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Chemical substance record

Sodium diphosphate

7722-88-54Na.O7P2265.901 g/mol
Salt and Compound WithChEBI source record

An inorganic sodium salt comprised of a diphosphate(4−) anion and four sodium(1+) cations. More commonly known as tetrasodium pyrophosphate, it finds much use in the food industry as an emulsifier and in dental hygiene as a calcium-chelating salt. — ChEBI

Safety references

Safety documents & references

2 indexed references
US · NIOSH

Occupational chemical safety guide

Tetrasodium pyrophosphate

Read official guide
JP · NITE

Government GHS classification

R05-C-031-JNIOSH, MOE · FY2023

View classification

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Safety guides and government classification records are not a manufacturer’s SDS. Match supplier, product number, concentration, physical form, region and revision before using a document.

Identity & molecular properties

Source-linked values
CAS number7722-88-5ChEBI ↗
Molecular formula4Na.O7P2ChEBI ↗
Molar mass265.901 g/molChEBI ↗
Monoisotopic mass265.871 DaChEBI ↗
Formal charge0ChEBI ↗
ChEBI identifierCHEBI:71240ChEBI ↗

Names & structural identifiers

Copy any identifier
sodium diphosphate
sodium diphosphate
FQENQNTWSFEDLI-UHFFFAOYSA-J
O=P([O-])([O-])OP(=O)([O-])[O-].[Na+].[Na+].[Na+].[Na+]
InChI=1S/4Na.H4O7P2/c;;;;1-8(2,3)7-9(4,5)6/h;;;;(H2,1,2,3)(H2,4,5,6)/q4*+1;/p-4

Classification & relationships

ChEBI ontology

Roles recorded in ChEBI

chelatorfood emulsifierfood thickening agent

Database role annotations describe reported biological or chemical roles; they are not product approvals or recommendations for use.

Safety classification · Japan

NITE / Japanese government
Japan · FY2023 source classification
Tetrasodium oxybisphosphonate · R05-C-031-JNIOSH, MOE
EndpointReported classification
Serious eye damage/eye irritationCategory 1

Selected source-reported endpoints. Other endpoints, rationales and conditions remain in the original classification. Missing or unlisted information does not mean non-hazardous. This is not a global classification or transport decision.

Read the original NITE classification

Mass ↔ amount of substance

Calculated from sourced mass
Equivalent amount
0.0037608 mol

Uses 265.901 g/mol from ChEBI. Assumes the substance described by this record; no purity or concentration correction is applied.

Research & patent references

Selected source associations

Sources & record history

Checked 27 Sep 2026
EMBL-EBI ChEBI · CHEBI:71240

Release 255, 9 September 2026. ChEBI three-star (manually annotated) source entry. View original record ↗ · CC BY 4.0

PubCAS formats source data, connects references and computes explicitly labelled conversions. CAS cross-references are supplied by ChEBI; they do not constitute CAS verification or endorsement.