The structural formula of recycled waste ethanol is C2H5OH, commonly known as alcohol. It is a flammable and volatile colorless transparent liquid under normal temperature and pressure. Its aqueous solution has a unique, pleasant aroma 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 straight-chain primary alcohol. The hydroxyl group in the molecule can form hydrogen bonds, making ethanol highly viscous and less polar than organic compounds with a similar molecular weight. At room temperature, ethanol is colorless and has a distinctive, aromatic odor as a volatile liquid.