NaC3H5O2

Sodium propionate, with the chemical formula NaC3H5O2, is the sodium salt of propionic acid (C3H6O2). It appears as a white crystalline solid that is highly soluble in water and is used in various industrial and consumer applications.

Production and structure

Sodium propionate is produced commercially by neutralizing propionic acid with sodium hydroxide. It can also arise as a component in some fermentation processes that generate propionic acid and its salts. In solution, it provides the propionate ion, and the corresponding acid–base equilibrium reflects the pKa of propionic acid (about 4.87).

Applications

The primary use of sodium propionate is as a food preservative. It inhibits mold and some bacteria, and is commonly added to bread, baked goods, cheeses, dairy products, and processed meats to extend shelf life. It is also employed as an acidity regulator and antimicrobial agent in a range of foods and cosmetic/pharmaceutical formulations.

Safety and regulatory status

Sodium propionate is generally recognized as safe (GRAS) for use as a food additive at approved levels. At typical exposure levels, it is of low toxicity, but handling in industrial settings should avoid inhalation of dust and contact with eyes or skin. As with other salts, excessive ingestion may cause gastrointestinal discomfort.

Properties and handling

In solid form, it is a stable, white crystalline compound. It should be stored in a cool, dry place in a tightly closed container to prevent moisture uptake. It is soluble in water, forming a basic aqueous solution due to the propionate anion.

See also

Propionic acid, Propionate, Sodium acetate.