Butyraldehyde appears as a clear liquid with a pungent odor. Flash point 20°F. Boiling point 75.7°F (Hawley's). Less dense than water and insoluble in water. Vapors heavier than air.Butanal is a member of the class of butanals that consists of propane bearing a formyl substituent at the 1-position. The parent of the class of butanals. It has a role as a biomarker, an Escherichia coli metabolite and a mouse metabolite