What Is Polyurethane-16?
Polyurethane-16 is a man-made polymer created by joining two parts hexamethylene diisocyanate with one part polycaprolactonetriol. When these building blocks react they form a flexible three-dimensional net that is both tough and smooth, qualities that make it useful in beauty formulas. Polyurethanes as a group were first developed in the 1930s for coatings and foams and chemists later adapted certain grades for cosmetics once they noticed the materials could sit on skin without feeling heavy. Polyurethane-16 entered makeup labs in the late 1990s after suppliers learned how to make cosmetic-grade batches with low levels of irritating leftovers from the reaction.
The manufacturing process involves carefully mixing the two raw ingredients at controlled temperatures so they link together just enough to form a stable network but remain fluid enough to pour. After curing, the polymer is ground into a fine powder or dispersed in water or a light solvent, ready to be blended into cosmetic bases.
You will most often spot Polyurethane-16 in pressed powders, loose powders, long-wear foundations, mascaras, eyeliners, setting sprays, hair styling products, sunscreens and some peel-off face masks. Brands like it because it adds grip and durability without a noticeable film or sticky feel.
Polyurethane-16’s Cosmetic Benefits/Uses
Formulators choose Polyurethane-16 for two main reasons that directly improve how a product looks and feels on skin or hair.
- Anticaking: The polymer coats individual powder particles so they glide over each other instead of clumping. This keeps pressed and loose powders smooth in the compact, easier to pick up with a brush and more even when applied, preventing patchy spots on skin.
- Film Forming: Once the product dries Polyurethane-16 creates a thin flexible layer that helps pigments and active ingredients stay in place longer. In makeup this means better wear time, less smudging and improved resistance to water or sweat. In hair products the film adds light hold and shine without stiffness.
Who Can Use Polyurethane-16
Polyurethane-16 is generally friendly to all skin types including oily, combination, normal and dry because it sits on the surface without clogging pores or drawing out moisture. People with extremely sensitive or eczema-prone skin should watch for any irritation as trace leftovers from the manufacturing reaction could trigger redness in rare cases.
The polymer is fully synthetic with no animal-derived raw materials so it is suitable for vegans and vegetarians. As always cruelty status depends on the finished brand’s testing policies.
There is no evidence that Polyurethane-16 penetrates deeply or enters the bloodstream so it is not expected to pose a risk for pregnant or breastfeeding women. This is not medical advice and anyone who is pregnant or nursing should show the full ingredient list of any product to their healthcare provider for personal guidance.
The ingredient does not make skin more sensitive to sunlight and it does not interfere with SPF filters, so no extra sun precautions are needed beyond normal daily protection.
Potential Side Effects/Adverse Reactions
Side effects from topical use of Polyurethane-16 vary between individuals. The issues listed below are possible yet unlikely when the ingredient is used at the levels allowed in cosmetics.
- Mild skin redness or itching, especially on very sensitive skin
- Contact dermatitis in people allergic to residual isocyanates
- Watery eyes or stinging if loose powder gets into the eye area
- Temporary coughing or throat irritation if a cloud of product is inhaled during application
- Build-up on hair shafts that can leave strands feeling coated after repeated use without thorough cleansing
If any persistent irritation or discomfort occurs stop using the product and consult a healthcare professional.
Comedogenic Rating
Rating: 1 out of 5 – low likelihood of clogging pores
Polyurethane-16 is a large, water-insoluble polymer that stays on the surface instead of soaking into the pore lining, and it is not oily or waxy like many higher-risk ingredients. These qualities make it unlikely to trap sebum or dead cells, so breakouts are rare. In most cases this ingredient is safe for people who are prone to acne, though individual responses can vary.
Because the polymer forms a breathable, flexible film, it can actually help keep excess oil in place under makeup rather than spreading across the face. Still, very heavy layers combined with poor cleansing could allow residues to build up over time, so thorough nightly removal is wise.
Summary
Polyurethane-16 is used in cosmetics mainly for two jobs: it stops powders from caking and it creates an invisible, flexible film that locks makeup or styling products in place. By coating particles and forming a light mesh on skin or hair, it delivers smoother texture, longer wear and better resistance to sweat and water.
This polymer is popular with formulators who want long-wear performance without a sticky feel, yet it is not as widely talked about as silicone or acrylic alternatives because it usually sits quietly on an ingredient list doing its job. Safety studies and real-world use show a low rate of irritation or pore blockage, and the ingredient does not penetrate skin to any meaningful depth.
Overall, Polyurethane-16 is considered safe for regular cosmetic use. As with any new product, it is smart to patch test first to catch any personal sensitivities before applying it over larger areas.