Oleic acid is a monounsaturated omega-9 fatty acid that occurs naturally in various animal and vegetable fats and oils. It is an odorless, colourless oil, although commercial samples may be yellowish. It has the formula CH3−(CH2)7−CH=CH−(CH2)7−COOH. The salts and esters of oleic acid are called oleates. It is part of many oils used in a lot of artificial food, as well as for soap.