Phosphoric acid(food grade) CAS：7664-38-2
Versatile Acidulant: Delivers precise pH adjustment across food systems such as carbonated beverages and dairy products.
High Purity & Safety: Complies with stringent FDA/GB food-grade standards and contains minimal heavy-metal impurities.
Effective Sanitization: At 10–15% concentration, it provides powerful cleaning and disinfection for food processing equipment.
Controlled Viscosity: The syrupy consistency of its 85% solution ensures accurate dosing in industrial food preparation.
Cross-Industry Utility: Applicable to metal surface treatment, electronics manufacturing, and specialty chemical synthesis.
Phosphoric Acid (H₃PO₄) – Physical-Chemical Profile
In its pure state—commonly called orthophosphoric acid—it appears as a colorless, viscous liquid or transparent orthorhombic crystalline solid, odorless, with a sharply acidic taste. The standard commercial grade is an 85% aqueous solution, which is a clear, slightly viscous, syrup-like liquid.
Key Physical Data: Pure acid melts at 42.35°C with a relative density of 1.834; the 85% solution has a specific gravity of about 1.70, and is a non-volatile, high-boiling acid.
Solubility: Completely miscible with water in all proportions and readily soluble in ethanol.
Thermal Transformation: Upon heating to 213°C, it undergoes partial dehydration to pyrophosphoric acid; further heating to approximately 300°C converts it into metaphosphoric acid.
Phosphoric Acid (H₃PO₄) — Technical Specifications
| Parameter | Value |
|---|---|
| Melting Point (pure) | 42.35°C |
| Boiling Point | 158°C (decomposition) |
| Density (25°C, pure) | 1.834 g/cm³ |
| Viscosity (85% sol., 25°C) | 147 cP |
| Acidity Constants | pKa₁ = 2.14, pKa₂ = 7.20, pKa₃ = 12.67 |
| Refractive Index (85%) | 1.342 |
| Thermal Decomposition | 213°C → Pyrophosphoric acid, 300°C → Metaphosphoric acid |
Industrial Applications of Phosphoric Acid (H₃PO₄)
1. Food & Beverage Industry — Acidity Regulator & Nutrient Source
Food-grade phosphoric acid (E338) is widely used as an acidifying agent in carbonated beverages (particularly colas), fruit jams, and processed foods to impart a sharp, tangy taste. It also serves as a yeast nutrient in fermentation processes and as a clarifier in sugar refining, where it acts as an organic reaction catalyst. In dairy, brewing, and food processing industries, it is also commonly employed as an effective disinfectant and cleaning agent for equipment.
2. Metal Surface Treatment — Phosphating, Rust Removal & Electropolishing
Industrial-grade phosphoric acid is a cornerstone chemical in metal surface engineering. It is used to apply phosphate conversion coatings on steel surfaces, forming a tightly adherent, insoluble phosphate film that provides corrosion protection and enhances paint adhesion. It serves as an effective rust remover and rust converter by converting reddish-brown iron(III) oxide (rust) into black ferric phosphate. When blended with nitric acid, phosphoric acid is used as a chemical polishing agent for aluminum and aluminum alloys, significantly improving surface smoothness and luster. Additionally, it functions as an electropolishing solution to achieve mirror-like finishes on precision metal parts.
3. Electronics & Semiconductor — High-Purity Cleaning & Etching
Electronic-grade phosphoric acid is a high-purity chemical reagent (with impurity levels as low as 10⁻⁹) essential for wet etching and precision cleaning in the microelectronics industry. It is widely used in the manufacturing of ultra-large-scale integrated circuits (ULSI) and thin-film transistor liquid crystal displays (TFT-LCD). Specific applications involve silicon wafer cleaning prior to photoresist coating, etching of insulating films, semiconductor films, and conductor films during the photolithography process, and final photoresist stripping after pattern transfer. The purity level directly determines the yield, electrical performance, and reliability of electronic components.
4. Fertilizer Production — Intermediate for Phosphate Fertilizers
Phosphoric acid is the most important intermediate in the global phosphate fertilizer industry, with approximately 85% of the world's phosphate fertilizer production relying on phosphoric acid as the process intermediate. It is primarily used to manufacture ammonium phosphates such as monoammonium phosphate (MAP) and diammonium phosphate (DAP), which are produced by reacting phosphoric acid with ammonia. It is also a key raw material for producing triple superphosphate (TSP), a high-analysis phosphorus fertilizer. The wet-process phosphoric acid route (reacting phosphate rock with sulfuric acid) dominates global production.
5. Animal Feed — Phosphorus & Calcium Supplement
Feed-grade phosphoric acid is used as a raw material to produce feed phosphate salts, including monocalcium phosphate (MCP), dicalcium phosphate (DCP), and tricalcium phosphate (TCP). These compounds serve as highly bioavailable phosphorus and calcium supplements in livestock, poultry, and aquaculture feed formulations, supporting skeletal development, energy metabolism (ATP formation), and reproductive performance. Feed phosphates help prevent deficiency-related diseases such as rickets, osteomalacia, and anemia, while promoting growth rates and egg production in laying hens. The typical inclusion rate of dicalcium phosphate in feed formulations ranges from 1.0% to 2.5%, and phosphorus from high-quality feed phosphates can achieve utilization rates of 95%–100% in animals.
Phosphoric Acid – Packaging & Storage Specifications
Packaging Configurations
| Format | Capacity | Material | Application / Remarks |
|---|---|---|---|
| Carboys / Jerricans | 30 L | HDPE with tamper‑evident cap | Small‑lot supply of food‑grade or electronic‑grade; tamper‑proof cap for transport security |
| Drums | 250 L | Polyethylene‑lined steel | Industrial‑grade bulk packaging; inner lining prevents corrosion and leakage |
| ISO Tank Containers | 25,000 L | 316L stainless steel | Mass bulk shipment for food‑grade and industrial‑grade; suitable for terminal‑to‑plant transfer |
Storage & Handling Guidelines
Storage Conditions: Keep in a cool, dry, well‑ventilated area, away from alkalis, metal powders, reducing agents and organic materials.
Temperature Control: 85% phosphoric acid solution should be stored above -20°C to prevent freezing; pure acid storage temperature should be maintained at 25–40°C to avoid solidification (M.P. 42.35°C).
Seal Integrity: Close containers immediately after use to prevent moisture absorption and vapor accumulation.
Material Compatibility: HDPE and polypropylene (PP) are suitable for short‑term contact; 316L stainless steel or PTFE‑lined equipment is recommended for long‑term or elevated‑temperature service.
Safety Precautions: Wear acid‑resistant gloves, goggles, and protective clothing during handling. Emergency eyewash and safety shower must be available on site.
