Ingredient review
Steareth-12
INCI: STEARETH-12
A reliable synthetic emulsifier that helps mix water and oil in formulas, generally well-tolerated but may be too heavy for very oily skin.
In plain English
Steareth-12 is a man-made ingredient that helps water and oil stay mixed together in products like lotions and cleansers. It is part of a family of ingredients called ethoxylated alcohols, which are made by adding ethylene oxide to stearyl alcohol (a fatty alcohol from plants or petroleum). In your skincare, it helps create a smooth, creamy texture and makes it easier to rinse off dirt and oil. While it is generally safe and mild, some people with very sensitive or acne-prone skin may find it slightly heavy or potentially irritating if used in high amounts.
Review score
Safety, usefulness, and evidence
Potentially useful with some tradeoffs
The evidence base is useful, but some claims depend heavily on the formula.
Risk flags are low for most users, though the finished product can still irritate.
- Source
- synthetic
- Evidence
- moderate
- Irritation
- low
- Clogging risk
- low
Quick decision guide
Useful, but context matters
Steareth-12 is generally a lower-concern ingredient when the full formula suits your skin.
Plain-English read
Treat this as a practical screening step before you compare products that contain this ingredient.
- Step 1Start with the score, then check the irritation and clogging risk before judging Steareth-12.
- Step 2Use the "Best for" and "Use caution if" sections to match the ingredient to your skin, not just to a marketing claim.
- Step 3If a product stings, breaks you out, or worsens irritation, judge the finished formula and stop using it even if the ingredient scores well.
Score terms in plain English
Irritation risk
lowLess likely to sting, burn, or bother most users, though sensitive skin can still react.
Clogging risk
lowLess likely to feel heavy or contribute to clogged pores for most skin types.
Evidence level
moderateThere is useful support, but formula details and claim strength still matter.
What it is
Steareth-12 is a synthetic emulsifier derived from stearyl alcohol (a fatty alcohol) and ethylene oxide. It belongs to the steareth family, where the number (12) indicates the average number of ethylene oxide units. It is a waxy solid at room temperature and is used to stabilize oil-in-water emulsions.
How it works
Steareth-12 works by reducing the surface tension between oil and water, allowing them to blend into a stable emulsion. Its hydrophilic (water-loving) head and lipophilic (oil-loving) tail enable it to surround oil droplets and suspend them in water, creating a uniform, creamy product. It also helps cleanse by trapping dirt and oil so they can be rinsed away.
Pros
Effective emulsifier
Steareth-12 reliably blends oil and water, giving lotions and creams a smooth, uniform texture that doesn't separate over time.
Mild cleansing aid
It helps lift dirt and oil from skin without being overly stripping, making it suitable for gentle cleansers and makeup removers.
Cons and cautions
Potential heaviness
For those with very oily or acne-prone skin, Steareth-12 may feel slightly heavy or contribute to clogged pores, especially in high concentrations.
Ethoxylation concerns
The manufacturing process can create trace amounts of 1,4-dioxane, a possible carcinogen. However, reputable brands purify their ingredients to keep levels well below safety limits.
Best for
- People with normal to dry skin looking for a reliable, gentle emulsifier in moisturizers
- Those who prefer stable, well-mixed formulas without separation
Use caution if
- Individuals with very oily or acne-prone skin who may find it too heavy or potentially clogging
- Those with known sensitivity to ethoxylated ingredients (rare)
Usage tips
Safety summary
Steareth-12 is considered safe for use in cosmetics at typical concentrations. The main safety consideration is the potential for trace 1,4-dioxane contamination, but regulatory limits and purification methods keep this risk very low. It has low irritation and comedogenic potential for most skin types.
Research notes
Research on Steareth-12 is limited but consistent with other ethoxylated alcohols. Studies show it is a mild emulsifier with low acute toxicity and skin irritation. The Cosmetic Ingredient Review (CIR) panel has reviewed similar steareth ingredients and found them safe as used, with the caveat that 1,4-dioxane should be minimized.
Common label clues
- Typical concentration
- 0.5% to 5%
- Regulatory status
- Approved for use in cosmetics by the FDA and the European Commission, with no specific concentration restrictions. Manufacturers are expected to keep 1,4-dioxane levels below 10 ppm (parts per million) as a good manufacturing practice.
- Common uses
- Cleansers, Moisturizers, Shampoos, Conditioners
- Environmental note
- Steareth-12 is synthetic and not readily biodegradable in all conditions. However, it is not considered a major environmental concern at typical usage levels.
Good to know
- Steareth-12 is often used alongside other emulsifiers to create a stable, luxurious feel.
- The number 12 refers to the average ethylene oxide chain length, which affects how water- or oil-loving the ingredient is.
Common questions
What is Steareth-12 in beauty products?
Steareth-12 is a man-made ingredient that helps water and oil stay mixed together in products like lotions and cleansers. It is part of a family of ingredients called ethoxylated alcohols, which are made by adding ethylene oxide to stearyl alcohol (a fatty alcohol from plants or petroleum). In your skincare, it helps create a smooth, creamy texture and makes it easier to rinse off dirt and oil. While it is generally safe and mild, some people with very sensitive or acne-prone skin may find it slightly heavy or potentially irritating if used in high amounts.
What does Steareth-12 do in a beauty product?
Steareth-12 works by reducing the surface tension between oil and water, allowing them to blend into a stable emulsion. Its hydrophilic (water-loving) head and lipophilic (oil-loving) tail enable it to surround oil droplets and suspend them in water, creating a uniform, creamy product. It also helps cleanse by trapping dirt and oil so they can be rinsed away.
Is Steareth-12 safe for most people?
Steareth-12 is considered safe for use in cosmetics at typical concentrations. The main safety consideration is the potential for trace 1,4-dioxane contamination, but regulatory limits and purification methods keep this risk very low. It has low irritation and comedogenic potential for most skin types.
Who should be careful with Steareth-12?
Individuals with very oily or acne-prone skin who may find it too heavy or potentially clogging Those with known sensitivity to ethoxylated ingredients (rare)
Research sources
Ingredient reviews are educational and are not medical advice. Patch test new products and ask a licensed clinician about persistent irritation, allergies, pregnancy-specific questions, or diagnosed skin conditions.