Ingredient review
Isosteareth-22
INCI: ISOSTEARETH-22
Isosteareth-22 is a gentle synthetic emulsifier that helps mix water and oil in creams and cleansers, with a low risk of irritation.
In plain English
Isosteareth-22 is a man-made ingredient that helps water and oil stay blended together in products like lotions and face washes. Without it, the oil and water would separate into layers. It's a type of surfactant, meaning it can also help lift dirt and oil from your skin so they rinse away easily. Because it's made from a fatty alcohol (isostearyl alcohol) combined with ethylene oxide, it's considered very gentle and unlikely to cause stinging or redness.
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
Isosteareth-22 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 Isosteareth-22.
- 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
Isosteareth-22 is a polyethylene glycol (PEG) ether of isostearyl alcohol. It belongs to the 'isosteareth' family, where the number 22 indicates the average length of the PEG chain. It is a white to off-white waxy solid at room temperature and is produced synthetically.
How it works
In a cosmetic formula, Isosteareth-22 sits at the boundary between oil and water droplets. Its water-loving (hydrophilic) PEG chain extends into water, while its oil-loving (lipophilic) isostearyl chain embeds in oil. This reduces surface tension and prevents the two phases from separating, creating a stable, smooth emulsion. In cleansers, it also helps surround and lift away oily debris and sunscreen from the skin.
Pros
Gentle on skin
Isosteareth-22 has a very low irritation and sensitization rate, making it suitable for sensitive skin types and daily use in leave-on products.
Effective emulsifier
It creates stable, smooth emulsions that prevent separation, ensuring your product stays consistent from first use to last.
Cons and cautions
Synthetic origin
It is not natural or plant-derived, which may be a drawback for consumers seeking 'clean' or minimalist ingredient lists.
Potential trace impurities
As an ethoxylated ingredient, it may contain trace amounts of 1,4-dioxane if not properly purified, though reputable manufacturers keep levels well below safety limits.
Best for
- People with normal to dry skin looking for a rich, stable moisturizer
- Anyone using water-resistant sunscreens or makeup who wants a gentle cleanser that removes them
Use caution if
- Those who strictly avoid all PEG compounds or synthetic ingredients
- Individuals with known sensitivity to ethoxylated ingredients (rare)
Usage tips
Safety summary
Isosteareth-22 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, but levels are tightly controlled by regulations and good manufacturing practices. Skin irritation and allergy are very rare.
Research notes
Safety assessments by the Cosmetic Ingredient Review (CIR) panel have concluded that isosteareth compounds are safe as used in cosmetics. Studies show low acute toxicity and no significant skin irritation or sensitization. There is limited specific research on Isosteareth-22 itself, but it is grouped with similar ethoxylated alcohols.
Common label clues
- Typical concentration
- 0.5% to 5%
- Regulatory status
- Approved for use in cosmetics in the US (FDA), EU (CosIng), and many other regions. The EU restricts 1,4-dioxane to a maximum of 10 ppm in finished products, which reputable manufacturers comply with.
- Common uses
- Cleansers, Moisturizers, Sunscreens, Makeup removers
- Environmental note
- Isosteareth-22 is not readily biodegradable and may persist in aquatic environments. Its production involves ethylene oxide, which is derived from fossil fuels.
Good to know
- The number '22' in Isosteareth-22 refers to the average number of ethylene oxide units, which affects its water solubility and emulsifying strength.
- It is often used in combination with other emulsifiers to achieve a specific texture or feel.
Common questions
What is Isosteareth-22 in beauty products?
Isosteareth-22 is a man-made ingredient that helps water and oil stay blended together in products like lotions and face washes. Without it, the oil and water would separate into layers. It's a type of surfactant, meaning it can also help lift dirt and oil from your skin so they rinse away easily. Because it's made from a fatty alcohol (isostearyl alcohol) combined with ethylene oxide, it's considered very gentle and unlikely to cause stinging or redness.
What does Isosteareth-22 do in a beauty product?
In a cosmetic formula, Isosteareth-22 sits at the boundary between oil and water droplets. Its water-loving (hydrophilic) PEG chain extends into water, while its oil-loving (lipophilic) isostearyl chain embeds in oil. This reduces surface tension and prevents the two phases from separating, creating a stable, smooth emulsion. In cleansers, it also helps surround and lift away oily debris and sunscreen from the skin.
Is Isosteareth-22 safe for most people?
Isosteareth-22 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, but levels are tightly controlled by regulations and good manufacturing practices. Skin irritation and allergy are very rare.
Who should be careful with Isosteareth-22?
Those who strictly avoid all PEG compounds or synthetic ingredients Individuals 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.