E340: Monopotassium phosphate

What is E340?

E340i is monopotassium phosphate, also called potassium dihydrogen phosphate, an acidic potassium salt of phosphoric acid. It is a white, water-soluble crystalline powder.

Origin and production

It is produced by partially neutralising purified phosphoric acid, obtained from phosphate rock, with potassium hydroxide or potassium carbonate. It is entirely mineral in origin.

Why is it used?

Monopotassium phosphate acts as a buffer and acidity regulator and supplies potassium and phosphorus. It is frequently used in sports and soft drinks, flavoured waters and powdered drink mixes, where it helps balance acidity and adds electrolytes.

Vegan, vegetarian and halal

E340i is a mineral salt suitable for vegans and vegetarians. It raises no particular halal or kosher concerns.

Safety and regulation

Monopotassium phosphate is authorised as a food additive in the European Union and was included in EFSA's 2019 re-evaluation of phosphates, which set a group acceptable daily intake for phosphorus from phosphate additives. It is also permitted in many other countries.

Common in