C12-15 Alketh-12: 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 C12-15 Alketh-12?

C12-15 Alketh-12 is a man-made ingredient created by attaching about twelve units of ethylene oxide to a blend of synthetic fatty alcohols that have chain lengths between twelve and fifteen carbon atoms. This process converts oily alcohols into a water-loving substance, turning them into a polyethylene glycol ether. The ingredient first appeared in the late twentieth century when formulators were searching for reliable alternatives to naturally sourced emulsifiers that could be produced at scale with consistent quality. To make it, chemists start with purified C12-15 fatty alcohols, react them with ethylene oxide gas under controlled heat and pressure, then purify the resulting liquid to remove any unreacted materials.

Because of its ability to mix oil and water, C12-15 Alketh-12 shows up in many personal care products. It is common in lightweight facial moisturizers, gel-cream lotions, cleansing milks, makeup removers, sheet masks, hair conditioners and color-protecting treatments. You may also find it in sunscreens and anti-aging serums where it helps keep the formula uniform so the active ingredients spread evenly on the skin.

C12-15 Alketh-12’s Cosmetic Benefits/Uses

Formulators rely on C12-15 Alketh-12 for one main job that supports product performance and sensory appeal.

As an emulsifying agent it binds water and oil phases together, creating smooth stable mixtures that resist separation on the shelf and during use. This stability helps ensure each application delivers the same level of hydration, conditioning or protection. A good emulsion also feels lighter, spreads more easily and leaves less greasy residue, qualities consumers often prefer in modern skincare and haircare products.

Who Can Use C12-15 Alketh-12

Because it is lightweight and non greasy, C12-15 Alketh-12 is generally well tolerated by all skin types including oily, combination, normal and dry skin. Sensitive skin can usually handle it too since the molecule is large enough to sit on the surface and is not known to penetrate deeply, though very reactive skin may prefer formulas where it appears in low amounts.

The ingredient is synthetic and made from petrochemical ethylene oxide plus lab produced fatty alcohols so it contains no animal-derived matter. That means products featuring C12-15 Alketh-12 are suitable for vegans and vegetarians as long as the rest of the formula is also free of animal ingredients.

Current safety data do not show any specific risks for women who are pregnant or breastfeeding when the ingredient is used topically as part of a finished cosmetic. Still, this is not medical advice and anyone expecting or nursing should run any skincare product past a qualified healthcare provider to be safe.

C12-15 Alketh-12 does not make skin more sensitive to sunlight and has no known interactions with UV exposure, so daytime use does not require special precautions beyond regular sunscreen habits.

Potential Side Effects/Adverse Reactions

Individual responses to topical ingredients can differ. The points below list potential side effects that could occur even though most people will not notice any problems when the ingredient is used at the levels found in properly formulated cosmetics.

  • Mild skin irritation
  • Transient redness or warmth after application
  • Eye irritation if the product accidentally gets into the eyes
  • Allergic contact dermatitis in individuals already sensitised to polyethylene glycols or ethoxylated alcohols

If you experience any of the above issues discontinue use and seek advice from a healthcare professional

Comedogenic Rating

Rating: 1/5 C12-15 Alketh-12 is mostly water soluble and used at low concentrations, which means it tends to rinse or rub off rather than sit inside pores where it could harden into plugs. Its molecular size and structure make it unlikely to trap dead skin cells or excess sebum, so it carries only a slight possibility of clogging. People who are prone to acne or breakouts usually tolerate it without issue.

As with any emulsifier, the finished formula matters. Heavy oils or waxes paired with C12-15 Alketh-12 could still feel occlusive, so overall product composition should guide your choice.

Summary

C12-15 Alketh-12 is an emulsifier that helps oil and water mix into smooth stable creams, lotions and cleansers. By turning oily alcohols into a water loving molecule, it lets formulas stay uniform, feel light and spread evenly so active ingredients can do their job. It is not a headline grabbing ingredient but a quiet workhorse found in many mainstream and budget friendly products because it is reliable, versatile and cost effective.

Current data show it is generally safe for all skin types with only rare reports of mild irritation or allergy. Still, skin is personal so it is wise to patch test any new product that contains C12-15 Alketh-12 before using it all over the face or body.

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