Acetic acid is one of the simplestcarboxylic acids, a clear colorless liquid that has a pungent odor. Acetic acid is a normal body metabolite in mammals and occurs naturally in a variety of foods. It is often used as an acidulant and preservative in food. Worldwide, the commonest use of acetic acid has been asvinegar. Typical vinegar (dilute acetic acid), which is used directly as a condiment, in the pickling of vegetables, and in other foods, contains acetic acid in the range of 5-20%. It is often used as an herbicide, microbiocide,fungicide, or pH-adjusting agent in certain manufacturing settings. It is irritating to skin andmucous membranesand, therefore, upon inhalation of its fumes can cause breathing difficulty.