Fusel oil is a poisonous, clear, colorless liquid with a disagreeable smell. It consists of a mixture of amyl alcohol, obtained as a by-product of the fermentation of plant materials containing sugar and starch. Fusel oil also occurs as a dangerous impurity in badly made spirit drinks. It is used as a solvent for waxes, resins, fats, and oils, and in the manufacture of explosives and pure amyl alcohols.