What Is Polyurethane-71?
Polyurethane-71 is a man-made polymer created to give cosmetic products flexible hold and smooth feel. It starts with a base called a polyester diol, which is produced by combining hexanediol, adipic acid and isophthalic acid. This base is then linked with isophorone diisocyanate and a small helper molecule named dimethylolpropionic acid. After that, triethylamine is added to balance the mix, and the whole blend is dispersed in water with the help of isopropanolamine and ethylene diamine. The result is a water-friendly polymer that can form clear thin films on skin or hair.
Polyurethane-71 entered the beauty world in the late 1990s when chemists searched for lighter, more flexible film formers than traditional hairspray resins. Its ability to stay clear and move with the skin quickly made it popular in modern formulas. You can now spot it in sheet masks, peel-off masks, long-wear makeup, brow gels, liquid eyeliners, transfer-resistant foundations, hair styling creams and anti-aging serums that need a smooth film to hold active ingredients close to the skin.
Polyurethane-71’s Cosmetic Benefits/Uses
When added to a formula Polyurethane-71 delivers two main technical perks that translate into user-friendly benefits.
- Binding: Helps different ingredients stick together so pigments, powders and actives stay evenly mixed. This keeps color true, prevents separation and improves shelf life.
- Film Forming: Creates a thin flexible layer on skin or hair that locks in moisture, boosts wear time of makeup, gives a soft focus finish and offers light hold in styling products.
Who Can Use Polyurethane-71
Polyurethane-71 is generally well tolerated by all skin types. Its lightweight flexible film does not clog pores so oily and acne-prone skin usually handles it without trouble while dry and mature skin appreciate the moisture-locking layer it creates. Sensitive skin tends to do fine as the polymer has a low irritation profile but anyone with a known allergy to polyurethanes should proceed with caution.
The ingredient is made entirely from synthetic petrochemical sources and contains no animal-derived compounds so it is suitable for both vegans and vegetarians. That suitability can only be guaranteed if the finished product has also avoided animal testing and animal additives in other parts of the formula.
Because Polyurethane-71 is a large molecule that sits on top of skin rather than being absorbed it is not expected to pose a risk during pregnancy or breastfeeding. Still this is not medical advice and pregnant or nursing users should show any product to their doctor before adding it to a routine.
The polymer is not known to cause photosensitivity so it will not make skin more prone to sunburn. Standard daytime sun protection is still wise whenever you use cosmetics.
Potential Side Effects/Adverse Reactions
Reactions to topical Polyurethane-71 differ from person to person. The points below list potential side effects that could occur even though they are not the norm for most users when the ingredient is used correctly in a finished product.
- Contact irritation: Mild redness stinging or itching can happen on very reactive skin especially if the product contains other sensitizing ingredients
- Allergic contact dermatitis: Rare but possible in people already allergic to polyurethane resins or isocyanate residues
- Eye discomfort: If the polymer gets into the eyes it may cause watering or a gritty feeling until rinsed out
- Product buildup on hair: Repeated use in styling products can leave a thin film that feels heavy or appears dull until washed away
- Aerosol inhalation concerns: Using spray products in poorly ventilated areas may trigger coughing or throat irritation in sensitive individuals
If you experience any of the above reactions stop using the product and consult a healthcare professional
Comedogenic Rating
Rating: 0 (non-comedogenic)
Polyurethane-71 is a large water-dispersible polymer that forms a breathable film on top of skin instead of sinking into pores. It carries no oily or waxy fractions that could block follicles so it is considered non-comedogenic.
Because of this low clogging risk it is generally fine for people who are prone to acne or breakouts. If a finished product with Polyurethane-71 still causes congestion the culprit is more likely another ingredient such as rich oils or butters.
Summary
Polyurethane-71 gives formulas two clear benefits: it binds ingredients together so pigments and actives stay even and it forms a thin flexible film that locks in moisture boosts wear time of makeup and offers light hold in hair products. It achieves these results thanks to its carefully balanced polymer backbone that stays clear flexible and water friendly.
The ingredient enjoys steady popularity in long-wear makeup brow gels sheet masks and styling creams though it is not as talked about as buzzier actives. Formulators appreciate its reliability which keeps it in many modern formulas.
Overall safety is high with a low record of irritation or allergies. Still every skin is different so it is wise to patch test any new product that features Polyurethane-71 before full use.