Disodium phosphate
A sodium salt of phosphoric acid used in foods to control acidity (pH), help fats and water stay mixed, bind minerals like calcium, and improve texture—especially in processed cheese.
Should I eat Disodium phosphate?
Disodium phosphate is a highly refined mineral salt that improves texture by controlling acidity and binding minerals, but it also adds extra phosphorus to your diet. If you rely on many processed foods or have reduced kidney function, choose products without “phos‑” additives (or with citrate instead) to keep intake in check.
Summary
Disodium phosphate (E339(ii)/INS 339(ii)) is made by neutralizing phosphoric acid with sodium salts. It acts as an acidity regulator and emulsifying salt in foods like processed cheese, dairy drinks, and some meats and baked goods. Safety reviews find low acute toxicity with no genotoxic or carcinogenic concern, and FDA lists sodium phosphates as GRAS. EFSA set a group acceptable daily intake of 40 mg phosphorus per kilogram of body weight per day from phosphate additives and noted that high consumers—especially children—can exceed this when several processed foods are combined. To cut back, scan ingredient lists for “phos‑” names and pick options that use fewer phosphate additives.
Key Research Points
Watch total phosphorus intake
In 2019, EFSA set a group ADI of 40 mg phosphorus per kilogram of body weight per day for phosphate additives and noted that high consumers, especially children, can exceed it. This limit applies to your whole diet, not a single food.
Approved, but use is bounded
FDA lists sodium phosphates as GRAS, and Codex/EU permit disodium phosphate (E339(ii)/INS 339(ii)) for defined functions. Safety reviews report no genotoxic or carcinogenic concern.
Kidney disease needs caution
EFSA states the ADI does not apply to people with moderate‑to‑severe kidney impairment, who can accumulate phosphate more readily. If your kidney function is reduced, limit foods with phosphate additives.
Overview
What is it?
Why is it used?
Origin
Phosphates entered modern food processing in the early 1900s with processed cheese. Swiss researchers in 1911 showed that adding phosphate/citrate salts to melted cheese created a smooth emulsion that could be cooled and sliced, extending shelf life and enabling consistent texture in ‘pasteurized process’ cheeses. Today, disodium phosphate (Na₂HPO₄) is made by neutralizing mineral-derived phosphoric acid with sodium bases and is widely used in dairy and other processed foods.
Process: Neutralization, crystallization, drying & milling
Steps
Chemicals
Research & Safety
Potential Concerns
For most healthy adults, typical food levels are considered safe, but total intake from multiple phosphate‑containing foods can add up. EFSA’s group ADI for phosphate additives is 40 mg phosphorus/kg/day; high consumers—especially children and teens—may exceed this. People with reduced kidney function are more vulnerable because they clear phosphorus less efficiently, and additive phosphate is highly absorbable. Very large medicinal doses (e.g., bowel preparations) can cause dangerous electrolyte shifts and kidney injury in at‑risk individuals; this does not reflect food uses.
Potential Benefits
No demonstrated nutrimental benefit.
Digestive Effects
At the small amounts used in foods, disodium phosphate is generally well tolerated. Excess intake from drug products (or misuse of laxatives containing sodium phosphate) can cause diarrhea, dehydration, and electrolyte imbalances. People with kidney disease, older adults, and those on certain medications (e.g., diuretics, ACE inhibitors, ARBs, NSAIDs) are more sensitive to these effects at medicinal doses. If you experience unusual swelling, low urine output, or severe weakness after taking sodium phosphate as a drug, seek medical care.
Limit Consumption
People with chronic kidney disease should limit foods with phosphate additives because inorganic phosphate is more completely absorbed and can increase phosphate burden despite normal blood tests early in CKD. Children and adolescents who eat many ultra‑processed foods may surpass EFSA’s ADI for additive phosphorus. Infants are regulated under specific formula rules, but EFSA noted potential ADI exceedance from the total diet and from supplements. Consumers using sodium phosphate–based bowel preps or laxatives should follow label directions strictly and consult clinicians if they have kidney, heart, or bowel conditions.