The structural formula of recycled waste ethanol is C2H5OH, commonly known as alcohol. It is a flammable, volatile, colorless, and transparent liquid at room temperature and pressure, with a distinctive and pleasant odor, slightly irritating to the skin. Ethanol is used to produce acetic acid, beverages, perfumes, dyes, fuels, and more. In medicine, 70% to 75% ethanol solutions are commonly used as disinfectants.

Ethanol's physical properties are primarily related to the characteristics of its low-carbon straight-chain alcohols. The hydroxyl group in its molecules can form hydrogen bonds, making ethanol highly viscous and less polar than organic compounds of similar relative molecular mass. At room temperature, ethanol is colorless and has a distinctive, aromatic vapor.