The structural formula of recycled waste ethanol is C2H5OH, commonly known as alcohol. It is a flammable and volatile, colorless, and transparent liquid at room temperature and pressure. Its aqueous solution has a distinctive, pleasant aroma with a slight刺激性. Ethanol is used to produce acetic acid, beverages, perfumes, dyes, fuels, and more. In medicine, 70% to 75% ethanol by volume is commonly used as a disinfectant.

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