Ingredient review
Steareth-16
INCI: STEARETH-16
Steareth-16 is a synthetic emulsifier that helps blend oil and water in creams and lotions, with a low risk of irritation for most skin types.
In plain English
Steareth-16 is a man-made ingredient that helps oil and water mix together in skincare products like moisturizers and cleansers. It is part of a family of ingredients called ethoxylated alcohols, which are created by adding ethylene oxide to stearyl alcohol (a fatty alcohol from plants or petroleum). This process makes the ingredient water-friendly, so it can stabilize creamy formulas and help them spread smoothly on your skin. While generally considered safe, some people prefer to avoid ethoxylated ingredients due to concerns about trace impurities formed during manufacturing.
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-16 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-16.
- 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-16 is a synthetic emulsifier derived from stearyl alcohol (a fatty alcohol) through a process called ethoxylation, where 16 units of ethylene oxide are added. It belongs to the Steareth family of ingredients, which are commonly used in cosmetics to stabilize oil-in-water emulsions.
How it works
Steareth-16 works by reducing the surface tension between oil and water, allowing them to blend into a stable, uniform cream or lotion. Its water-loving (hydrophilic) end dissolves in water, while its oil-loving (lipophilic) end dissolves in oil, creating a bridge that prevents the two phases from separating. This results in a smooth, consistent texture that feels pleasant on the skin.
Pros
Effective emulsifier
Steareth-16 reliably blends oil and water, giving creams and lotions a smooth, uniform texture that feels nice on the skin.
Low irritation risk
It has a low irritation and comedogenic rating, making it suitable for most skin types, including sensitive skin, when used at typical concentrations.
Cons and cautions
Potential 1,4-dioxane contamination
As an ethoxylated ingredient, Steareth-16 may contain trace amounts of 1,4-dioxane, a byproduct that is considered a possible human carcinogen. Reputable manufacturers purify to remove it, but it remains a concern for some.
Synthetic origin
It is a man-made ingredient, which may not align with preferences for natural or minimally processed skincare, especially in clean beauty routines.
Best for
- People with normal to dry skin looking for stable, creamy moisturizers
- Those who tolerate synthetic emulsifiers well and want affordable, effective products
Use caution if
- Individuals with known sensitivities to ethoxylated ingredients
- Those strictly avoiding any synthetic or potentially contaminated ingredients
Usage tips
Safety summary
Steareth-16 is considered safe for use in cosmetics at typical concentrations, with low irritation and comedogenic potential. The main safety concern is the potential presence of 1,4-dioxane, a byproduct of ethoxylation. Reputable manufacturers use purification steps to reduce this impurity to trace levels, and regulatory bodies consider it safe when properly processed.
Research notes
Research on Steareth-16 specifically is limited, but the broader class of ethoxylated alcohols has been reviewed by the Cosmetic Ingredient Review (CIR) panel, which found them safe as used in cosmetics. Studies indicate low acute toxicity and skin irritation potential. Concerns about 1,4-dioxane are based on animal studies showing carcinogenicity at high doses, but human exposure from cosmetics is very low.
Common label clues
- Typical concentration
- 0.5% to 5%
- Regulatory status
- Approved for use in cosmetics by the U.S. FDA and the European Commission, with concentration limits generally not specified. The Cosmetic Ingredient Review (CIR) panel has reviewed similar ethoxylated alcohols and found them safe as used, provided impurities are minimized.
- Common uses
- Moisturizers, Cleansers, Lotions, Creams
- Environmental note
- Steareth-16 is synthetic and not readily biodegradable, which may be a concern for environmentally conscious consumers. Its production involves ethylene oxide, a chemical that requires careful handling.
Good to know
- Steareth-16 is often used alongside other emulsifiers to improve stability.
- The number '16' refers to the average number of ethylene oxide units, which affects how water-friendly the ingredient is.
Common questions
What is Steareth-16 in beauty products?
Steareth-16 is a man-made ingredient that helps oil and water mix together in skincare products like moisturizers and cleansers. It is part of a family of ingredients called ethoxylated alcohols, which are created by adding ethylene oxide to stearyl alcohol (a fatty alcohol from plants or petroleum). This process makes the ingredient water-friendly, so it can stabilize creamy formulas and help them spread smoothly on your skin. While generally considered safe, some people prefer to avoid ethoxylated ingredients due to concerns about trace impurities formed during manufacturing.
What does Steareth-16 do in a beauty product?
Steareth-16 works by reducing the surface tension between oil and water, allowing them to blend into a stable, uniform cream or lotion. Its water-loving (hydrophilic) end dissolves in water, while its oil-loving (lipophilic) end dissolves in oil, creating a bridge that prevents the two phases from separating. This results in a smooth, consistent texture that feels pleasant on the skin.
Is Steareth-16 safe for most people?
Steareth-16 is considered safe for use in cosmetics at typical concentrations, with low irritation and comedogenic potential. The main safety concern is the potential presence of 1,4-dioxane, a byproduct of ethoxylation. Reputable manufacturers use purification steps to reduce this impurity to trace levels, and regulatory bodies consider it safe when properly processed.
Who should be careful with Steareth-16?
Individuals with known sensitivities to ethoxylated ingredients Those strictly avoiding any synthetic or potentially contaminated ingredients
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.