Sodium benzoate is a white crystalline or amorphous powder that's used as a preservative in many foods and soft drinks. It's also used as a corrosion inhibitor, fragrance, and pickling agent. Sodium benzoate is the sodium salt of benzoic acid and is also known as benzoate of soda. It's odorless, tasteless, and highly soluble in water. 

Sodium benzoate is used as a preservative because it has antibacterial, antifungal, and bacteriostatic properties that inhibit the growth of mold, yeast, and bacteria. It's especially effective in food products with a pH of less than 4.5 and is stable in mildly acidic conditions. The FDA considers sodium benzoate GRAS (generally regarded as safe) for use as a preservative in food. 

Sodium benzoate is a white crystalline or amorphous powder that has many uses, including as a preservative, corrosion inhibitor, and fragrance:

Preservative

Sodium benzoate is used in many foods to prevent the growth of yeast and molds, especially in acidic foods with a pH of less than 4.5. It's added to foods like mayonnaise, margarine, carbonated drinks, jams and jellies, sauces, tomato paste, salad dressings, pickles, condiments, and frozen yogurt toppings. It can help keep products shelf-stable for at least two years from the date of purchase. 

Corrosion inhibitor

Sodium benzoate is used to deter corrosion, such as in coolants for car engines. 

Fragrance

Sodium benzoate is used in cosmetics and personal care items, such as hair products, baby wipes, toothpaste, and mouthwash. 

Therapy

Sodium benzoate is used as a treatment for urea cycle disorders because it binds amino acids. It has also been studied as a treatment for maple syrup urine disease and panic disorder. 

Other uses

Sodium benzoate is used in fireworks as a fuel in whistle mix, and it may be used as a stabilizer in photo processing and to improve the strength of some types of plastic