Sodium phosphate (mono-; di-; and tribasic)

Additive · E 339(i)

Sodium phosphates are three sodium salts of phosphoric acid used to control acidity, hold moisture and keep food mixtures stable. They appear in foods such as processed cheese and prepared meats. E339 identifies these orthophosphates, which differ from sodium pyrophosphates and polyphosphates.

Also known as

sodium phosphates · monosodium phosphate · sodium dihydrogen phosphate · sodium phosphate monobasic · monobasic sodium phosphate · sodium acid phosphate · sodium biphosphate · disodium phosphate · disodium hydrogen phosphate · sodium phosphate dibasic · dibasic sodium phosphate · trisodium phosphate · trisodium orthophosphate · sodium phosphate tribasic · tribasic sodium phosphate · E 339(i) · E339(i) · INS 339(i) · E 339(ii) · E339(ii) · INS 339(ii) · E 339(iii) · E339(iii) · INS 339(iii)

Why PRūF tracks it

Cumulative phosphorus exposure, reduced kidney clearance and blood-pressure changes in small sodium-phosphate trials warrant attention, while current evidence does not establish cancer or long-term kidney, bone or cardiovascular disease from typical individual food uses.

Read the research

Sodium phosphates supply readily absorbed phosphorus and sodium. The main concern is total phosphorus exposure and the kidneys’ ability to remove it. EFSA set a full-diet intake value of 40 milligrams of phosphorus per kilogram of body weight daily; some child and adolescent exposure estimates exceeded it, and it does not cover moderate-to-severe kidney impairment. JECFA’s 2026 review retained its differently derived group value of 70 milligrams.

These values concern phosphorus, not the weight of sodium-phosphate salt. Direct human evidence includes a twenty-person trial in which about six weeks of added sodium phosphate raised blood pressure despite a sodium-matched comparison. A smaller fixed-order study also found higher systolic pressure. Both used substantial supplemental phosphorus and had design limitations.

Another trial found short-term mineral changes after a monosodium-phosphate challenge without corrected glucose or lipid effects. Trials of mixed phosphate additives show hormone changes, including in kidney disease, but have not established fractures, cardiovascular events or progressive kidney damage. A French cohort’s sodium-phosphate coronary association failed correction for multiple testing. A small trisodium-phosphate mouse study reported intestinal changes but did not measure functional permeability or establish human allergy.

The review considers cumulative exposure, kidney vulnerability and direct physiological signals, while long-term harm from typical individual food uses remains uncertain.

Research reviewed on September 5, 2026 · 12 sources