Phosphoric acid
CAS 7664-38-2H3O4P97.995 g/mol
Phosphoric acid is a phosphorus oxoacid that consists of one oxo and three hydroxy groups joined covalently to a central phosphorus atom. It has a role as a NMR chemical shift reference compound, a fertilizer, a solvent, a human metabolite and an algal metabolite. It is a conjugate acid of a phosphate ion and a dihydrogenphosphate.
IUPAC: phosphoric acid
PubChem
Physical & Chemical Properties
| Melting Point | 108 °F (NIOSH, 2024) |
| Boiling Point | greater than 266 °F at 760 mmHg (USCG, 1999) |
| Density | 1.892 at 77 °F (USCG, 1999) - Denser than water; will sink |
| Solubility | Miscible (NIOSH, 2024) |
| Vapor Pressure | 0.03 mmHg (NIOSH, 2024) |
| pH | pH = 1.5 (0.1 N aqueous solution) |
| Appearance | Phosphoric acid appears as a clear colorless liquid or transparent crystalline solid. The pure solid melts at 42.35 °C and has a density of 1.834 g / cm3. Liquid is usually an 85% aqueous solution. Shipped as both a solid and liquid. Corrosive to metals and tissue. Used in making fertilizers and detergents and in food processing. |
Data: PubChem · Last updated: 4/20/2026
GHS Classification
No GHS classification data available.
Classification data is sourced from ECHA.
Regulatory Compliance
TSCA
Listed
note: Status based on EPA TSCA Active Inventory · inventory name: TSCA Chemical Substance Inventory
View sourceGlobal Trade Intelligence
No trade flow data available for this chemical.
HS Code(s): 2809
Data: UN Comtrade
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