What Is Polyurethane-95?
Polyurethane-95 is a synthetic film-forming polymer created by combining two forms of poly(1,4-butanediol), Hydrogenated Bisphenol A, and Isophorone Diisocyanate, then sealing the chain with 2-Hydroxyethyl Acrylate. The result is a clear flexible resin that behaves like a liquid plastic when dispersed in cosmetic formulas. Work on urethane polymers for cosmetics began in the late 1980s as chemists searched for lightweight substitutes for older resins that could feel heavy or chip easily. Polyurethane-95 gained traction in the 2000s when nail polish brands needed stronger, smoother coats without the strong odor linked to nitrocellulose systems.
Manufacturing starts with controlled reactions between the diols and diisocyanate to build long urethane chains. Hydrogenated Bisphenol A adds strength and shine while the final cap of 2-Hydroxyethyl Acrylate keeps the polymer from cross-linking too much, so it stays usable in liquid form. After the reaction, the resin is purified, ground into a fine powder, or dissolved in a safe solvent ready for blending.
You will mainly spot Polyurethane-95 in nail polishes, base and top coats, long-wear eye shadows, liquid eyeliners, and certain mascara films. It also appears in peel-off face masks and transfer-resistant lip colors where a thin durable film is key.
Polyurethane-95’s Cosmetic Benefits/Uses
This ingredient pulls double duty in beauty products
- Binding – Acts like glue inside a formula helping pigments, glitter, or active ingredients stick together and stay evenly spread on the skin or nail. This gives smoother application, prevents settling and boosts wear time
- Nail conditioning – Forms a flexible yet tough layer that protects the nail plate from chipping and water loss. Regular use can leave nails feeling harder and looking glossier
Who Can Use Polyurethane-95
Polyurethane-95 suits most skin types including normal, dry, oily and combination because it is largely inert on the skin’s surface and does not clog pores for the majority of users. Highly sensitive or eczema-prone skin should proceed with care since any polymer film can trap heat or sweat and aggravate flare-ups if worn for long periods.
The polymer is fully synthetic with no animal-derived inputs so products made with it are generally considered suitable for vegans and vegetarians, provided the rest of the formula follows the same standard.
Current data shows no meaningful skin penetration and no link to hormonal activity, so Polyurethane-95 is not expected to pose a risk for pregnant or breastfeeding women. This is not medical advice and anyone who is expecting or nursing should ask a doctor before starting a new cosmetic just to be safe.
The ingredient does not cause photosensitivity and has no known interactions with sunlight or UV treatments, making it a good choice for day and night wear.
Potential Side Effects/Adverse Reactions
Side effects from topical use of Polyurethane-95 vary from person to person. The points below are possible reactions yet they are uncommon when the ingredient is used correctly in a finished product.
- Mild skin irritation – A small number of users may notice redness, itching or a tight feeling where the film sits
- Allergic contact dermatitis – People with an existing acrylate or urethane allergy could develop a rash or swelling
- Eye stinging – If mascara or liquid liner containing Polyurethane-95 flakes into the eye it can cause temporary discomfort
- Nail brittleness – Wearing very hard long-wear nail varnish for extended periods may lead to drier or more brittle nails once the polish is removed
If any of these reactions occur stop use at once and consult a healthcare professional or pharmacist for guidance.
Comedogenic Rating
Rating: 1 out of 5
Polyurethane-95 is a large, water-insoluble polymer that stays on the surface instead of sinking into pores, so it is unlikely to mix with skin oils or block follicles. Because it creates a thin breathable film rather than a heavy waxy layer it earns a very low comedogenic score. Most acne-prone users should find it compatible with their routines, though the overall formula still matters.
Keep in mind that long-wear makeup built around any film former can require stronger cleansers for removal. Inadequate cleansing can leave residue that indirectly contributes to breakouts, so thorough removal at the end of the day is advised.
Summary
Polyurethane-95 works mainly as a binder and nail conditioner. Its flexible resin network glues pigments, shimmer or actives in place giving smoother glide and longer wear, while the same network forms a protective shell over nails that helps reduce chipping and water loss. These benefits come without adding weight or strong odors that older resins sometimes bring.
The ingredient sits in a niche spot, popular with long-wear nail polishes, liquid eyeliners and transfer-resistant shadows but still less common than classic film formers like nitrocellulose. As more brands push for lightweight high-performance textures its use has been slowly increasing.
Current safety data shows low irritation potential, negligible skin penetration and no photoreactivity, so it is considered safe for the vast majority of consumers. As with any new cosmetic, doing a small patch test when first trying a product containing Polyurethane-95 is a smart way to rule out individual sensitivities.