辛酸是八个碳的直链羧酸。常温下为无色油状液体。辛酸微溶于水，溶于多数有机溶剂。

用于制染料、药物、防腐剂、杀菌剂等。

Caprylic acid is the common name for the eight-carbon saturated fatty acid known by the systematic name octanoic acid. Its compounds are found naturally in the milk of various mammals, and as a minor constituent of coconut oil and palm kernel oil. It is an oily liquid that is minimally soluble in water with a slightly unpleasant rancid-like smell and taste.