C12-14 Sec-Pareth-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
Share:
Inside this article:

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 C12-14 Sec-Pareth-12?

C12-14 Sec-Pareth-12 is a man-made ingredient created by joining synthetic secondary fatty alcohols that have 12 to 14 carbon atoms with about 12 units of ethylene oxide. This reaction turns the oils into a water-friendly, nonionic surfactant that mixes easily with both water and oil. The fatty alcohol base can come from petroleum or plant sources but is always processed in a lab to give constant quality.

Surfactants like this began appearing in personal care products in the mid-1900s when chemists wanted gentler yet effective cleansers. Over time the balance of cleaning power and mildness made ethoxylated fatty alcohols a staple in modern formulas.

Manufacturing starts with refining the fatty alcohols, then treating them with ethylene oxide gas under heat and pressure. Careful control of temperature and the amount of gas added lets chemists “build” the chain to exactly 12 ethylene oxide units on average. The result is a clear to pale liquid that blends smoothly into water-based or oil-based mixtures.

You will often spot C12-14 Sec-Pareth-12 in facial cleansers, body washes, shampoos, conditioners, micellar waters, makeup removers, exfoliating scrubs, sheet masks, creams, lotions and lightweight serums where a stable emulsion and gentle cleansing action are needed.

C12-14 Sec-Pareth-12’s Cosmetic Benefits/Uses

This multitasking ingredient adds several useful traits to everyday beauty products:

  • Emulsion stabilising – Helps water and oil stay blended so creams and lotions keep a smooth, even texture throughout their shelf life
  • Cleansing – Lifts away dirt, oil and makeup without leaving the skin feeling stripped which is why it appears in gentle face and body washes
  • Emulsifying – Allows formulators to mix oil-based and water-based ingredients in the first place opening the door to lightweight milks, serums and sprays that feel pleasant on skin and hair

Who Can Use C12-14 Sec-Pareth-12

Because it is a mild nonionic surfactant, C12-14 Sec-Pareth-12 is generally suitable for normal, oily and combination skin and can even fit into many sensitive skin formulas when used at low levels. Extremely reactive or highly compromised skin may still experience irritation if the overall product is poorly balanced or heavily fragranced so those users should approach with a bit more caution.

The ingredient itself is synthesized from either petroleum-derived or plant-derived fatty alcohols and contains no animal material, making it appropriate for most vegan and vegetarian lifestyles; however conscientious shoppers may wish to confirm the alcohol source with the brand to be certain.

No evidence links topical C12-14 Sec-Pareth-12 to risks during pregnancy or while breastfeeding. It has a low systemic absorption profile and is not known to interfere with hormonal pathways. This is not medical advice; anyone who is pregnant or nursing should still run new skincare products by their physician to be safe.

C12-14 Sec-Pareth-12 does not increase photosensitivity so it will not make skin more prone to sunburn. As with any cleanser or emulsifier it should be followed by sunscreen in the daytime simply because a complete routine always includes UV protection.

Potential Side Effects/Adverse Reactions

Responses to topical C12-14 Sec-Pareth-12 vary from person to person. The points below outline potential side effects but these outcomes are uncommon when the ingredient is used correctly and at appropriate concentrations.

  • Skin irritation – Redness, itching or a burning sensation if the formula is too concentrated or left on the skin for prolonged periods
  • Eye irritation – Stinging or watering when high-foaming cleansers accidentally get into the eyes
  • Allergic contact dermatitis – Rare sensitisation presenting as rash or swelling in people with an allergy to ethoxylated surfactants
  • Dryness or tightness – Temporary depletion of skin lipids in very frequent users or in products with high surfactant levels
  • Possible trace impurities – Residual 1,4-dioxane may form during manufacturing though reputable brands keep it well below safety thresholds

If any irritation or adverse reaction occurs stop using the product and consult a qualified healthcare professional.

Comedogenic Rating

Rating: 1 out of 5. C12-14 Sec-Pareth-12 is highly water soluble and designed to rinse cleanly without leaving an oily film that could block pores. In most formulations it is present at low percentages and is often part of rinse-off products, which further reduces any chance of buildup. For these reasons it earns a very low clog-pore score.

Suitable for acne-prone or breakout-prone skin in the vast majority of cases.

Because it is an ethoxylated surfactant, any residual impurities are flushed away during manufacturing and final purification, keeping its surface residue minimal and further lowering comedogenic concern.

Summary

C12-14 Sec-Pareth-12 acts mainly as an emulsion stabiliser, cleanser and emulsifier. Its longish fatty alcohol backbone grabs oils while the attached ethylene oxide units attract water, allowing it to sit at the oil-water interface, keep formulas homogeneous and lift grime from skin and hair.

It shows up in many modern cleansers, lightweight creams and micellar waters but is not as famous as star ingredients like glycerin or hyaluronic acid, making it more of a quiet workhorse than a buzzword.

Current safety data call it low risk for irritation, sensitisation or systemic toxicity when used at normal cosmetic levels. Still, skin can be unpredictable so performing a small patch test with any new product that contains C12-14 Sec-Pareth-12 remains a smart habit.

Was this article helpful?
More from Glooshi:
ADVERTISEMENT
Get all our top headlines in beauty.
Delivered right to your inbox each week. Zero spam, all goodness, opt-out at anytime.
This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.
Send good feedback:

All feedback is greatly appreciated, anonymous, and will be used to improve the quality of our articles.

This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.
Send bad feedback:

All feedback is greatly appreciated, anonymous, and will be used to improve the quality of our articles.

This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.