Monosodium phosphate
CAS 7558-80-7
EC 231-449-2
Formula H3O4P.Na
MW 119.98 g/mol
Salts & Minerals Food & NutritionPharmaceuticals & HealthcareWater Treatment Chelation & SequestrationpH Regulation & BufferingAntioxidant & Stabilizer
Description
Monosodium phosphate (CAS 7558-80-7), also known as NaH2PO4, primary sodium phosphate, and acid sodium phosphate, is an inorganic phosphate salt carrying the E-number E339(i). It is the monosodium form of phosphoric acid and is distinguished from di- and trisodium phosphate by its acidic pH profile in solution.
In food and beverage production, NaH2PO4 functions as a buffering agent by donating or accepting protons to maintain target pH ranges during processing. In water treatment, it sequesters calcium and magnesium ions through chelation, preventing scale formation in distribution systems. Pharmaceutical formulators use it to establish and stabilise pH in parenteral and topical preparations.
Monosodium phosphate is available in food-grade (E339i), FCC, and Ph.Eur.-compliant grades. It is supplied as anhydrous or monohydrate powder and falls under REACH registration obligations within the EU. Standard packaging includes 25 kg bags, with bulk options available on request.
In food and beverage production, NaH2PO4 functions as a buffering agent by donating or accepting protons to maintain target pH ranges during processing. In water treatment, it sequesters calcium and magnesium ions through chelation, preventing scale formation in distribution systems. Pharmaceutical formulators use it to establish and stabilise pH in parenteral and topical preparations.
Monosodium phosphate is available in food-grade (E339i), FCC, and Ph.Eur.-compliant grades. It is supplied as anhydrous or monohydrate powder and falls under REACH registration obligations within the EU. Standard packaging includes 25 kg bags, with bulk options available on request.
Physical Properties
| Melting Point | 60 °C |
| Boiling Point | 100°C |
| Density | 1.40 g/mL at 20 °C |
| Appearance | White, slightly deliquescent crystals or granules. |
| Color | White |
| Odor | at 100.00?%. odorless |
| Form | powder |
| Water Solubility | Soluble in water. Insoluble in alcohol,ether and chloroform. |
| Vapor Pressure | 0Pa@20°C |
| pH | 4.0 - 4.5 (25℃, 50g/L in water) |
| Log P | -2.148 (est) |
Safety & Handling (Learn More)
Warning GHS07
H
H319
P
P280P264+P265P337+P317P305+P351+P338
Trade & Regulatory
| HS Code | 28352200 |
| Storage Class | 13 - Non Combustible Solids |
| WGK (Germany) | 1 |
Other Names
Sodium phosphate monobasicsodium dihydrogen phosphateE339iE339(i)NaH2PO4MSPmonosorbxp-4acidsodiumphosphate
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Raw Materials
Derivatives
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