Product Overview
Phosphoric Acid 75% ACS Grade is a clear, colorless viscous liquid supplied at 75% concentration by weight. A triprotic inorganic acid, it releases protons in three successive stages — giving operators precise, graduated control over pH across a wide buffering range. That characteristic makes it a workhorse acid in water treatment, metal cleaning, fertilizer manufacturing, and analytical laboratory work.
The ACS Grade designation on the label tells procurement and QC teams that this product meets the grade specification their SOPs or analytical methods call for. Alliance Chemical offers it in sizes from 1-quart bottles through 330-gallon totes, covering bench-scale lab work through continuous industrial dosing.
Why This Concentration
At 75%, this solution occupies a practical sweet spot for most phosphoric acid applications. It is concentrated enough for direct use in pH adjustment, descaling, and formulation — yet it pours and meters freely at normal warehouse and plant temperatures without the crystallization risk that higher-concentration forms carry in cooler environments.
For operators running dilute cleaning baths or rinse-stage pH correction, 75% dilutes readily with water to any target strength. For production teams blending fertilizer or running large-volume processes, this concentration delivers a high active-acid payload per drum or tote, keeping freight efficient. If your process spec or method calls for ACS Grade specifically, this product satisfies that procurement requirement without forcing you to source a specialty-catalog item at specialty pricing.
Chemical Profile
Phosphoric Acid 75% ACS Grade carries CAS number 7664-38-2, with molecular formula H3O4P and a molecular weight of 97.995 g/mol. In its 75% aqueous form, the liquid is clear, colorless, and noticeably viscous. It is odorless, fully miscible with water, and exhibits low vapor pressure under ambient conditions. The density of the 75% solution is approximately 1.575 at 25 °C — substantially heavier than water, which matters when sizing pumps, calculating vessel loads, and estimating freight weight per container.
Industrial Applications
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pH Adjustment — Water Treatment & Process Control. Phosphoric acid's three dissociation steps buffer at different pH ranges, giving plant operators more gradual, controllable pH reduction than monoprotic mineral acids. Water-treatment facilities use it to condition influent ahead of membrane systems, adjust cooling-tower chemistry, and stabilize boiler feedwater. In chemical manufacturing, it serves as a process acid wherever chloride or sulfate contamination from HCl or H2SO4 is unacceptable.
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Fertilizer Production. Phosphoric acid is the primary phosphorus feedstock in the manufacture of monoammonium phosphate (MAP), diammonium phosphate (DAP), and liquid fertilizer blends. The 75% concentration feeds directly into ammoniation reactors, and the ACS Grade designation may be specified for formulations where tighter incoming-material documentation is required.
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Metal Cleaning & Surface Preparation. Phosphoric acid converts iron oxide to iron phosphate without aggressively attacking the base metal underneath. Fabrication shops, automotive refinishers, and coating applicators use it for descaling, rust conversion, and pretreatment before paint or powder coat. It leaves a light phosphate layer that improves coating adhesion.
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Laboratory Reagent Use. Analytical and research laboratories use ACS Grade phosphoric acid as a mobile-phase modifier in HPLC, a buffer component in biological and biochemical assays, and a general-purpose acid where the method or SOP specifies ACS Grade on the purchase order.
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Industrial Cleaning Formulations. Phosphoric acid is a base ingredient in CIP (clean-in-place) acid cycles for stainless-steel process equipment, dairy and beverage lines, and semiconductor wet benches. It dissolves mineral scale and metal-oxide films while being less fuming and less corrosive to stainless alloys than hydrochloric acid at comparable concentrations.
Handling & Storage
This product carries a Danger signal word (per the product's GHS classification). Two hazard statements govern its handling:
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H314 — Causes severe skin burns and eye damage (per the product's GHS classification).
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H290 — May be corrosive to metals (per the product's GHS classification).
Wear chemical splash goggles, a face shield, acid-resistant gloves (nitrile or butyl rubber), and a protective apron or acid suit when handling. Work in a well-ventilated area or under local exhaust; although vapor pressure is low, mist generation during transfer can irritate airways.
Store in the original HDPE or glass container, tightly sealed, in a cool, dry, ventilated space. Keep away from strong bases (sodium hydroxide, potassium hydroxide), oxidizing agents, and reactive metals such as aluminum and zinc — phosphoric acid will corrode these and generate hydrogen gas. The solution is hygroscopic; reseal containers promptly after dispensing to prevent moisture uptake and concentration drift. Do not store near food, feed, or drinking-water supplies.
Hazmat & Shipping
Phosphoric Acid 75% is a DOT-regulated hazardous material. Every shipment from our Taylor, TX facility is classified, marked, labeled, and documented in accordance with federal hazmat transportation requirements.
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UN Number: UN1805 (per 49 CFR 172.101)
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Hazard Class: 8 — Corrosive (per 49 CFR 172.101)
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Packing Group: III (per 49 CFR 172.101)
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Proper Shipping Name: Phosphoric acid solution (per 49 CFR 172.101)
Class 8 / PG III designation reflects a corrosive material in its least severe packing tier. Packages are prepared with the appropriate corrosive diamond labels and shipping documentation before they leave our dock.
Documentation
A Safety Data Sheet (SDS) ships with every order, available in English, Spanish, French, and Japanese. A lot-specific Certificate of Analysis (COA) is available on request — contact us with your order number or lot number and we will send it promptly. A Technical Data Sheet (TDS) providing product specifications is also available for download or on request.
Why Buy from Alliance Chemical
This phosphoric acid is available to order in sixteen size and pack configurations — from a single quart for method development up to 330-gallon totes for production-scale dosing — with SDS documentation in four languages and lot-specific COA on request. Alliance Chemical has served over 50,000 customers since 1998, shipping hazmat freight daily from our warehouse at 204 S Edmond St, Taylor, Texas. Shipping and handling guidance for this product is reviewed by Andre Taki, DOT Hazmat Specialist.
