What Is Polyurethane-11?
Polyurethane-11 is a man-made polymer created by linking together building blocks such as adipic acid, 1,4-butanediol, isophthalic acid, methylene bis(4-cyclohexylisocyanate), neopentyl glycol and trimethylolpropane. When these components react they form long flexible chains that dry into a thin clear film on the skin. Polyurethane materials first took off in the 1940s as substitutes for rubber but formulators soon noticed their excellent film-forming ability. By the late 20th century cosmetic chemists began tailoring lighter versions like Polyurethane-11 to sit comfortably on skin and hair.
The manufacturing process starts with carefully measured batches of the acids, diols and isocyanate. Under controlled heat and vacuum they react in stages until the desired molecular weight is reached. The finished resin is then purified, ground into a fine powder or dispersed in water or alcohol to suit different product types.
Today you will spot Polyurethane-11 in long-wear makeup such as foundations, eyeliners and mascaras, transfer-resistant lipsticks, peel-off masks, sunscreens, hair styling sprays and even some lightweight moisturizers where a breathable film is helpful.
Polyurethane-11’s Cosmetic Benefits/Uses
Formulators like Polyurethane-11 because it gives products staying power without a heavy feel.
Its single function is film forming, meaning it dries into a flexible layer that locks pigments in place, improves water resistance, minimizes smudging and helps active ingredients cling to skin or hair for longer performance.
Who Can Use Polyurethane-11
Because Polyurethane-11 forms a light breathable film it suits most skin types including oily, combination and normal skin. Dry or mature skin can also tolerate it since it does not draw moisture away although pairing it with a hydrating base is wise. People with very sensitive or eczema-prone skin should watch for any tightness or redness as any film former can occasionally trap heat or sweat and provoke irritation.
The polymer is fully synthetic with no animal derived building blocks so it is considered appropriate for vegans and vegetarians.
The large molecular size keeps absorption through intact skin negligible which means it is generally viewed as low risk for women who are pregnant or breastfeeding. This is not medical advice and anyone expecting or nursing should clear new products with a doctor first.
Polyurethane-11 is not known to trigger photosensitivity and it plays well with common actives like vitamin C or retinoids since it sits on the surface rather than interacting chemically.
Potential Side Effects/Adverse Reactions
Responses to topical Polyurethane-11 differ from person to person. The points below list potential side effects that could occur yet they are unlikely for most users when the ingredient is formulated and used correctly.
- Mild skin irritation such as redness itching or tightness
- Contact dermatitis in individuals allergic to residual isocyanates or solvents
- Temporary clogged pores if heavy layers build up without proper cleansing
- Eye stinging or watering if mascara or liner runs into the eye before fully setting
- Scalp or hair dullness when used in styling sprays and not washed out regularly
If any of these reactions occur stop using the product and seek guidance from a healthcare professional or dermatologist.
Comedogenic Rating
Rating: 1/5. Polyurethane-11 is a large molecular weight polymer that sits on the surface rather than sinking into pores, so it is classed as very low on the comedogenic scale. A rating of 1 accounts for the fact that any film former can create a physical barrier that traps sweat or sebum if layered heavily and not cleansed off, which could contribute to the occasional blocked pore. Overall it is considered suitable for acne-prone or breakout-prone skin. Regular, thorough cleansing at the end of the day helps keep the risk minimal.
Summary
Polyurethane-11 is used primarily as a film former, creating a thin flexible layer that locks makeup pigments in place, boosts water and transfer resistance and helps active ingredients stay where they are applied. Its popularity is steady in long wear foundations, mascaras and sunscreens though it is not as widely recognised by consumers as silicone or acrylic counterparts. Safety reviews find it low risk because it remains on the surface and is rarely sensitising. Still, skin can be unpredictable so patch testing any new product containing Polyurethane-11 is a smart step before full-face use.