E452: Sodium tripolyphosphate

What is E452?

Sodium tripolyphosphate (E452vi), often abbreviated STPP, is a phosphate salt consisting of three linked phosphate units with sodium. It is a white, water-soluble powder that binds to proteins and metal ions.

Origin and production

It is manufactured by heating a carefully controlled mixture of sodium phosphates, which are made from phosphoric acid derived from mined phosphate rock.

Why is it used?

STPP is used above all in seafood, such as frozen prawns, scallops and fish fillets, where it helps the flesh retain moisture during freezing, thawing and cooking. Because it also increases water uptake, its use in seafood is regulated and sometimes debated by consumer groups.

Vegan, vegetarian and halal

Sodium tripolyphosphate is mineral in origin and suitable for vegans and vegetarians as a substance, although it is mostly used in fish and meat products.

Safety and regulation

Polyphosphates are authorised in the EU with maximum levels and were re-evaluated by EFSA as part of the phosphate additive group, which set a group acceptable intake for phosphorus.

Common in