E450 – Diphosphates - Food additives database

Safety grading ORANGE – SOME CONCERNS

Why ORANGE? E450 is the E-number for diphosphates (also called pyrophosphates), a family of inorganic phosphate salts used to control acidity, improve texture, and stabilise moisture in many processed foods. Regulators generally consider phosphate additives to have low acute toxicity and no meaningful genotoxic or carcinogenic concern at authorised uses. However, phosphate additives also contribute to overall dietary phosphorus exposure, and that is where the main controversy sits.

The European Food Safety Authority (EFSA) re-evaluated phosphoric acid and phosphate salts (including E450) and set a group ADI (Acceptable Daily Intake) of 40 mg/kg body weight per day, expressed as phosphorus. EFSA also noted that in some exposure scenarios, estimated intakes could exceed this group ADI for infants, toddlers, children and adolescents, especially for high consumers and when supplements are included on top of food intake. This does not automatically mean harm, but it is a clear signal that exposure management matters for certain groups and dietary patterns.

Independent studies show that phosphate additives can increase daily phosphorus intake compared with comparable diets without additive phosphates. Controlled feeding research has reported short-term changes in mineral-metabolism hormones after additive-rich diets. This matters most for people with reduced kidney function.

Because E450 is legally permitted and the toxicology database is broadly reassuring, it does not meet the threshold for RED. But because credible evidence indicates that phosphate additives can push total phosphorus exposure higher, and because regulators have flagged potential ADI exceedance in certain population groups, E450 fits best as ORANGE: safe for most people at typical intakes, but with credible concerns around cumulative exposure and vulnerable groups.

People with chronic kidney disease (CKD), dialysis patients, or anyone on a medically prescribed low-phosphate diet should treat phosphate additives (including diphosphates) as a meaningful source of dietary phosphate. For healthy adults who eat a mostly minimally processed diet, occasional exposure is unlikely to be a major risk driver. The practical risk scenario is frequent intake of additive-heavy foods combined with other phosphate sources.

Should You Avoid E450?

You do not need to avoid E450 completely if you are generally healthy. The more useful strategy is to manage frequency: diphosphates show up most often in ultra-processed foods that are easy to overconsume.

Consider limiting if your diet relies heavily on processed meats, packaged bakery products, and ready meals.
Actively avoid or tightly limit if you have CKD, hyperphosphatemia, are on dialysis, or have been advised to restrict phosphate.
Check supplements and sports products, as phosphate exposure from supplements can stack on top of food exposure.

Common Uses

Baking powders and self-raising flour – helps control leavening reactions and dough performance.
Cakes, biscuits, pancakes, waffles – supports texture, volume, and consistent rise.
Processed meats (sausages, ham, deli slices) – improves water retention, sliceability, and mouthfeel.
Seafood and restructured fish products – helps bind water and stabilise texture.
Processed cheese and cheese sauces – improves melt, emulsification, and stability.
Instant mixes and powdered products – supports flow, dispersion, and rehydration behaviour.

Common names / Synonyms

Diphosphates
Pyrophosphates
Sodium acid pyrophosphate (SAPP)
Disodium diphosphate / disodium pyrophosphate
Tetrasodium diphosphate / tetrasodium pyrophosphate
Tetrapotassium diphosphate / tetrapotassium pyrophosphate
Calcium diphosphate / calcium pyrophosphate

On ingredient lists you may also see specific subtypes written as E450(i), E450(ii), and similar, depending on the exact salt used.

What is it?

Diphosphates are condensed phosphate salts built around the P₂O₇⁴⁻ (pyrophosphate) group. In food technology they are valued because they are multifunctional: they can buffer acidity, bind minerals, influence protein behaviour, and stabilise emulsions. This combination helps manufacturers achieve consistent texture and shelf performance across large-scale production.

Commercial “E450” is not a single compound. It is a family of food-grade salts (typically sodium, potassium, calcium, or magnesium diphosphates) chosen for solubility and function. In bakery systems, certain diphosphates are used in leavening systems to control how quickly carbon dioxide is released, which improves rise and crumb texture. In meat and seafood, diphosphates can increase water-holding capacity by affecting ionic strength and interactions between proteins, helping products stay juicy and slice cleanly. In processed cheese and sauces, phosphate salts can help emulsify fat and water phases to keep products smooth.

How it is produced: Industrial production typically starts from food-grade phosphoric acid or purified orthophosphates. After neutralisation, producers heat the material to condense two phosphate units into pyrophosphate (diphosphate). The final product is dried, milled, and standardised to food additive specifications.

Because diphosphates are a concentrated, highly absorbable form of inorganic phosphate, the key debate is less about classic toxicity and more about cumulative dietary load, especially in populations with high processed-food intake or reduced renal clearance.

Where it’s allowed (EU vs US)

EU: Diphosphates (E450) are authorised food additives under EU rules on food additives, including the relevant annexes to Regulation (EC) No 1333/2008 as amended.

US: Several phosphate salts used in foods (including sodium acid pyrophosphate) are permitted, and some are listed as GRAS (Generally Recognized as Safe) when used in accordance with good manufacturing practice.

E450 – Diphosphates