E500: Sodium carbonate

What is E500?

Sodium carbonate (E500i), also known as soda ash or washing soda, is an alkaline sodium salt of carbonic acid. It is a white, water-soluble powder that raises the pH of foods and releases carbon dioxide when it reacts with acids.

Origin and production

It is produced industrially from salt and limestone using the Solvay process, or refined from naturally occurring mineral deposits such as trona. Historically it was obtained from the ashes of certain plants.

Why is it used?

It acts as an acidity regulator and raising agent. It is a traditional component of 'kansui', the alkaline water that gives ramen and instant noodles their springy texture and yellowish colour, and it aids leavening and browning in some biscuits.

Vegan, vegetarian and halal

Sodium carbonate is a mineral-derived compound with no animal input, so it is generally suitable for vegans and vegetarians and is not a concern for halal or kosher diets in itself.

Safety and regulation

E500 is authorised as a food additive in the EU and has been evaluated by EFSA. It is permitted in a wide range of foods, generally at levels limited by good manufacturing practice.

Common in