Is polyurethane a safe material?

Polyurethane is considered a safe material in its fully cured solid form for most everyday uses, though it poses risks during application and manufacturing. Once cured, polyurethane becomes an inert plastic that does not release significant chemicals under normal conditions, which is why it is widely used on hardwood floors, furniture, children's toys, mattress foams, and even medical devices. It is approved for indirect food contact after full cure under FDA regulations and CertiPUR-US certified foams are tested for low emissions. However, during application, liquid polyurethane contains isocyanates and volatile organic compounds that are toxic if inhaled without a respirator, causing eye, nose, throat irritation, headaches, dizziness, and can trigger asthma and allergic reactions in workers. Sanding polyurethane creates fine dust that irritates lungs. New polyurethane foam can off-gas for a few days, causing temporary odor and mild irritation for sensitive individuals. Environmentally, polyurethane is not biodegradable and can become microplastics over time. So for consumers living with fully cured polyurethane floors or furniture, it is safe. For applicators and factory workers, it requires protective gear and ventilation to be safe. Overall, it is safe after curing, but not safe during wet application.