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

The physical properties of ethanol are primarily related to the properties of its low-carbon straight-chain alcohols. The hydroxyl group in the molecule can form hydrogen bonds, resulting in a high viscosity for ethanol and less polarity compared to organic compounds with a similar relative molecular mass. At room temperature, ethanol is colorless and has a distinctive, aromatic vapor.