Magnesium Dihydrogen Diphosphate

About

What it is and where it shows up.

Magnesium dihydrogen diphosphate (MDHDP) is the acidic magnesium salt of diphosphoric acid, appearing as a white powder that is slightly soluble in water. It is used primarily as a raising agent and acidity regulator in bakery products such as self-raising flour, bread, batters, noodles, and processed cereals, and serves as a lower-sodium alternative to sodium acid pyrophosphate.

Safety summary

The regulatory and scientific consensus.

JECFA established a maximum tolerable daily intake (MTDI) of 70 mg/kg body weight for phosphate salts expressed as phosphorus, from all food sources. High dietary phosphate intake can cause osmotic diarrhoea and mild gastrointestinal symptoms at doses around 750 mg/day of phosphorus. Individuals with kidney disease are a sensitive population, as impaired phosphate excretion can lead to hyperphosphataemia.

Regulatory landscape

What food-safety regulators have decided.

Jurisdiction	Status	Note
FSSAI (Food Safety and Standards Authority of India) (India)	Restricted	E546 does not appear as a separately listed additive in the main FSSAI Food Safety and Standards (Food Products Standards and Food Additives) Regulations. Phosphate salts permitted by FSSAI are listed category-by-category; confirmatory status for E546 specifically could not be established with confidence from available sources.source
EFSA (European Food Safety Authority) (European Union)	Approved	Authorised as a raising agent and acidity regulator under Commission Regulation (EU) No 298/2014, amending Annex II to Regulation (EC) No 1333/2008 and specifications in Regulation (EU) No 231/2012. Permitted in food categories including self-raising flour, batters, bread and rolls, noodles, and fine bakery wares. The phosphate group (E 338–341, E 343, E 450–452) was re-evaluated by EFSA in 2019. An MTDI of 70 mg/kg bw/day expressed as phosphorus applies to the phosphate group collectively.source
FDA (Food and Drug Administration) (United States)	Approved	Magnesium pyrophosphate is recognised in the FDA/GINAS substance registry. Phosphate salts are generally recognised as safe (GRAS) when used in accordance with good manufacturing practice. Specific maximum use levels vary by food category under 21 CFR.source

Who should approach with care

Whose guidance would steer them away.

Kidney Disease — Individuals with chronic kidney disease have impaired phosphate excretion; additional dietary phosphate from additives such as E546 can contribute to hyperphosphataemia, a recognised risk factor for cardiovascular complications and bone disease in this population.

Ibs — High phosphate intake (~750 mg/day as phosphorus) can cause osmotic diarrhoea and mild gastrointestinal symptoms in sensitive individuals, including those with irritable bowel syndrome.

Heart Disease — Elevated serum phosphate linked to high dietary phosphate additive consumption has been associated with cardiovascular risk; individuals with existing heart disease should monitor total phosphate intake from food additives including phosphate salts like E546.

Research citations

The sources behind this verdict.

1WHO. Safety evaluation of certain food additives – Magnesium dihydrogen diphosphate (WHO Food Additives Series 67). iris.who.int
2FAO. Magnesium Dihydrogen Diphosphate – Chemical and Technical Assessment (CTA). fao.org
3EFSA. 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
4PubMed. 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 (PMC full text), 2019. pmc.ncbi.nlm.nih.gov
5other. Commission Regulation (EU) No 298/2014 – Authorisation of Magnesium dihydrogen diphosphate as raising agent and acidity regulator, 2014. eur-lex.europa.eu

Independently researched5 citations