C30-50 Pareth-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 C30-50 Pareth-3?

C30-50 Pareth-3 is a non-ionic surfactant made by attaching an average of three ethylene oxide units to very long chain fatty alcohols that contain 30 to 50 carbon atoms. The fatty alcohols can come from natural plant oils such as coconut or palm or from petroleum-based sources. This blend of a long oily part and a short water-loving part gives the ingredient its surface-active power.

Non-ionic surfactants like C30-50 Pareth-3 gained popularity in the late 20th century when formulators looked for milder alternatives to traditional soaps. Ethoxylation technology allowed chemists to fine-tune cleansing strength and skin feel, and this specific chain length offered rich, creamy textures without heavy residue.

Manufacturing starts with purified C30-C50 fatty alcohols. These alcohols are reacted with controlled amounts of ethylene oxide under heat and pressure. The result is a thick paste or wax that is then cooled, flaked or melted and blended into cosmetic bases.

You will most often find C30-50 Pareth-3 in rinse-off facial cleansers, cream washes, body washes, emulsifying lotions, masks, hair conditioners, makeup removers and anti-aging creams where a gentle yet effective cleanser or stabilizer is needed.

C30-50 Pareth-3’s Cosmetic Benefits/Uses

Below are the key roles C30-50 Pareth-3 plays in beauty products

  • Cleansing: Its surfactant nature lifts dirt, oil and makeup from skin and hair then helps them rinse away with water for a fresh, clean feel without stripping natural moisture.
  • Emulsifying: It keeps water and oil phases mixed, giving creams and lotions a smooth, uniform texture and preventing separation during storage and use.

Who Can Use C30-50 Pareth-3

C30-50 Pareth-3 is generally well tolerated by all skin types. Its non-ionic structure gives it a mild touch that suits normal, dry, oily and combination skin without leaving a tight or greasy after-feel. Sensitive skin can usually handle it too because it lacks the harsh charge found in some sulfate surfactants, though very reactive skin should still watch for any personal triggers.

The ingredient itself is synthetic but the fatty alcohol portion may be sourced from either plants or petroleum. It is not typically derived from animals so formulas that use plant or petroleum sources and carry a vegan label are suitable for vegans and vegetarians. If strict plant origin matters, look for products that state “plant derived” or carry a credible vegan certification.

C30-50 Pareth-3 has no known issues for women who are pregnant or breastfeeding when used topically in cosmetics. It is considered low risk and does not penetrate deeply into skin. This is not medical advice and anyone who is pregnant or nursing should still have a doctor review their full skincare routine to be safe.

The ingredient does not cause photosensitivity and will not make skin more prone to sunburn. It is also fragrance free by nature and contains no known hormone-disrupting components.

Potential Side Effects/Adverse Reactions

Reactions to topical C30-50 Pareth-3 vary from person to person. The points below list potential side effects yet these outcomes are uncommon when the ingredient is used correctly by the manufacturer.

  • Mild skin irritation in extremely sensitive users, often felt as stinging or itching that stops once the product is rinsed away
  • in rare cases of true allergy to ethoxylated fatty alcohols
  • if a cleanser containing the ingredient gets into the eyes
  • when used in very high concentrations or left on the skin too long in rinse-off products
  • for individuals prone to clogged pores if the product is a leave-on formula with high levels of the ingredient

If you experience any of these effects stop using the product and consult a healthcare professional

Comedogenic Rating

Rating: 1 / 5

The large ethoxylated chain makes C30-50 Pareth-3 too bulky to slip easily into pores and the surfactant nature helps lift oils rather than sit on skin. While the long fatty alcohol backbone adds richness, the low average use level in most formulas keeps residue minimal, placing it at the lower end of the scale.

Suitable for acne-prone skin in most rinse-off and well-balanced leave-on products.

Formulas that pair it with heavy occlusives or waxes could raise the clogging risk slightly so the full ingredient list still matters.

Summary

C30-50 Pareth-3 works as a gentle cleanser and an emulsifier. Its water-loving ethoxy groups surround dirt and oil so they can be rinsed away, while its long oily tail anchors water and oil phases together for stable, smooth textures.

It appears in a modest number of cleansers, lotions and masks, valued by formulators who want a mild non-ionic option though it is not as ubiquitous as shorter-chain surfactants.

Safety data show a low irritation profile and negligible absorption, making it broadly acceptable for everyday use. As with any new product a quick patch test is wise to rule out personal sensitivities.

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