Phosphoric acid is unusual because it sits comfortably in both industrial and food-related supply chains. The molecule is the same, but the purity requirements are not. A metal-treatment buyer and a food-processing buyer cannot treat the same drum as equivalent.
Supreme Petro Chemicals supplies industrial phosphoric acid from Chennai, with food-grade availability on inquiry. This guide explains the main uses and the grade decisions buyers need to make.
What Is Phosphoric Acid?
Phosphoric acid has CAS number 7664-38-2 and molecular formula H3PO4. It is a colourless, viscous liquid. 85% is the standard industrial concentration commonly requested by manufacturers.
Food-grade phosphoric acid requires tighter impurity control, especially heavy metals. Typical requirements include arsenic below 3 ppm and lead below 1 ppm, subject to the applicable food standard and buyer specification.
Industrial Applications
- Metal treatment: Used for rust removal. It reacts with iron oxide to form iron phosphate, creating a more stable protective layer.
- Phosphating: Used in steel treatment before painting or powder coating to improve adhesion and corrosion resistance.
- Fertilizers: Used in diammonium phosphate (DAP) and monoammonium phosphate (MAP) production.
- Detergents: Used in phosphate-based cleaning compounds, though phosphate use is restricted in many countries because of environmental concerns.
- Water treatment: Used as a corrosion inhibitor in pipelines and to help reduce scale in selected systems.
- Chemical synthesis: Used as a catalyst in some esterification and dehydration reactions.
Food and Pharma Grade
Food-grade phosphoric acid is used as an acidulant in soft drinks, including the characteristic tartness associated with cola beverages. It is also used for pH control in jams and processed foods, subject to food regulations and approved limits.
In dentistry, phosphoric acid is used as an etchant. These applications require the correct grade and compliance standard. Food-grade material should meet applicable requirements such as IS:267 or FSSAI standards for Indian food applications.
Industrial vs Food Grade — Don't Substitute
Never use industrial-grade phosphoric acid in food applications. The critical differentiator is impurity control, especially heavy metals. Industrial material may perform well for rust removal or phosphating but still be unsuitable for food, beverage, or pharma use.
SPC Supply Details
SPC supplies industrial 85% phosphoric acid in carboys and drums. Food-grade phosphoric acid is available on inquiry depending on current stock and documentation requirements. SPC serves buyers in Chennai, Tamil Nadu, and across South India.
Get a Phosphoric Acid Quote
For phosphoric acid requirements, share grade, concentration, quantity, packaging, and destination. Call or WhatsApp our enquiry desk at +91 86087 80096, email Admin@supremepetrochemicals.com, or use the SPC enquiry form.
Grades & Packaging
Phosphoric acid is traded internationally under a small number of well-established commercial grades. The values below are general chemistry and trade facts rather than an SPC-specific specification sheet, since no published spec data for this product is currently on file.
- CAS number: 7664-38-2
- Molecular formula: H3PO4 (orthophosphoric acid)
- Common commercial grades: industrial/technical grade, food grade (meeting FCC or FSSAI-type requirements), and pharmacopoeial grade for specialised uses
- Physical form: colourless to pale, viscous, non-flammable liquid
- Typical industrial packaging: HDPE carboys and drums, chosen for corrosion resistance rather than mild steel
- Bulk packaging: IBC totes and tanker loads for higher-consumption buyers
- Grade discipline: food-grade and industrial-grade material are not interchangeable; confirm the grade and request supporting documentation (CoA/SDS) before use
FAQ
What is the CAS number and formula of phosphoric acid?
Phosphoric acid is CAS number 7664-38-2, molecular formula H3PO4. It is also known as orthophosphoric acid. Quoting the CAS number on a purchase order helps avoid confusion with other phosphate-based products.
What packaging does SPC supply phosphoric acid in, and can food grade be sourced too?
Industrial phosphoric acid is supplied in carboys and drums, with IBC and bulk options available for larger requirements. Food-grade material is available on enquiry, subject to current stock and documentation requirements, and should never be substituted with industrial-grade material.
How do I get a phosphoric acid quote from SPC?
Share the required grade, concentration, quantity, packaging preference and delivery location via the contact page. Quotes are typically answered within 4 working hours, Monday to Saturday.