Long não, whose IUPAC name is 1,7,7-trimethylbicyclo[2.2.1]heptan-2-one, is a terpenoid organic compound with a chemical formula of C10H16O. It is a white or transparent waxy solid at room temperature and can be used to repel insects. Long não is extracted from the trunk of long não tree. The older the long não tree, the more long não is in it. The extraction method is to cut the tree trunk into small pieces and distill it with water. After the long não oil is heated, it rises with water vapor, and it can form long não when it comes into contact with the pottery jar placed above to cool it. In the early days of northern Taiwan, the mountain forests were mostly primitive long não forests, and many old long nãocây đã hơn một nghìn năm tuổi. Sau đó, chính phủ Nhật Bản đã cắt giảm một lượng lớnlong não for export in Taiwan. Therefore, Taiwan's long não export once reached the first place in the world. Most of the mothballs used in the world are synthesized chemically.This substance may be harmful to the environment, and special attention should be paid to water bodies.Store in a sealed, ventilated, dry place, avoid contact with other oxides.