Acids & Salts Available — Bulk Only

Disodium Phosphate (DSP, Sodium Phosphate Dibasic)

DSP
CAS 7558-79-4 · Formula HNa2O4P · MW 141.959 g/mol

An inorganic sodium phosphate buffer used for pH control, emulsification, and scale prevention across food and industrial systems. It is used as a buffering and emulsifying agent in food and industrial systems, as a scale inhibitor in boiler-water treatment, and as a reagent in metal phosphatizing, electroplating, and textile and leather processing.

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HS Code
2835.22
At a Glance
Material Family
Acids & Salts
Record Type
Pure compound
Primary Role
pH Adjustment · Chelation / Sequestration
Solubility
≥ 100 mg/mL at 20 °C
Functional Roles
DISODIUM PHOSPHATE
ANTICORROSIVEBUFFERINGFRAGRANCE
Applications & Use Cases
  • Buffering agent: Controls pH in food, cleaning, and industrial baths.
  • Emulsifier: Emulsifying salt in processed-food systems.
  • Scale inhibitor: Controls scale in boiler-water treatment.
  • Metal treatment: Reagent in phosphatizing and electroplating.
  • Sequestrant: Binds polyvalent metal ions in process water.
Physical Properties
Melting Point
MP: loses H2O at 92.5 °C; Specific gravity: 2.066 at 15 °C /Disodium phosphate dihydrate/
Density
1.8 to 2.5 at 25 °C
Solubility
≥ 100 mg/mL at 20 °C
pH
Between 8,4 and 9,6 (1 % solution)
Safety & Handling
Full SDS available on request

A grade-specific Safety Data Sheet (SDS) — with the complete hazard classification, handling precautions, and transport information — is supplied with every shipment and available on request. Confirm all safety and regulatory details against the SDS for your specific grade.

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HS / Tariff Classification
Harmonized System (HS) Code — 6-digit international heading
2835 . 22
Chapter 28
Inorganic chemicals; compounds of precious metals and rare-earth metals
Heading 28.35
Internationally harmonized (WCO HS)
Subheading 2835.22
6-digit international code — national tariff line adds further digits
Chemical Identity
CAS Number
7558-79-4
Molecular Formula
HNa2O4P
Molecular Weight
141.959 g/mol
IUPAC Name
disodium;hydrogen phosphate
INCI Name
DISODIUM PHOSPHATE
PubChem CID
InChI Key
BNIILDVGGAEEIG-UHFFFAOYSA-L
Synonyms & Trade Names
Sodium phosphate dibasic Disodium hydrogen phosphate DISODIUM PHOSPHATE Disodium hydrogenorthophosphate Acetest Sodium phosphate, dibasic Dibasic sodium phosphate Disodium acid phosphate disodium hydrogenphosphate Exsiccated sodium phosphate Soda phosphate Disodium orthophosphate Phosphoric acid, disodium salt Sodium monohydrogen phosphate Sodium hydrogen phosphate secondary Sodium phosphate Phosphate of soda Disodium phosphate, anhydrous FEMA No. 2398
Full Description

Disodium Phosphate (CAS 7558-79-4) is the disodium salt of phosphoric acid (disodium hydrogen phosphate). It is used as a buffering and emulsifying agent in food and industrial systems, as a scale inhibitor in boiler-water treatment, and as a reagent in metal phosphatizing, electroplating, and textile and leather processing.

Frequently Asked Questions

What is disodium phosphate used for?

Disodium phosphate (DSP, CAS 7558-79-4) is the disodium salt of phosphoric acid, used as a buffering and emulsifying agent in food and industrial systems, a scale inhibitor in boiler-water treatment, and a reagent in metal phosphatizing, electroplating, and textile and leather processing. It also acts as a sequestrant that binds polyvalent metal ions in process water. RawSource supplies it in bulk to industrial and food-grade accounts.

Is disodium phosphate the same as sodium phosphate or dipotassium phosphate?

No. "Sodium phosphate" is a family that includes monosodium, disodium, and trisodium phosphates, each with a distinct CAS and pH behavior; DSP is specifically disodium hydrogen phosphate (CAS 7558-79-4). Dipotassium phosphate is the potassium analog, a different salt entirely. Specify the exact salt and grade when ordering.

What grades of disodium phosphate are available?

DSP is commercially supplied in technical/industrial and food grades, and as anhydrous or hydrated forms (e.g., dihydrate, dodecahydrate) that differ in assay basis. Specify the required grade and hydrate state at quote so the CoA matches your specification. RawSource provides CoA and SDS with each shipment.

What is the CAS number and HS code for disodium phosphate?

The CAS number is 7558-79-4 (formula HNa2O4P for the anhydrous salt) and it classifies under HS 2835.22 (phosphates of mono- or disodium). These identifiers apply to import documentation and CoA verification.

What is the cost of bulk disodium phosphate?

Pricing is quoted by order based on grade, hydrate form, volume, packaging (bags, drums, totes), and freight. Send RawSource your target quantity, grade, and destination for a landed quote and lead time. We quote rather than list because cost tracks phosphate markets and scale.

Disclaimer. Information on this page — including properties, identifiers, hazard, transport (DOT/UN) and tariff (HS) classifications, and applications — is provided for general reference and is compiled from authoritative public sources (e.g. PubChem/ECHA, 49 CFR 172.101, the Harmonized Tariff Schedule). Values are typical and are not a guaranteed specification; the Certificate of Analysis (CoA) for the lot purchased governs. Products are sold for industrial and professional use only. Nothing here is a medical, health, or efficacy claim or advice. Always consult the current Safety Data Sheet (SDS) before handling, storage, transport or disposal, and confirm regulatory status, classification and suitability for your application and jurisdiction. Hazard, transport and tariff classifications must be verified for your specific shipment. RawSource makes no warranty, express or implied, and assumes no liability for use of this information. Trademarks. Third-party trademarks and brand names are the property of their respective owners; any reference is nominative — used only to identify a comparable product — and does not imply affiliation with, sponsorship by, or endorsement by the trademark owner.