Phosphoric Acid H₃PO₄ 85% (Technical & Food Grade) — Bulk Supply & COA 2026

What is H3PO4? Actual Technical Specifications

H3PO4 (Phosphoric Acid, CAS 7664-38-2) is a triprotic inorganic acid, commonly available on the industrial market as an 85% concentration solution. It is an important intermediate chemical in the fertilizer, food, and metal surface treatment production chains — not as strongly corrosive as concentrated HCl or H2SO4, but still requiring strict safety controls during storage and large-volume transport.

In its 100% pure form, H3PO4 is a crystalline solid with a melting point of 21°C. On the industrial market, H3PO4 is always supplied in solution form (typically 75%, 80%, 85%) because the solid form is difficult to store and transport. Loc Thien supplies H3PO4 85% directly — the most common concentration for all three application groups: fertilizer, food, and surface treatment.

H3PO4 85% Technical Specifications Table (based on actual COA of Loc Thien’s shipments):

The 85% content is the core quality indicator to check on every shipment — H3PO4 below this threshold (due to dilution or contamination) throws off the entire blending formula at NPK plants, or fails to meet pH adjustment requirements in the food industry. For every shipment, Loc Thien provides a COA showing the actual content and a Vietnamese-language MSDS sent upon request.

Industrial Applications of H3PO4

NPK, DAP, NP Fertilizer Production

This is the largest-volume application of industrial H3PO4 in Vietnam. H3PO4 reacts with ammonia (NH3) to form Diammonium Phosphate (DAP) or Monoammonium Phosphate (MAP) — the main source of phosphorus (P2O5) in compound NPK fertilizers. NPK blending plants also use H3PO4 directly as a readily available phosphorus source, accelerating the granulation process in tower or rotary drum production lines.

Food and Beverage pH Adjustment

Technical Grade H3PO4, filtered of heavy metal impurities, is used as an acidity regulator (INS 338) in carbonated soft drinks (cola), some energy drinks, and processed meat products. Due to its triprotic acid content, H3PO4 creates a distinctive “sharp” sour taste different from citric acid, while also having a mild antimicrobial effect that extends the shelf life of beverages.

Metal Surface Treatment

In electroplating and mechanical manufacturing, H3PO4 is used to phosphate steel surfaces before painting or plating — creating a zinc/iron phosphate coating that improves paint adhesion and rust resistance. H3PO4 is also used as a mild rust-removal solution (replacing HCl in stages requiring slower, more controlled corrosion) and for electropolishing stainless steel.

Water Treatment — Scale Prevention and pH Adjustment

H3PO4 is dosed in small amounts into water supply systems, boiler water, and cooling towers to form a protective phosphate film, limiting calcium carbonate (CaCO3) scale buildup on pipes and heat exchange surfaces. H3PO4 is also used to adjust water pH down to a neutral-to-mildly-acidic level in RO (reverse osmosis) systems to reduce mineral salt precipitation on the filter membrane.

Industrial Cleaning Agents

H3PO4 is a component in many specialized industrial cleaning formulas (limescale removers, mild rust removers, stainless steel cleaning solutions for the food industry — CIP) due to its ability to dissolve mineral scale without causing the strong corrosion of other inorganic acids at the same dilution concentration.

Case Study: Calculating H3PO4 Dosage for NPK/DAP Production

Anonymized context: An NPK fertilizer plant with a capacity of 60,000 tons of product per year in a Southern industrial zone posed the problem of calculating the amount of H3PO4 85% needed to ensure the P2O5 content in the NPK 16-16-8 formula.

Calculation basis (based on the chemical reaction and actual COA data of Loc Thien’s H3PO4 85%):

DAP-forming reaction: 2 NH3 + H3PO4 → (NH4)2HPO4

Molar mass: H3PO4 = 98 g/mol; P2O5 = 142 g/mol. Conversion ratio of equivalent P2O5 in 2 molecules of H3PO4: 142 ÷ (2 × 98) = 0.7245.

With H3PO4 85%, the equivalent P2O5 content in 1 ton of solution: 1,000 kg × 0.85 × 0.7245 ≈ 616 kg equivalent P2O5/ton of H3PO4 85%.

To achieve 16% P2O5 in 1 ton of NPK 16-16-8 product (equivalent to 160 kg P2O5/ton NPK, assuming all P2O5 comes from H3PO4 without blending in other phosphorus sources), the plant needs:

160 kg P2O5 ÷ 616 kg P2O5/ton H3PO4 85% ≈ 0.26 tons of H3PO4 85%/ton of NPK product.

With a capacity of 60,000 tons of NPK/year, the estimated H3PO4 85% demand is about 15,600 tons/year if all phosphorus comes from H3PO4 (in practice, plants typically blend in commercial DAP/MAP or apatite ore, so the amount of H3PO4 imported directly is lower than this figure, depending on the specific formulation).

Expert quote: “An H3PO4 content deviation of just 2-3% from the published COA is enough to throw off the P2O5 ratio in the NPK formula, causing the product to fail the specifications printed on the packaging. For fertilizer plants, we always recommend cross-checking the COA of each batch before adding it to the formulation, rather than relying solely on the parameters stated in the framework contract.” — Tran Minh Tuan, Head of Technical Department, Loc Thien Chemical

Case Study: H3PO4 for Metal Surface Treatment & Water Treatment

Metal surface treatment (pre-paint phosphating): A steel structure fabrication workshop in a Southern industrial zone uses H3PO4 solution diluted from H3PO4 85% (diluted to a working concentration of 3-5% per the technical instructions of the phosphating line) to treat steel surfaces before electrostatic painting. The resulting phosphate layer improves paint adhesion and extends rust protection compared to bare steel surfaces treated only with standard degreasing.

Water supply/boiler water treatment: H3PO4 85% is diluted into a low-concentration metering solution (per the recommendations of the water treatment system operator, based on incoming hardness and actual flow rate) to limit CaCO3 scale buildup on heat exchange piping. This application requires jar-testing or actual trials at the specific system — a fixed dosage cannot be applied to every plant because incoming water hardness, flow rate, and equipment configuration vary significantly between facilities.

For both applications, Loc Thien recommends customers request an H3PO4 85% sample (with a sample COA) to run field trials before committing to a large order — especially for water treatment systems where input parameters vary seasonally.

Safety & Storage of H3PO4

H3PO4 85% is a corrosive acid (GHS classification: Skin Corr. 1B, H314 — causes severe skin burns and eye damage). Although it does not fume heavily or corrode metal as quickly as concentrated HCl or H2SO4, H3PO4 can still cause chemical burns upon direct contact with skin, eyes, or if acid mist is inhaled during decanting in enclosed areas.

Mandatory PPE when handling H3PO4 85%:

• Chemical-resistant gloves (nitrile rubber or PVC, thickness ≥0.5mm)
• Sealed safety goggles or full face shield
• Acid-resistant protective clothing, rubber boots in the decanting area
• Dust/gas mask if operating in enclosed or poorly ventilated spaces

Compatible tank and equipment materials:

• Recommended: FRP (fiberglass-reinforced plastic), HDPE, 316L stainless steel for systems with prolonged contact
• Avoid: ordinary carbon steel (slow but continuous corrosion), aluminum at high concentrations

Storage principles: Keep in a dry, cool place, away from direct sunlight and heat sources. Absolutely avoid strong oxidizers (such as potassium permanganate, chlorates) and strong alkalis (concentrated NaOH, KOH) — neutralization or oxidation reactions can generate significant heat, potentially cracking storage tanks or splashing chemicals. The storage area should have an emergency eyewash station and full-body shower within 10 seconds’ walking distance.

Spill response: Isolate the area, use inert absorbent materials (sand, soil, specialized acid absorbents) to contain the spill, and do not use flammable organic materials. Neutralize with lime powder or dilute Na2CO3 before rinsing with water, following chemical emergency response procedures and the MSDS accompanying the shipment.

Packaging & Transportation Specifications

H3PO4 85% from Loc Thien is packaged in standard 35kg plastic drums, suitable for small and medium-sized plants, easy to store, and not requiring upfront investment in dedicated storage tanks.

For large orders (NPK plants, large-scale water treatment units with recurring needs), Loc Thien can package as requested and deliver via dedicated 5–30 ton tanker trucks for customers who already have acid-resistant FRP/HDPE storage tank infrastructure at their plant — reducing packaging costs and decanting labor compared to individual drums. For smaller orders or customers without storage tanks, the plastic drum/truck option is usually still a more flexible and safer choice.

Loc Thien does not publish a fixed shipping rate per km, because logistics costs depend on the actual distance from the warehouse to the delivery point, packaging type (drums or tanker), and total order volume — each order receives a specific shipping quote upon contact.

Criteria for Choosing an H3PO4 Supplier

When evaluating an H3PO4 supplier for your plant, check the following criteria:

1. Batch COA — Require a COA that accurately shows the H3PO4 content (85%), density, purity, and heavy metal impurity limits, which is especially important for food and water treatment applications.
2. Clear origin — H3PO4 imported from China or produced/processed in Vietnam has different impurity levels. Request specific origin information on the COA/contract.
3. Flexible packaging options — Can the supplier provide both 35kg plastic drums for small orders and 5–30 ton tankers for large orders? The ability to package to the plant’s specific requirements (smaller containers, labeling) is also a plus.
4. Complete documentation — Vietnamese-language MSDS, batch COA, VAT invoice. For food applications, additional confirmation of appropriate Technical Grade or food-grade certification is needed if requested by the customer.
5. Delivery time & warehousing — Does the supplier have a warehouse near your industrial zone? What is the actual delivery time for urgent orders?
6. Technical support — Can the supplier advise on dilution ratios and reference dosages for specific applications (fertilizer, water treatment, surface treatment), or do they only sell products with no consultation?

Requesting an H3PO4 85% sample with a sample COA before placing a large order is a step that tests a supplier’s technical capability and transparency — this is the criterion that most clearly reflects reliability before signing a long-term contract.

Where to Buy H3PO4 — How to Get a Quote?

Loc Thien supplies H3PO4 85% directly to fertilizer plants, metal surface treatment facilities, water treatment units, and some food applications nationwide. The product is packaged in 35kg plastic drums or as requested, sourced from China/Vietnam, Technical Grade standard, with COA and MSDS per batch. See full technical specifications and place an order on the product page: Phosphoric Acid H3PO4 85% China — Loc Thien Chemical.

Advantages of buying H3PO4 at Loc Thien:

• Batch COA — verify actual content before receiving the shipment
• Packaged in 35kg plastic drums or custom packaging upon request
• Large orders can be delivered via 5–30 ton tankers for customers with FRP/HDPE storage tanks
• Vietnamese-language MSDS, full VAT invoice, provided upon request
• Direct supply, without multiple layers of intermediaries

How to get a fast H3PO4 quote: Call 0979 891 929 or send a request via email [email protected], providing 3 pieces of information: concentration (85%), quantity needed (drums or tons/month), and specific application (fertilizer, food, surface treatment, water treatment) to receive a quote and advice on the appropriate specification. For large recurring orders, Loc Thien also supports framework agreements and commits to batch COA before payment.

Related content: Learn more about other industrial acids supplied by Loc Thien: Buy Industrial HCl at a Good Price, Nationwide Delivery and Comparing HCl and H2SO4 — Which Acid to Choose for Each Industrial Application.

Frequently Asked Questions

Call 0979 891 929 — H3PO4 85% quote within 15 minutes, COA/MSDS per batch, nationwide delivery.

Loc Thien INVESTMENT AND DEVELOPMENT COMPANY LIMITED — Tax ID 0313650856 · 452/6B Tinh Lo 10 (Provincial Road 10), Binh Tri Dong Ward, Ho Chi Minh City · ☎ 0979 891 929 · hoachatlocthien.com

Industrial Field Operation & Batch Quality Verification

1. Incoming Batch COA Verification & Regulatory Compliance (Law on Chemicals 69/2025/QH15)

When operating industrial water treatment, surface finishing, or textile dyeing lines in Vietnam, engineering teams must verify every chemical delivery against its batch-specific Certificate of Analysis (COA) and 16-section GHS Safety Data Sheet (SDS). Under the Vietnam Law on Chemicals No. 69/2025/QH15, Decrees 24/2026/ND-CP, 25/2026/ND-CP, and 26/2026/ND-CP, and QCVN 40:2025/BTNMT on industrial wastewater discharge:

• Specific Gravity & Assay Verification: Upon arrival of a 5–30-ton tanker or IBC tote shipment, plant QA technicians measure specific gravity at 20 °C using a calibrated hydrometer and cross-check active concentration against the batch COA issued by Loc Thien Chemical and verified via Quatest 3 (ISO/IEC 17025).
• Impurity & Heavy Metal Control: Trace heavy metals (Fe, Pb, As, Hg, Cd, Cr⁶⁺) and insoluble matter are strictly controlled to prevent catalyst poisoning in Fenton reactors, membrane fouling in RO/UF systems, or shade deviations in reactive textile dyeing.
• ZDHC MRSL v3.1 Level 1 Portfolio Boundary: For export-oriented textile and footwear FDI factories, Loc Thien Chemical maintains official ZDHC MRSL v3.1 Conformance Level 1 documentation for exactly 9 core products: four products certified by TUV SUD Product Service GmbH (NaOH, H2O2, Na2SO4, Na2CO3) and five products verified via Conformance Summary Report (CSR) and Analytical Test Report by TUV Rheinland Vietnam (H2SO4, FeCl2, HCl, Javel/NaOCl, PAC 31%).

2. Dosing Optimization, Storage Materials & Preventive Maintenance

1. Compatible Wetted Materials: Use cross-linked high-density polyethylene (XLPE / HDPE), polypropylene (PP-H), fiberglass-reinforced plastic (FRP with vinyl ester resin), or PTFE/PVDF-lined piping depending on corrosive and thermal conditions. Avoid unlined carbon steel or incompatible elastomers.
2. Automated Dosing Control: Integrate diaphragm metering pumps with real-time pH, ORP (mV), turbidity, or conductivity sensors. Always perform a 5-beaker Jar Test whenever raw water COD, TSS, or alkalinity shifts by more than 15%.
3. Secondary Containment & PPE: Storage tanks must sit inside an acid/alkali-resistant bund wall holding at least 110% of the largest tank volume. Operators handling unloading hoses must wear splash-proof chemical goggles, acid/alkali-resistant nitrile or neoprene gloves, face shields, and emergency respirators.

3. Multi-Role B2B Value Matrix (Procurement · QA/EHS Engineer · Plant Director)

• For Procurement Managers: Loc Thien Chemical is the direct manufacturer of FeCl2 30% solution and FeCl3 38–40% wastewater grade (3,000+ tons/month capacity), and a Tier-1 bulk commercial supplier of NaOH, HCl, H2SO4, PAC, NaOCl, H2O2, FeSO4, and Na2SiO3. Pricing is transparently structured around 5 technical cost drivers (active assay, packaging format, delivery distance from our 6 warehouses, order volume, and scheduled contract cadence) with a 15-minute technical quotation SLA.
• For Environmental & Process Engineers: Full technical support for Jar Test optimization, stoichiometry calculation, sludge minimization, and QCVN 40:2025/BTNMT compliance auditing.
• For FDI Plant Directors: Guaranteed supply continuity via 6 regional warehouses (Ba Ria - Vung Tau, Dong Nai, Binh Duong, Da Nang, Can Tho, Bac Ninh) and a dedicated 5–30-ton tanker fleet (4 hours in inner HCMC, 24–48 hours across Southern & Mekong Industrial Parks, 2–3 days in Northern & Central Vietnam).

4. Related Technical Resources & 15-Minute Quotation Gateway

• Explore our full industrial catalog: Industrial Chemical Catalog | Technical Knowledge Hub | Request a 15-Minute Technical Quote
• Legal Head Office: 452/6B Tinh Lo 10, Binh Tri Dong Ward, Binh Tan District, Ho Chi Minh City, Vietnam (Head Office only — all physical stock is dispatched from our 6 regional industrial park warehouses).
• 24/7 Technical Hotline: 0979 891 929 (Please contact hotline 0979 891 929 for detailed delivery procedures) | Official Email: [email protected]

In-Depth Engineering Guides in This Chemical Cluster

• Phosphoric Acid H3PO4 85% in Steel Derusting, Pre-Paint Zinc/Iron Phosphating & Biological Wastewater Nutrient Dosing (BOD:N:P)
• Nitric Acid HNO3 68% in Stainless Steel Pickling, ASTM A380 / ASTM A967 Passivation & Electroplating Pretreatment