Propionic acid is a clear, colorless liquid with a slightly sweetish odor. It is soluble in water and alcohol; melts at -21 C, boils at 141 C. It is used as a preservative in feed and food industry directly or in the forms of ammonium propionate, calcium and sodium propionates. It is used to manufacture various propionates which used in the production of pharmaceuticals, antifungal agents, agrochemicals, plastics, plasticizers, rubber chemicals, dyes, artificial flavors and perfumery synthetics. It is used also as a solvent and in nickel-electroplating solutions. Propionates (Calcium, Potassium, Sodium) are approved to use as preservatives in food and feed. They have effective antimicrobial activity. They also contribute to diet supplements.