Ingredient review
Steareth-30
INCI: STEARETH-30
Steareth-30 is a widely used emulsifier that helps create stable, creamy textures in skincare, with a low risk of irritation.
In plain English
Steareth-30 is a synthetic ingredient made from stearyl alcohol (a fatty alcohol from plant or petroleum sources) and ethylene oxide. In skincare, it acts like a bridge that allows oil and water to mix together, which is essential for making smooth lotions and creams. It also helps cleanse the skin by lifting dirt and oil. Because it's gentle, it's commonly used in products for sensitive skin.
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-30 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-30.
- 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-30 is a polyethylene glycol (PEG) ether of stearyl alcohol, containing an average of 30 ethylene oxide units. It belongs to the steareth family of emulsifiers and is produced through ethoxylation, a chemical process that makes the ingredient water-soluble.
How it works
Steareth-30 has both water-loving (hydrophilic) and oil-loving (lipophilic) parts. When added to a formula, it positions itself at the interface of oil and water droplets, reducing surface tension so they can blend into a stable emulsion. This prevents the product from separating and gives it a smooth, uniform texture.
Pros
Gentle emulsifier
Steareth-30 has a low irritation risk and is often used in formulations for sensitive skin, making it a safe choice for daily moisturizers and cleansers.
Improves product texture
It helps create a smooth, non-greasy feel that spreads easily on the skin, enhancing the user experience of creams and lotions.
Cons and cautions
Potential impurity concern
The ethoxylation process can produce trace amounts of 1,4-dioxane, a possible carcinogen. However, reputable manufacturers purify the ingredient to very low levels that are considered safe by regulators.
Synthetic origin
Steareth-30 is not naturally derived, which may be a drawback for those seeking fully natural or organic skincare products.
Best for
- People with normal to dry skin looking for a stable, gentle moisturizer
- Those who prefer products with a rich, creamy texture
Use caution if
- Individuals with known sensitivities to PEG compounds or ethoxylated ingredients
Usage tips
Safety summary
Steareth-30 is considered safe for use in cosmetics at typical concentrations. The main safety concern is the potential presence of 1,4-dioxane, a byproduct of ethoxylation. Regulatory bodies like the CIR and EU SCCS have set limits for this impurity, and most reputable manufacturers ensure levels are below 10 ppm. Overall, the risk to consumers is very low.
Research notes
Studies on steareth compounds focus on their safety as emulsifiers. The CIR expert panel reviewed steareth-2 through steareth-100 and concluded they are safe when formulated to minimize 1,4-dioxane. No significant skin irritation or sensitization was observed in clinical tests at typical use levels.
Common label clues
- Typical concentration
- 1% to 5%
- Regulatory status
- Approved for use in cosmetics by the FDA and the European Commission. The Cosmetic Ingredient Review (CIR) panel has deemed steareth ingredients safe as used in cosmetics, with the caveat that impurities like 1,4-dioxane should be minimized.
- Common uses
- Moisturizers, Cleansers, Lotions, Creams
- Environmental note
- Steareth-30 is not readily biodegradable in all environments due to its synthetic PEG structure, which can persist in water systems. However, it is not classified as a bioaccumulative toxin.
Good to know
- Steareth-30 is often used alongside fatty alcohols like cetearyl alcohol to boost emulsion stability.
- The number '30' refers to the average number of ethylene oxide units, which affects its water solubility and performance.
Common questions
What is Steareth-30 in beauty products?
Steareth-30 is a synthetic ingredient made from stearyl alcohol (a fatty alcohol from plant or petroleum sources) and ethylene oxide. In skincare, it acts like a bridge that allows oil and water to mix together, which is essential for making smooth lotions and creams. It also helps cleanse the skin by lifting dirt and oil. Because it's gentle, it's commonly used in products for sensitive skin.
What does Steareth-30 do in a beauty product?
Steareth-30 has both water-loving (hydrophilic) and oil-loving (lipophilic) parts. When added to a formula, it positions itself at the interface of oil and water droplets, reducing surface tension so they can blend into a stable emulsion. This prevents the product from separating and gives it a smooth, uniform texture.
Is Steareth-30 safe for most people?
Steareth-30 is considered safe for use in cosmetics at typical concentrations. The main safety concern is the potential presence of 1,4-dioxane, a byproduct of ethoxylation. Regulatory bodies like the CIR and EU SCCS have set limits for this impurity, and most reputable manufacturers ensure levels are below 10 ppm. Overall, the risk to consumers is very low.
Who should be careful with Steareth-30?
Individuals with known sensitivities to PEG compounds or ethoxylated 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.