Phosphoric Acid (85%)

CAS Number:

7664-38-2

Chemical Name: 

Phosphoric Acid (Orthophosphoric Acid)

Common Concentration:

85% (by weight) in water is the standard technical and food-grade concentration

Molecular Formula:

H3PO4

Molecular Weight:

98.00 g/mol (anhydrous)

Common Form:

Clear, colorless, odorless, syrupy liquid

Uses:

Phosphoric acid is a strong, non-volatile, inorganic acid with triple acidity. Its 85% concentration is the workhorse grade for industrial and food applications due to its stability and handling properties.

Primary Applications:

· Fertilizer Industry (>90% of global use): Raw material for producing phosphate fertilizers (e.g., ammonium phosphates, superphosphates).

· Food & Beverage Industry (E338): Acidulant and pH adjuster in cola beverages, jams, processed meats, and cheese. Provides a sharp, sour taste.

· Metal Treatment & Cleaning: Key component in solutions for rust removal, phosphating (creating a corrosion-resistant coating on steel), and metal cleaning/pickling.

· Water Treatment: Used for pH adjustment/correction and as a sequestrant to control scale (e.g., in potable water systems).

· Chemical Manufacturing: Precursor to other phosphate compounds like sodium phosphates (STPP, etc.), and used in catalysts, dyes, and fire retardants.

· Dentistry: Etching agent for tooth enamel in dental procedures.

What does Phosphoric Acid (85%) do in a formulation?

• Acidulant & pH Controller: Provides a strongly acidic medium (pH of 85% solution is <1.0; 1% solution ~1.5). Its non-volatile nature makes it ideal for long-term pH control
• Sequestering Agent: Binds metal ions like calcium and magnesium, preventing precipitation and scale formation.
• Catalyst: Used as an acid catalyst in organic synthesis (e.g., petroleum alkylation)
• Etchant & Cleaning Agent: Reacts with metal oxides to dissolve rust and etches surfaces for better adhesion
• Flavor Enhancer: Imparts a characteristic tartness in foods and beverages.
• Nutrient Source: Provides phosphorus in fertilizers and some food fortification.

Safety Profile:

· Hazard Classification: Danger. Causes severe skin burns and eye damage. May be corrosive to metals.

· Skin/Eye Contact: Extremely corrosive. Causes immediate tissue damage and severe chemical burns. Flush immediately with plenty of water for at least 15-20 minutes and seek medical attention.

· Inhalation: Mist or vapors from hot solutions can irritate the nose, throat, and respiratory tract, causing coughing and shortness of breath.

· Ingestion: Highly corrosive. Can cause severe burns of the mouth, throat, and stomach, with potential for perforation. Do NOT induce vomiting.

· Required PPE: Chemical-resistant gloves (e.g., neoprene, nitrile), splash goggles or face shield, acid-resistant apron or clothing, and adequate ventilation.

· Handling Note: ALWAYS add acid to water slowly with stirring, NEVER water to acid, to prevent violent exothermic reaction and splattering of concentrated acid. Store away from bases and metals.

Technical profile: