Sodium Polyphosphate

About

What it is and where it shows up.

Sodium polyphosphate (E452i) is an inorganic sodium salt of polyphosphoric acid — most commonly found in its commercial form sodium hexametaphosphate (Graham's salt) — used in food as an emulsifier, stabiliser, sequestrant, and thickening agent. It is widely added to processed meats, dairy products, seafood, bakery items, and soft drinks to improve texture, water retention, and shelf-life.

Safety summary

The regulatory and scientific consensus.

EFSA (2019) established a group ADI of 40 mg phosphorus/kg body weight per day for all phosphate food additives (E338–E452); phosphates are considered of low acute oral toxicity with no genotoxicity or carcinogenicity concerns. However, the ADI explicitly does not apply to individuals with moderate to severe kidney dysfunction, and estimated dietary exposure may exceed the ADI for infants, toddlers, children, and adolescents even under average consumption scenarios. Rising processed-food phosphate intake has been linked in published literature to hyperphosphatemia and associated cardiovascular and renal risk.

Regulatory landscape

What food-safety regulators have decided.

Jurisdiction	Status	Note
FSANZ (Food Standards Australia New Zealand) (Australia)	Approved	Polyphosphates including INS 452(i) are permitted food additives under FSANZ Food Standards Code Standard 1.3.1 in specified food categories at regulated maximum use levels. No separate national ADI; JECFA/EFSA evaluations referenced.source
EFSA (European Food Safety Authority) (European Union)	Approved	Authorised under Regulation (EC) No 1333/2008 (Annex II and III) as amended by Commission Regulation (EU) No 1129/2011. Group ADI of 40 mg P/kg bw/day (expressed as phosphorus) covers the entire E338–E452 phosphate group. ADI does not apply to people with moderate to severe kidney dysfunction. Maximum permitted levels in food range from 500 to 20,000 mg/kg depending on food type. Ongoing re-evaluation call for additional technical data issued by European Commission in 2023.source
FDA (Food and Drug Administration) (United States)	Approved	Sodium hexametaphosphate (the predominant commercial form of E452i) is listed as GRAS under 21 CFR 182.6757. Permitted across multiple food applications under 21 CFR Part 182. No specific standalone ADI established by FDA; safe use governed by GMP conditions.source

Who should approach with care

Whose guidance would steer them away.

Kidney Disease — EFSA (2019) explicitly stated the group ADI for phosphates does not apply to individuals with moderate to severe reduction in renal function, as high phosphate intake is a recognised driver of hyperphosphatemia and associated cardiovascular mortality in CKD patients.

Children — EFSA estimated that dietary phosphate exposure may exceed the group ADI of 40 mg P/kg bw/day for infants, toddlers, and children under average consumption scenarios, and for adolescents with high-phosphate diets.

Infants — While EFSA found no immediate safety concern for infants below 16 weeks consuming formula, cumulative phosphate exposure from all food sources (including E452i-containing processed foods) may exceed the group ADI in older infants and toddlers.

Heart Disease — Published reviews link chronically elevated inorganic phosphate intake from food additives to hyperphosphatemia, endothelial dysfunction, and increased cardiovascular morbidity, warranting reduced exposure for individuals with pre-existing cardiac conditions.

Research citations

The sources behind this verdict.

1WHO. JECFA Food Additives and Contaminants Database – Sodium Polyphosphate (chemID 4669). apps.who.int
2FAO. GSFA Online Food Additive Details – Sodium Polyphosphate 452(i). fao.org
3PubMed. Hexametaphosphate, a Common Food Additive, Aggregated the Hen Egg White Lysozyme, 2023. pmc.ncbi.nlm.nih.gov
4EFSA. Re-evaluation of phosphoric acid–phosphates – di-, tri- and polyphosphates (E 338–341, E 343, E 450–452) as food additives and the safety of proposed extension of use, 2019. efsa.europa.eu
5PubMed. Re-evaluation of phosphoric acid-phosphates – di-, tri- and polyphosphates (E 338–341, E 343, E 450–452) as food additives and the safety of proposed extension of use, 2019. pubmed.ncbi.nlm.nih.gov
6PubMed. Phosphate Additives in Food—a Health Risk, 2012. pmc.ncbi.nlm.nih.gov

Independently researched6 citations