Potassium Sorbate

Potassium sorbate is the potassium salt of sorbic acid, which is used in cosmetics to extend the shelf-life of a product by inhibiting the development of mold and yeast. It is not very potent, with action weak against bacteria, but functions well against fungi. For potassium sorbate to be active, it must be converted into the form of sorbic acid, and this takes place in the presence of water when pH is acidic, between 3 and 4. Even under these perfect conditions, it is not strong enough to be used on its own and is combined with other preservatives to make its effectiveness even better. Potassium sorbate is also used as a food preservative and carries the label E202.