Phosphoric Acid
Phosphoric acid 75% and 85% — fertilizer, technical and food grade, used in fertilizer manufacture, metal treatment and food acidulation. Grades are not interchangeable.
75% / 85% H3PO4 CAS 7664-38-2 Clear
Industry information — not currently offered
Phosphoric acid is the intermediate from which every concentrated phosphate fertilizer is made. Fertilizer-grade acid at 75% P2O5 goes into TSP, MAP and DAP production; technical and food grades are purified further and serve entirely different industries.
The distinction between grades is the thing that matters commercially and legally. Fertilizer grade contains impurities that are irrelevant in a bag of DAP and unacceptable in a food or beverage application. Technical grade is specified for metal phosphating, water treatment and catalyst manufacture. Food grade must meet a monograph — in the EU, E338 — and carries the documentation to prove it.
Phosphoric acid is classified as a corrosive dangerous good for sea transport, which changes the packaging, the freight and the ports that will accept it. It is not a product to quote casually.
Grades that are actually traded
The nominal grade is the headline. What a buyer can actually order is the set of grades the market quotes, and they are not interchangeable on price or on analysis:
- 75% fertilizer grade
- 85% technical grade
- 85% food grade
Availability of any specific grade is confirmed per order against the production schedule. A grade that is quoted today is not a grade that is in stock.
Specification
The table below gives the nominal analysis and the parameters that a buyer should write into the contract. Values that depend on the production lot are not printed as numbers here, because a number on a website is not a guarantee — the lot COA is.
| Parameter | Value |
|---|---|
| H3PO4 concentration | 75% or 85%, as ordered |
| P2O5 content | Confirmed per lot — see TDS / COA Calculated from the assay and stated on the COA |
| Colour and clarity | Confirmed per lot — see TDS / COA |
| Sulphate, chloride, fluoride | Confirmed per lot — see TDS / COA Limits are grade-dependent — a food grade and a fertilizer grade are not tested to the same numbers |
| Heavy metals (as Pb) | Confirmed per lot — see TDS / COA Food grade only, against the applicable monograph |
| Specific gravity | Confirmed per lot — see TDS / COA |
Typical values describe the grade as it is normally traded. The guaranteed analysis for your order is the one stated on the certificate of analysis issued for the production lot, and it is confirmed in the sales contract before shipment.
Reference only: This product is described so buyers can understand the grade and where it sits in the phosphate chain. We do not currently offer it, and no quotation entry point is provided on this page.
Applications
- Phosphate fertilizer manufacture
- Metal phosphating and surface treatment
- Water treatment and pH adjustment
- Food and beverage acidulation (food grade only)
Why this product, and not the one next to it
The upstream phosphate
Every concentrated phosphate fertilizer is built on phosphoric acid, so its price sets the floor under TSP, MAP and DAP.
Grades that are genuinely different
Fertilizer, technical and food grades are separate products with separate purification and separate documentation, not one product sold under three labels.
High concentration
85% acid delivers more P2O5 per tonne of freight than any solid phosphate, which is why it moves as acid rather than as salt where the process allows.
Packaging options
- IBC totes (typically 1000–1250 kg)
- ISO tanks, for full parcels
- Drums, for smaller quantities
Loading quantity depends on packaging, container type and the weight limit of the destination country. It is confirmed per order. The bag type, bag weight, liner and marks are stated on the quotation so that two offers can be compared on the same basis.
Quality documentation
- Certificate of analysis for the production lot
- Material safety data sheet
- UN 1805 dangerous goods declaration
- Food-grade conformity documentation, where food grade is ordered
Documents are issued on a per-shipment basis. Certification availability is confirmed for each order before contract.
Export considerations
Phosphoric acid is a Class 8 corrosive dangerous good under UN 1805. It requires dangerous goods documentation, approved packaging and a carrier that accepts the class. This is not a cargo to book as general goods.
Food grade must be ordered as food grade and documented as food grade. Fertilizer grade cannot be upgraded by paperwork, and substituting one for the other is a compliance failure for the buyer as well as the seller.
This product is described for reference. We do not currently offer phosphoric acid, and no quotation entry point is provided on this page.
Export regulations and import requirements can change. This is a general overview written for buyers, not a substitute for confirming current requirements with your customs broker and with our export team before you commit to a shipment.
Questions buyers ask about H3PO4
Do you supply phosphoric acid?
Not at present. The page explains the grades because buyers working on phosphate compounds need to understand where the acid sits in the chain. For acid supply we can point you to a specialist rather than quote it ourselves.
What is the difference between 75% and 85% acid?
Concentration and end use. 75% P2O5 acid is the fertilizer-grade concentration used in phosphate fertilizer production. 85% H3PO4 is the concentration normally traded for technical and food applications. They are quoted on different assay bases, so the two figures are not directly comparable.
Compared with
Comparing two offers on the same cargo?
Send both specifications and we will tell you where they genuinely differ — basis of analysis, granule size, packaging, loaded quantity — and where the difference is only presentation.