Benzoic acid is the simplest aromatic carboxylic acid. It is a solid of colorless crystalline. Benzoic acid salts are used as a food preservative. Benzoic acid was discovered in the 16th century, and first described by Nostradamus, as he explained the dry distillation of gum benzoin. Benzoic acid is commercially produced through partial oxidation of toluene with oxygen, and is considered eco-friendly.