any new product that contains this or any other surfactant.

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