Propylene is an important industrial chemical used as a feedstock in the production of polypropylene, acrylonitrile, propylene oxide, 2‐propanol, alkylated fuels, and other chemicals. It is obtained from steam cracking in pyrolysis furnaces in olefins plants and in refinery catalytic‐cracking reactors. Distillation in multitray columns yields purities in excess of 99.5 wt%. The physical and chemical properties of propylene are well characterized. Under ambient conditions, it is a colorless gas and has anesthetic properties at high concentrations. Propylene is usually transported in the liquid state at high pressures. Proper precautions must be taken when handling propylene.