What Is Sodium Butoxynol-12 Sulfate?
Sodium Butoxynol-12 Sulfate is a synthetic surfactant derived from ethoxylated butylphenol that has been neutralized with sulfuric acid and converted to its sodium salt. Chemically it belongs to the family of alkylphenol ethoxylate sulfates, meaning it carries a water-loving sulfate group on one end and an oil-loving butylphenol chain on the other. This split personality lets it mingle with both oil and water, a trait that makes it valuable in personal care formulas.
The ingredient appeared in the cosmetics industry in the late 1970s when formulators were searching for milder, more versatile detergents than traditional soaps. By attaching multiple ethoxy units (the “-12” reflects the average number of these units) to butylphenol, chemists created a molecule that could clean effectively yet feel gentle on skin. Sulfation and neutralization turned the molecule into a stable, water-soluble powder or paste that dissolves quickly in production tanks.
Manufacturing starts with petrochemical or plant-based phenol, which is alkylated with butylene to produce butylphenol. Ethylene oxide gas is then added in controlled steps, tacking on about a dozen ethoxy groups. The resulting butoxynol-12 is treated with sulfur trioxide to form a sulfate ester, and finally neutralized with sodium hydroxide to yield Sodium Butoxynol-12 Sulfate. Quality control checks ensure low residual impurities and a narrow range of ethoxy units for consistent performance.
You will most often see this surfactant in facial cleansers, micellar waters, clarifying shampoos, body washes, exfoliating masks, liquid hand soaps and occasionally in lightweight moisturizers or serums where a touch of emulsifying power is needed to keep oil and water phases blended.
Sodium Butoxynol-12 Sulfate’s Cosmetic Benefits/Uses
This ingredient earns its spot on an ingredient list because it performs two key jobs that improve how a product works and feels.
- Cleansing: The molecule loosens dirt, makeup and excess sebum then lifts them away when rinsed with water. Its ethoxy chain softens the detergent action, helping reduce the tight or squeaky sensation that harsher cleansers can leave behind.
- Emulsifying: By positioning its oil-friendly end in oils and its water-friendly sulfate in the aqueous phase it keeps emulsions stable. This prevents creams, lotions and cleansing oils from separating on the shelf, ensuring an even dose of active ingredients with every use.
Who Can Use Sodium Butoxynol-12 Sulfate
Most skin types can tolerate Sodium Butoxynol-12 Sulfate when it is used at the low levels common in finished products. Normal, oily and combination skin usually benefit from its effective yet mild cleansing action. Acne-prone skin can also use it since the ingredient does not clog pores. Very dry or highly sensitive skin might feel a bit tight or experience mild irritation if the formula contains a high percentage of this surfactant, so those users should look for products blended with extra moisturizers or humectants.
The compound is produced from petrochemical or plant-based feedstocks with no animal-derived inputs, so it is considered suitable for both vegans and vegetarians. As always, cruelty-free status depends on the brand’s overall testing policies, not the ingredient itself.
Sodium Butoxynol-12 Sulfate is regarded as low risk for pregnant or breastfeeding women because it stays mainly on the surface of the skin and is rinsed away. This is not medical advice and anyone who is expecting or nursing should clear any new skincare product with their doctor just to be safe.
The ingredient does not increase photosensitivity, so it will not make skin more prone to sunburn. It is also compatible with most other common cosmetic ingredients, including acids, retinoids and botanical extracts.
Potential Side Effects/Adverse Reactions
Reactions to topical Sodium Butoxynol-12 Sulfate vary from person to person. The following is a list of potential side effects only; most people will not experience them when the ingredient is used correctly in a well-formulated product.
- Dryness or tightness, especially for very dry skin types
- Mild stinging or redness on sensitive or compromised skin
- Allergic contact dermatitis in individuals with a specific surfactant allergy
- Eye irritation if the product accidentally enters the eyes
- Increased penetration of other actives, which can amplify their own irritation potential
If any of these effects occur discontinue use and consult a healthcare professional or dermatologist.
Comedogenic Rating
Rating: 1 out of 5. Sodium Butoxynol-12 Sulfate is a water-soluble surfactant that rinses off easily so it tends not to linger in pores and mix with sebum. Its large, charged sulfate head keeps it from nesting inside follicles, which is why it earns a very low score. People who are prone to acne or breakouts can generally use products containing this ingredient without added risk. If a flare-up does appear it is usually due to other richer ingredients in the formula, not this cleanser.
Summary
Sodium Butoxynol-12 Sulfate works mainly as a cleanser and emulsifier. Its oil-loving tail grabs onto dirt, makeup and excess sebum while its water-loving sulfate head lets all that gunk rinse away. The same dual nature also keeps oils and water blended so lotions and washes stay smooth and uniform.
It is not the hottest name in skincare because many brands lean on more familiar surfactants like Sodium Laureth Sulfate, yet it still shows up in niche cleansers and micellar waters where a gentle but effective wash is needed. Safety reviews rate it low irritation when used at the small percentages typical in cosmetics. As with any new product a quick patch test on a small area of skin is a smart step before full use, especially if you have very sensitive or reactive skin.