Sodium Octoxynol-2 Ethane Sulfonate: 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 30, 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 Sodium Octoxynol-2 Ethane Sulfonate?

Sodium Octoxynol-2 Ethane Sulfonate is a synthetic ingredient made by attaching short chains of ethoxy units to an octylphenol backbone then finishing the molecule with a sulfonate group that is neutralized with sodium. The result is a water-soluble compound that loves both oil and water, a trait that makes it valuable in skin care.

The octylphenol part of the molecule comes from petrochemical streams while the ethoxy chains are added through a controlled reaction with ethylene oxide. The final sulfonation step, carried out with sulfur trioxide or chlorosulfonic acid, gives the ingredient its good foaming and dispersing powers. Once neutralized with sodium hydroxide the finished powder or liquid is ready for cosmetic labs.

Materials like this entered personal care formulas in the mid-20th century when chemists searched for gentler alternatives to traditional soap. Over time Sodium Octoxynol-2 Ethane Sulfonate earned a place in everyday items thanks to its mildness and versatility.

You will most often spot it in facial cleansers, micellar waters, exfoliating masks, makeup removers, body washes, light lotions and even some hair care rinses where a soft yet effective cleansing boost is needed.

Sodium Octoxynol-2 Ethane Sulfonate’s Cosmetic Benefits/Uses

In formulas this ingredient plays more than one helpful role:

  • Cleansing: Acts as a surfactant that lifts dirt, oil and makeup from the skin or hair allowing them to be rinsed away without harsh scrubbing. Its balanced nature helps keep the cleansing action effective yet gentle.
  • Emulsifying: Helps mix oil and water so creams, lotions and cleansers stay smooth and uniform. A stable emulsion means the product feels consistent, spreads easily and delivers its active ingredients evenly each time you use it.

Who Can Use Sodium Octoxynol-2 Ethane Sulfonate

This mild surfactant suits most skin types including normal, oily and combination skin. Dry or highly sensitive skin can generally tolerate it in low to moderate amounts but very delicate or compromised skin may feel a bit tight if the formula contains a high percentage of surfactants overall.

The ingredient is fully synthetic and sourced from petrochemicals so it contains no animal by-products making it acceptable for both vegetarians and vegans.

Current safety data does not flag Sodium Octoxynol-2 Ethane Sulfonate as a concern for women who are pregnant or breastfeeding. That said this is not medical advice and anyone expecting or nursing should run any skincare routine past a qualified healthcare professional to be sure it aligns with their individual needs.

It is not known to trigger photosensitivity so using products that contain it will not make skin more prone to sunburn. Regular sun protection is still essential for overall skin health.

Potential Side Effects/Adverse Reactions

Reactions to topical Sodium Octoxynol-2 Ethane Sulfonate differ from person to person. The points below outline potential side effects yet most users experience none of these issues when the ingredient is properly formulated in a finished product.

  • Mild skin irritation such as stinging or burning, especially on very sensitive areas
  • Temporary redness or flushing after use
  • Dryness or tightness if the rest of the formula lacks replenishing ingredients
  • Allergic contact dermatitis in individuals already sensitized to ethoxylated surfactants
  • Eye irritation if the product accidentally gets into the eyes

If you notice persistent irritation or any unexpected reaction discontinue use and seek guidance from a healthcare professional.

Comedogenic Rating

Rating: 0 / 5

Sodium Octoxynol-2 Ethane Sulfonate is highly water-soluble and designed to rinse off completely, so it does not linger in pores or contribute to the buildup of oil and dead skin that can form comedones. It functions mainly at the surface as a cleanser and emulsifier and is not an occlusive ingredient. Because of this, it is considered non-comedogenic and is generally suitable for those prone to acne or breakouts.

Some leave-on products may include it at very low levels for emulsion stability; even then its quick dispersal in water-based formulas keeps the risk of pore blockage negligible.

Summary

Sodium Octoxynol-2 Ethane Sulfonate cleans, emulsifies and boosts mild foam by using its oil-loving octylphenol tail and water-loving sulfonate head to bridge the two phases. This dual nature lets it lift grime, blend oils into watery bases and keep lotions uniform so every pump or swipe feels the same.

While it is a workhorse in lab benches it is not the most talked-about name on ingredient lists, often playing a behind-the-scenes role in facial cleansers, micellar waters and lightweight rinses that aim for gentle but effective cleansing.

Current research shows it is low risk for irritation when formulated well and it carries no major toxicity flags. Still, skin is personal so it is wise to patch test any new product containing this surfactant before fully incorporating it into your routine.

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