Octadecane is widely used in the production of phase change materials (PCMs) for thermal energy storage systems. Its ability to absorb and release large amounts of heat during phase transitions makes it ideal for applications in building insulation, solar energy storage, and temperature regulation in textiles. Additionally, it serves as a standard reference in gas chromatography for the calibration of instruments due to its well-defined retention time and stability. In the cosmetics industry, octadecane is utilized as an emollient and thickening agent in skincare products, providing a smooth texture and enhancing the spreadability of formulations. It is also employed in the synthesis of surfactants and lubricants, where its long hydrocarbon chain contributes to effective surface tension reduction and lubrication properties.