Ingredient review
Isopropylidenediphenol Bis-Hydroxypropyl PEG-180
INCI: ISOPROPYLIDENEDIPHENOL BISHYDROXYPROPYL PEG-180
A synthetic film-former that helps products spread smoothly and stay put, but its connection to bisphenol A raises caution for some users.
In plain English
This ingredient is a large molecule made by attaching a long chain of PEG (polyethylene glycol) to a modified version of bisphenol A. In cosmetics, it forms a thin, flexible film on skin or hair, helping makeup last longer and giving a smooth feel. The PEG part makes it water-soluble, so it rinses off easily. While the starting material is related to bisphenol A, the final molecule is much larger and less likely to be absorbed through skin. However, some people prefer to avoid any bisphenol-related ingredients due to potential concerns.
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
Isopropylidenediphenol Bis-Hydroxypropyl PEG-180 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 Isopropylidenediphenol Bis-Hydroxypropyl PEG-180.
- 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
A synthetic polymer created by reacting a bisphenol A derivative with propylene oxide and then attaching a long PEG chain (180 units). It is a clear to slightly hazy liquid or paste used to improve product texture and wear.
How it works
When applied, the PEG chains dissolve in water or other solvents, while the bisphenol core provides structure. As the product dries, the molecules link together to form a flexible film that holds pigments and other ingredients in place. This film is water-resistant but not waterproof, and it helps prevent smudging or fading.
Pros
Long-lasting wear
Helps makeup and mascara resist smudging and fading throughout the day without feeling stiff or heavy.
Smooth texture
Creates an even, silky feel on skin and hair, making application easier and more comfortable.
Cons and cautions
Bisphenol A connection
The ingredient is derived from bisphenol A, which has been linked to endocrine disruption in other uses. While the final polymer is much larger and less absorbable, some consumers prefer to avoid it entirely.
Limited safety data
There is little published research specifically on this polymer's effects on skin over long-term use, so its safety profile is not as well-established as simpler ingredients.
Best for
- People who want long-wearing makeup or mascara
- Those looking for a smooth, non-tacky finish in foundations
Use caution if
- Individuals with known sensitivity to bisphenol compounds
- Anyone seeking fully natural or bisphenol-free formulations
Usage tips
Safety summary
Generally considered safe for topical use at typical concentrations. The large molecular size limits skin absorption, reducing systemic exposure. However, the bisphenol A origin means some consumers and regulators remain cautious. Patch testing is recommended for sensitive individuals.
Research notes
Limited peer-reviewed studies exist specifically on this ingredient. Most safety assessments rely on analogy to other PEG polymers and bisphenol derivatives. The Cosmetic Ingredient Review (CIR) has not published a dedicated monograph on this compound, but similar PEG polymers are considered safe at low concentrations.
Common label clues
- Typical concentration
- 0.5% to 5%
- Regulatory status
- Approved for use in cosmetics in the EU, US, and many other regions. The EU CosIng database lists it as a film-forming agent with no specific restrictions, though bisphenol derivatives are under ongoing review.
- Common uses
- Foundations, Mascaras, Lip Products, Hair Styling Products
- Environmental note
- As a synthetic polymer, it may not be biodegradable. PEG-based ingredients can persist in water systems, so environmental impact is a consideration for eco-conscious consumers.
Good to know
- The 'PEG-180' part means the molecule has a very long polyethylene glycol chain, which makes it water-soluble and less likely to penetrate skin.
- This ingredient is not the same as bisphenol A itself; it is a modified, larger molecule designed for cosmetic use.
Common questions
What is Isopropylidenediphenol Bis-Hydroxypropyl PEG-180 in beauty products?
This ingredient is a large molecule made by attaching a long chain of PEG (polyethylene glycol) to a modified version of bisphenol A. In cosmetics, it forms a thin, flexible film on skin or hair, helping makeup last longer and giving a smooth feel. The PEG part makes it water-soluble, so it rinses off easily. While the starting material is related to bisphenol A, the final molecule is much larger and less likely to be absorbed through skin. However, some people prefer to avoid any bisphenol-related ingredients due to potential concerns.
What does Isopropylidenediphenol Bis-Hydroxypropyl PEG-180 do in a beauty product?
When applied, the PEG chains dissolve in water or other solvents, while the bisphenol core provides structure. As the product dries, the molecules link together to form a flexible film that holds pigments and other ingredients in place. This film is water-resistant but not waterproof, and it helps prevent smudging or fading.
Is Isopropylidenediphenol Bis-Hydroxypropyl PEG-180 safe for most people?
Generally considered safe for topical use at typical concentrations. The large molecular size limits skin absorption, reducing systemic exposure. However, the bisphenol A origin means some consumers and regulators remain cautious. Patch testing is recommended for sensitive individuals.
Who should be careful with Isopropylidenediphenol Bis-Hydroxypropyl PEG-180?
Individuals with known sensitivity to bisphenol compounds Anyone seeking fully natural or bisphenol-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.