It is a colourless oily liquid with a rancid smell that produces irritating vapour. Propionic acid is a short-chain saturated fatty acid that consists of ethane attached to the carbon of a carboxy group
Propionic acid is used in the manufacture of herbicides, fine chemical intermediates, rubber chemicals, emulsions, and environmentally friendly solvents for coating formulations, artificial fruit flavors, pharmaceuticals, and modified synthetic cellulose fibers (e.g., cellulose acetate propionate).