2H-1-Benzopyran-2-one

Coumarin (2H-1-Benzopyran-2-one) is a bicyclic lactone compound with a characteristic sweet, hay-like, vanilla-tonka bean aroma, naturally found in tonka beans (Dipteryx odorata), sweet clover, and cassia bark. It is a regulated fragrance ingredient under IFRA and EU cosmetic regulations due to its known sensitization potential, requiring declaration on product labels when present above 0.001% in leave-on products and 0.01% in rinse-off products. Formulators use it as a key fixative and olfactory modifier in fine fragrances, aftershaves, and personal care products, where it imparts warm, powdery, and woody nuances, though its use is subject to strict concentration limits.