Ingredient review

PEG-160 Sorbitan Triisostearate

INCI: PEG-160 Sorbitan Triisostearate

A gentle, large-molecule emulsifier that stabilizes oil-and-water blends without significant irritation or clogging concerns.

beautyskincareemulsifier

In plain English

PEG-160 Sorbitan Triisostearate is a semi-synthetic ingredient that helps mix oil and water in creams and lotions. The 'PEG-160' part means it has a long chain of ethylene glycol units, which makes it water-friendly and less likely to penetrate the skin. It's used to keep products smooth and stable, and it's generally considered very gentle.

Review score

Safety, usefulness, and evidence

3.8Good
3.8/ 5

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
semi synthetic
Evidence
moderate
Irritation
low
Clogging risk
low
How reviews are scored

Quick decision guide

Useful, but context matters

PEG-160 Sorbitan Triisostearate 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.

  1. Step 1Start with the score, then check the irritation and clogging risk before judging PEG-160 Sorbitan Triisostearate.
  2. Step 2Use the "Best for" and "Use caution if" sections to match the ingredient to your skin, not just to a marketing claim.
  3. 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

low

Less likely to sting, burn, or bother most users, though sensitive skin can still react.

Clogging risk

low

Less likely to feel heavy or contribute to clogged pores for most skin types.

Evidence level

moderate

There is useful support, but formula details and claim strength still matter.

What it is

A non-ionic surfactant and emulsifier made by attaching 160 units of polyethylene glycol (PEG) to sorbitan triisostearate, a derivative of sorbitol (a sugar alcohol) and isostearic acid (a fatty acid).

How it works

It reduces the surface tension between oil and water, allowing them to form a stable, uniform mixture. Because of its large molecular size, it stays on the skin's surface rather than absorbing deeply, making it a mild option for sensitive formulas.

Pros

Gentle on skin

Its large molecular size means it stays on the surface, reducing the chance of irritation or clogged pores.

Excellent stabilizer

It helps prevent creams and lotions from separating, ensuring a consistent texture and dose of active ingredients.

Cons and cautions

Synthetic origin

It is made from petrochemical-derived ethylene oxide, which may be a concern for those seeking natural or green beauty products.

Potential impurities

If not manufactured to high standards, PEG compounds can contain trace amounts of 1,4-dioxane, a possible carcinogen. However, reputable brands use purified grades.

Best for

  • People with normal to dry skin looking for a stable moisturizer
  • Those with sensitive skin who need a gentle emulsifier

Use caution if

  • Individuals who prefer completely natural or PEG-free formulations

Usage tips

Use in oil-in-water or water-in-oil emulsions at 1–5% of the formula.
Combine with co-emulsifiers like cetearyl alcohol for extra stability.
Store products containing this ingredient in a cool, dry place to maintain emulsion integrity.

Safety summary

PEG-160 Sorbitan Triisostearate is considered safe for cosmetic use at typical concentrations. Its large molecular size limits skin penetration, and it has a low irritation and comedogenic profile. The main concern is the potential for trace impurities in PEG manufacturing, which is minimized by using high-quality, purified ingredients.

Research notes

Safety assessments by the Cosmetic Ingredient Review (CIR) panel have found PEG derivatives safe when formulated to minimize impurities. Specific studies on PEG-160 Sorbitan Triisostearate are limited, but its structure and properties align with other well-studied PEG emulsifiers.

Common label clues

Typical concentration
0.5% to 5%
Regulatory status
Approved for use in cosmetics by the FDA (as part of generally recognized ingredients) and the EU CosIng database. No concentration restrictions are specified, but typical use is low.
Common uses
Moisturizers, Sunscreens, Makeup removers, Serums
Environmental note
PEG compounds can be slow to biodegrade in aquatic environments. However, this specific high-molecular-weight version is less likely to be absorbed by organisms.

Good to know

  • PEG-160 Sorbitan Triisostearate is often used in 'clean' beauty formulations because it is considered very mild.
  • It is not a preservative, so products still need a proper preservation system.

Common questions

What is PEG-160 Sorbitan Triisostearate in beauty products?

PEG-160 Sorbitan Triisostearate is a semi-synthetic ingredient that helps mix oil and water in creams and lotions. The 'PEG-160' part means it has a long chain of ethylene glycol units, which makes it water-friendly and less likely to penetrate the skin. It's used to keep products smooth and stable, and it's generally considered very gentle.

What does PEG-160 Sorbitan Triisostearate do in a beauty product?

It reduces the surface tension between oil and water, allowing them to form a stable, uniform mixture. Because of its large molecular size, it stays on the skin's surface rather than absorbing deeply, making it a mild option for sensitive formulas.

Is PEG-160 Sorbitan Triisostearate safe for most people?

PEG-160 Sorbitan Triisostearate is considered safe for cosmetic use at typical concentrations. Its large molecular size limits skin penetration, and it has a low irritation and comedogenic profile. The main concern is the potential for trace impurities in PEG manufacturing, which is minimized by using high-quality, purified ingredients.

Who should be careful with PEG-160 Sorbitan Triisostearate?

Individuals who prefer completely natural or PEG-free formulations

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.