What Is Polyurethane-32?
Polyurethane-32 is a synthetic copolymer created from 1,4-butanediol, ethylenediamine, hexamethylene diisocyanate, isophorone diisocyanate and sodium N-(2-aminoethyl)-3-aminoethane sulfonate. These building blocks join together in a step-growth reaction to form long chains that carry sulfonate groups, allowing the material to disperse in water and blend smoothly into cosmetic formulas.
Polyurethane chemistry has been used since the 1950s for coatings and flexible foams. In the late 1990s formulators began adapting water-dispersible polyurethanes for personal care because they create flexible films without the tacky feel of older resins. Polyurethane-32 is one of these newer grades. It is produced by carefully controlling the ratio of the diisocyanates with diols and diamines, then neutralising the sulfonate groups to yield a stable, self-emulsifying dispersion suitable for cosmetic use.
You will commonly spot Polyurethane-32 in long-wear makeup such as liquid foundations, eyeliners and mascaras, in transfer-resistant lip colours, as well as in hair gels, skin primers, sheet masks and certain water-based moisturisers where a light film is desirable.
Polyurethane-32’s Cosmetic Benefits/Uses
In formulations Polyurethane-32 serves one primary purpose that can make a noticeable difference in product performance.
Binding: The polymer forms an invisible flexible network that binds pigments, powders and other actives to each other and to the skin or hair. This improves product cohesion, reduces cracking or flaking and extends wear time while maintaining a comfortable feel.
Who Can Use Polyurethane-32
Because Polyurethane-32 forms a lightweight, breathable film it is generally suitable for normal, dry, combination and oily skin. Its low occlusion means it will not trap large amounts of sebum so even acne-prone users usually tolerate it well. Those with very sensitive or highly reactive skin should still monitor how they feel, as any synthetic polymer can cause irritation for a small minority.
Polyurethane-32 is fully synthetic and contains no animal-derived raw materials so it is considered appropriate for both vegetarians and vegans. Cruelty-free status will depend on the finished brand’s animal testing policies rather than the polymer itself.
The molecule is too large to penetrate deeply and is not known to interfere with hormonal pathways, so it is generally viewed as safe for people who are pregnant or breastfeeding. This is not medical advice; anyone expecting or nursing should confirm product choices with a qualified physician.
Polyurethane-32 does not absorb UV light in a way that would trigger photosensitivity, nor does it degrade into photoreactive by-products, so daytime use poses no additional sun-related concerns.
Potential Side Effects/Adverse Reactions
Individual responses to topical Polyurethane-32 vary. The effects listed below are possible but uncommon when the ingredient is formulated and used correctly.
- Mild skin irritation such as itching or stinging, typically in very sensitive complexions
- Allergic contact dermatitis presenting as redness, swelling or small bumps
- Transient eye irritation if the product accidentally gets into the eyes
- Rare pore congestion or folliculitis when very heavy layers are applied to excessively oily skin
If any unwanted reaction occurs stop using the product and consult a healthcare professional or dermatologist.
Comedogenic Rating
Comedogenic rating: 1/5
Polyurethane-32 forms a thin breathable film that lets excess oil escape instead of trapping it in the pore. Its large molecules stay on the surface and are used at low levels, keeping clogging risk very low. Problems are unlikely unless the ingredient is layered heavily with already greasy products.
With this low score most acne-prone users can include Polyurethane-32 in their routine without added concern.
If you wear long-wear makeup daily a thorough evening cleanse helps prevent any residue from lingering in pores.
Summary
Polyurethane-32 is a water dispersible film former that binds pigments powders and active ingredients into a flexible mesh on skin or hair. This boosts colour payoff, curbs flaking and keeps products in place through heat sweat and daily movement while still feeling light.
You will see it in long wear makeup, hair gels and some modern moisturisers. It is not as well known as silicones but its soft long lasting finish is making it steadily more popular with formulators.
Research shows it is non toxic, rarely irritating and low on the clogging scale, so most people can use it with confidence. As with any new skincare ingredient do a quick patch test when trying a product that features Polyurethane-32 to be on the safe side.