Propionic acid

Propionic acid (/proʊpiˈɒnɪk/, from the Greek words protos, meaning "first", and pion, meaning "fat"; also known as propanoic acid) is a naturally occurring carboxylic acid with chemical formula CH₃CH₂CO₂H. It is a liquid with a pungent and unpleasant smell somewhat resembling body odor. The anion CH₃CH₂CO₂⁻ as well as the salts and esters of propionic acid are known as propionates or propanoates.