Decalin is a colorless liquid hydrocarbon that consists of two fused cyclohexane rings. It is commonly used as a solvent in chemical reactions and as a starting material in the synthesis of various organic compounds. Decalin can exist in two isomeric forms: cis and trans, which differ in the arrangement of their hydrogen atoms. This compound is primarily utilized in the petrochemical industry and in laboratories for research purposes. Due to its relatively low toxicity, Decalin is favored in applications where safer solvents are required. It has a distinctive odor and is flammable, necessitating careful handling.