Furfural is an organic compound with the formula C₄H₃OCHO. It is a colorless liquid, although commercial samples are often brown. It has an aldehyde group attached to the 2-position of furan. It is a product of the dehydration of sugars, as occurs in a variety of agricultural byproducts, including corncobs, oat, wheat bran, and sawdust. The name furfural comes from the Latin word furfur, meaning bran, referring to its usual source. Furfural is only derived from lignocellulosic biomass, i.e., its origin is non-food or non-coal/oil based. In addition to ethanol, acetic acid, and sugar, furfural is one of the oldest organic chemicals available readily purified from natural precursors.