C12-16 Alketh-7: 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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We verify all information on this page using publicly available nomenclature standards from The Personal Care Products Council (PCPC), the European Commission's CosIng database and documentation provided directly by ingredient manufacturers. Our analysis is based on technical data from these sources to ensure accuracy and reliability.

What Is C12-16 Alketh-7?

C12-16 Alketh-7 is a man-made ingredient created by reacting synthetic fatty alcohols that have carbon chain lengths between 12 and 16 with ethylene oxide. On average seven units of ethylene oxide attach to each fatty alcohol molecule, which is why the name ends in “-7.” The result is a waxy, water-soluble substance that helps water mix with oil. Its roots trace back to the mid-20th century when chemists were looking for safer, more efficient alternatives to natural soaps for use in personal care. As improvements in surfactant chemistry advanced, this particular blend of alcohols and ethylene oxide gained favor for its reliable performance and mild skin feel.

Manufacturing begins with petroleum-derived or plant-derived fatty alcohols. These alcohols are purified then reacted with ethylene oxide gas inside pressurized reactors. Controlling temperature, pressure and reaction time lets chemists dial in the exact average of seven ethylene oxide units. After the reaction is complete, the mixture is neutralized, filtered and tested for purity before it is supplied to cosmetic manufacturers.

You will most often see C12-16 Alketh-7 in products that need to keep oily and watery parts from separating. It appears in facial cleansers, lightweight lotions, body washes, cream masks, hair conditioners, makeup removers and some anti-aging serums. Its versatility and mildness make it a go-to helper ingredient across both rinse-off and leave-on formulas.

C12-16 Alketh-7’s Cosmetic Benefits/Uses

This ingredient plays a single but important role in cosmetic science.

As an emulsifying agent C12-16 Alketh-7 binds oil and water into a stable, uniform mixture. That stability keeps creams from separating during storage, gives lotions a smooth texture, helps cleansers rinse cleanly and allows active ingredients to be delivered evenly onto the skin or hair.

Who Can Use C12-16 Alketh-7

C12-16 Alketh-7 is generally considered suitable for all skin types. Its mild nature means it works well for normal, dry or oily skin without leaving a heavy residue, while its low potential to clog pores makes it acceptable for combination and acne-prone skin. Extremely sensitive or reactive skin may still experience issues if it is intolerant to polyethylene glycol (PEG) ingredients, so monitoring for irritation is wise.

The ingredient is produced from synthetic or plant-derived fatty alcohols and contains no animal-sourced materials, so it aligns with vegan and vegetarian preferences.

No specific safety flags have been raised for women who are pregnant or breastfeeding when C12-16 Alketh-7 is used at customary cosmetic levels. That said, this is not medical advice and anyone who is pregnant or nursing should have a doctor review any skincare products they plan to use.

C12-16 Alketh-7 does not make skin more sensitive to sunlight, and it has no known incompatibilities with common active ingredients at normal use levels.

Potential Side Effects/Adverse Reactions

Reactions to topical C12-16 Alketh-7 differ from person to person. The points below outline possible side effects, but most users will not experience them when the ingredient is formulated and used correctly.

  • Mild skin stinging or redness
  • Allergic contact dermatitis in individuals sensitive to PEG compounds
  • Eye irritation if the product accidentally gets into the eyes
  • Dryness or tightness if used in high concentrations or in very frequent cleansing routines

If any of these effects occur stop using the product and seek advice from a healthcare professional.

Comedogenic Rating

Rating: 1 / 5

C12-16 Alketh-7 is a water-soluble emulsifier that does not sit heavily on skin or form an occlusive film, so it has little tendency to block pores. Its fatty alcohol portion is balanced by seven ethylene oxide units that boost rinse-off and reduce residue, keeping the overall clogging potential low. A rating of 1 reflects this minimal risk while still acknowledging that any ingredient can cause issues in very sensitive or oily skin under certain conditions.

Suitable for acne-prone or breakout-prone skin in most formulations.

Because it often appears at low levels alongside many other ingredients, the finished product’s overall comedogenicity will depend more on the full formula than on C12-16 Alketh-7 itself.

Summary

C12-16 Alketh-7 is primarily an emulsifier that keeps oil and water blended, stabilises textures, improves spreadability and helps cleansing products rinse clean. It achieves these tasks by pairing a short fatty alcohol chain that grabs onto oils with multiple ethylene oxide units that love water, allowing it to bridge the two phases effectively.

The ingredient is a quiet workhorse rather than a headline grabber. It is widely used behind the scenes in cleansers, lotions and hair care but rarely advertised on front labels, mainly because it performs a supporting role rather than delivering an active skin benefit.

Current data and industry experience point to a strong safety profile at typical cosmetic concentrations, with low irritation and very low comedogenic risk. As with any new product though, it is smart to patch test to ensure personal compatibility.

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