Decalin (decahydronaphthalene, also known as bicyclo[4.4.0]decane), a bicyclic organic compound, is an industrial solvent. A colorless liquid with an aromatic odor, it is used as a solvent for many resins or fuel additives. It is the saturated analog of naphthalene and can be prepared from it by hydrogenation in a fused state in the presence of a catalyst. Decahydronaphthalene easily forms explosive organic peroxides upon storage in the presence of air.