Monosodium phosphate

Description

Monosodium phosphate is identified by CAS 7558-80-7, molecular formula H2NaO4P and molecular weight 119.96 g/mol. UNII KH7I04HPUU; ChEBI 37585; InChIKey AJPJDKMHJJGVTQ-UHFFFAOYSA-M. Melting Point: 200 °C (decomposes); Solubility: 121; Density: 2360 kg/cu m.

Identification

CAS Registry Number	7558-80-7
PubChem CID	23672064
Molecular formula	H2NaO4P
Molecular weight	119.96 g/mol
IUPAC name	sodium dihydrogen phosphate
InChIKey	AJPJDKMHJJGVTQ-UHFFFAOYSA-M
UNII (FDA)	KH7I04HPUU
ChEBI ID	CHEBI:37585

Computed Descriptors

Molecular Weight	119.977
Hydrogen Bond Donor Count	2
Hydrogen Bond Acceptor Count	4
Rotatable Bond Count	0
Exact Mass	119.95883982
Monoisotopic Mass	119.95883982
Topological Polar Surface Area	80.6
Heavy Atom Count	6
Formal Charge	0
Complexity	61.9

Physical & Chemical Properties

Melting Point	200 °C (decomposes)
Solubility	121
Density	2360 kg/cu m

Physical description & handling notes

• Dry Powder; Other Solid; Large Crystals; CBI; Liquid; Liquid; Other Solid
• A white odourless, slightly deliquescent powder, crystals or granules
• Colorless or white solid; Slightly hygroscopic; [Hawley] White powder; [MSDSonline]
• Colorless, monoclinic crystals
• White crystalline powder
• Odorless

Regulatory Status

Regulatory & Food Contact

FDA Substance added to food: ANTICAKING AGENT OR FREE-FLOW AGENT, ANTIMICROBIAL AGENT, DRYING AGENT, EMULSIFI FDA Inventory of Food Contact Substances Listed in 21 CFR: FCS ACIDITY_REGULATOR; SEQUESTRANT: Food Additives ANTICAKING AGENT OR FREE-FLOW AGENT, ANTIMICROBIAL AGENT, DRYING AGENT, EMULSIFIER OR EMULSIFIER SALT, FLAVOR Group MTDI for phosphorus from all sources, expressed as P TRS 683-JECFA 26/25

GHS notification summary

89% (597 / 671)

GHS Hazard Classification

GHS notification summary	89% (597 / 671)
Reported hazard statements	H319 (11%)

Documented Uses

• Used as a pH buffer (baking powders, fleet enema solutions, electroplating baths, and acid cleaners), sequestrant for foods, emulsifier, laboratory reagent, metal phosphatising reagent, and textile dyeing/printing auxiliary; Also used to treat boiler water and wastewater, remove halogen from waste gases, supplement animal feed, and acidify urine; [HSDB]
• Acid and Alkali Cleaning of Metals [Category: Clean]
• Electroplating [Category: Plate]
• Sewer and Wastewater Treatment [Category: Industry]
• Textiles (Printing, Dyeing, or Finishing) [Category: Industry]
• Farming (Feed Additives) [Category: Industry]

Synonyms

7558-80-7; Monosodium phosphate; SODIUM DIHYDROGEN PHOSPHATE; Sodium acid phosphate; Sodium phosphate, monobasic; Sodium primary phosphate; Acid sodium phosphate; Monosodium monophosphate; Monobasic sodium phosphate; Monosodium dihydrogen orthophosphate; Monosodium phosphate, anhydrous; Monosodium orthophosphate; Monosorb XP-4; Primary sodium phosphate; Sodium dihydrogen phosphate, anhydrous; Sodium phosphate (Na(H2PO4))

Frequently Asked Questions

What are the CAS number and molecular formula of Monosodium phosphate?

CAS 7558-80-7; molecular formula H2NaO4P; molecular weight 119.96 g/mol.

What other names is Monosodium phosphate known by?

7558-80-7, Monosodium phosphate, SODIUM DIHYDROGEN PHOSPHATE, Sodium acid phosphate, Sodium phosphate, monobasic, Sodium primary phosphate.

What is the regulatory status of Monosodium phosphate?

Documented regulatory listings: FDA Substance added to food: ANTICAKING AGENT OR FREE-FLOW AGENT, ANTIMICROBIAL AGENT, DRYING AGENT, EMULSIFI; FDA Inventory of Food Contact Substances Listed in 21 CFR: FCS; ACIDITY_REGULATOR; SEQUESTRANT: Food Additives.

Is Monosodium phosphate classified as hazardous?

89% of GHS notifications report no hazard classification (597 of 671).

What are the key physical properties of Monosodium phosphate?

Melting Point: 200 °C (decomposes); Solubility: 121; Density: 2360 kg/cu m.

Facts on this page are taken from PubChem (US National Library of Medicine) and Wikidata. Grade-specific data — assay, moisture, particle size, packaging, shelf life — is issued per batch on the COA and is not published here.