Benzoic acid is produced by the oxidation of toluene. The salts of benzoic acid are made by reacting the acid with the appropriate hydroxide. Sodium benzoate is by far the most common of the three salts used in commerce. Sodium benzoate are used as preservatives against yeasts and moulds. They have less effect against bacteria. They have been used since the early 1900s. They are often synergistic with other preservatives, such as sorbates, and are used in conjunction with sulphur dioxide, which itself inhibits enzyme action and browning.

Calcium propionates are white, free-flowing, water-soluble salts, manufactured by the reaction of propionic acid with carbonates or hydroxides. They are readily digested and metabolised in the body. Calcium propionates are used to extend the mould-free shelf-life of bakery products, cheese and cheese products. They blend well with other ingredients and do not alter the colour, taste or texture at normal usage levels, It can extend the shelf life of food and feed products by interfering with the growth of microorganisms such as mould and bacteria. It is also used in agriculture as a food supplement and to prevent milk fever in a cow.