Food & Drink / Compounds / Sodium hexametaphosphate (SHMP / Calgon / Graham's salt / E452i)

Sodium hexametaphosphate (SHMP / Calgon / Graham's salt / E452i) in food: ingestion safety

Low risk

(People-specific data is limited; this page draws from human adult context.) Sodium hexametaphosphate (SHMP / Calgon / Graham's salt / E452i) poses low risk to adults under normal use conditions.

What is sodium hexametaphosphate (shmp / calgon / graham's salt / e452i)?

The IUPAC name is potassium 5-formyl-2-methoxyphenolate.

IUPAC name
potassium 5-formyl-2-methoxyphenolate
CAS number
10124-56-8
Molecular formula
C8H7KO3
Molecular weight
190.24 g/mol
SMILES
COC1=C(C=C(C=C1)C=O)[O-].[K+]
PubChem CID
23680567

Risk for people

Low risk

Sodium hexametaphosphate (SHMP / Calgon / Graham's salt / E452i) poses low risk to adults under normal use conditions.

Regulatory consensus

3 regulatory and scientific bodies have classified Sodium hexametaphosphate (SHMP / Calgon / Graham's salt / E452i). The classifications differ — that's the data.

AgencyYearClassificationNotes
FDAGRAS food additive (E452i)
EUE452i — approved food additive; ADI 70 mg/kg/day (as P) for total phosphate additives
EPAPhosphate discharge regulations apply

Regulators apply different standards of evidence — animal-data weighting, exposure-pattern assumptions, epidemiological power thresholds — which is why two scientific bodies can review the same data and reach different conclusions. The disagreement is the data.

Where you encounter sodium hexametaphosphate (shmp / calgon / graham's salt / e452i)

  • Food Processingprocessed cheese (emulsifier), seafood (moisture retention), evaporated milk
  • Oral Caretartar-control toothpaste (Crest Pro-Health), mouthwash
  • Water Treatmentmunicipal water corrosion control, water softening (original Calgon)
  • Industrialceramic deflocculant, paper manufacturing, textile processing

Safer alternatives

Lower-risk approaches that achieve a similar outcome to Sodium hexametaphosphate (SHMP / Calgon / Graham's salt / E452i):

  • Sodium citrate
    Trade-offs: Zeolite A and sodium citrate replace phosphate builders in detergents; comparable cleaning performance at moderate hardness; less effective in very hard water; eliminates eutrophication contribution; widely adopted post-phosphate bans (EU 2013, many US states).
  • Tetrasodium pyrophosphate
    Trade-offs: Removes 95-99% of dissolved contaminants including metals, PFAS, nitrates; wastes 2-4 gallons per gallon produced (improving with newer systems); removes beneficial minerals; $0.05-0.25/gallon; requires pre-treatment for longevity.

Frequently asked questions

What products contain sodium hexametaphosphate (shmp / calgon / graham's salt / e452i)?

Sodium hexametaphosphate (SHMP / Calgon / Graham's salt / E452i) appears in: processed cheese (emulsifier) (food processing); seafood (moisture retention) (food processing); tartar-control toothpaste (Crest Pro-Health) (oral care); mouthwash (oral care); municipal water corrosion control (water treatment).

Why do regulators disagree about sodium hexametaphosphate (shmp / calgon / graham's salt / e452i)?

Sodium hexametaphosphate (SHMP / Calgon / Graham's salt / E452i) has been classified by 3 agencies including FDA, EU, EPA, with differing conclusions. Regulators apply different standards of evidence (animal data weighting, exposure-pattern assumptions, epidemiological power thresholds), which is why two scientific bodies can review the same data and reach different conclusions. See the regulatory consensus table on this page for the full picture.

See Sodium hexametaphosphate (SHMP / Calgon / Graham's salt / E452i) in the food app

Look up products containing sodium hexametaphosphate (shmp / calgon / graham's salt / e452i), compare to alternatives, and explore the full data record.

Open in food View raw API data

Sources (1)

  1. — expert_curation

Reference data, not professional advice. Aggregates publicly available regulatory and scientific data; not a substitute for veterinary, medical, legal, or regulatory advice. Why we built ALETHEIA →