Hexanoic acid, also known as caproic acid, is a six-carbon saturated fatty acid. It is a colorless liquid with a strong, unpleasant odor, often associated with rancid butter. Hexanoic acid is found naturally in some animal fats and oils, as well as in certain plants. It is commonly used in the production of esters for flavorings and fragrances. In addition to its use in the food and cosmetic industries, hexanoic acid plays a role in the manufacture of plasticizers and surfactants. It can also be used in the synthesis of various chemical compounds. Due to its strong odor, hexanoic acid is typically handled with care in industrial settings.