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, with a unique, pleasant fragrance and a slight irritant quality. 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, 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 odor as a volatile liquid.