Sodium Dihydrogen Phosphate Dihydrate BP EP USP Pharma Grade: Chemical Profile and Industry Insights

What is Sodium Dihydrogen Phosphate Dihydrate?

Sodium Dihydrogen Phosphate Dihydrate, recognized in the chemical trade as NaH₂PO₄·2H₂O, belongs to a group of sodium phosphates. This compound shows up in many pharmaceutical folders as a reliable buffering agent and pH regulator. The pharma grade, adhering to BP, EP, and USP benchmarks, reaches a purity level high enough for use in drugs, food, and biotechnology. Understanding this material’s specifications isn't just for regulatory comfort; it directly ties into drug safety, product stability, and consistent manufacturing. HS Code 283522 serves as the global identifier, supporting transparent trade and compliance checks.

Chemical Structure and Properties

Each molecule of sodium dihydrogen phosphate dihydrate consists of a sodium ion, a dihydrogen phosphate anion, and two water molecules of hydration. The molecular formula reads NaH₂PO₄·2H₂O, while the molar mass clocks in at about 156.01 g/mol. The material appears as colorless, transparent crystals, or as white powder, depending on moisture and handling conditions. On the shelf, a jar may reveal delicate flakes, a flowable granular powder, or small, crystalline pearls. Water dissolves these crystals with ease, resulting in a clear, mildly acidic solution. Its density hovers around 1.91 g/cm³ for the solid, shifting lower in solution form.

Physical Specifications and Forms

Sodium dihydrogen phosphate dihydrate picks up different forms, from fine powder to bulky flakes or compact pearls. Bulk density ranges from 800 to 900 kg/m³ as a solid, though granular size impacts this number. It melts at about 60°C, beyond which it sheds water and yields the anhydrous salt. As a raw material, the physical form shapes its usability. Pharmacies and labs measure out grams from crystalline stock for solutions. On industrial scales, tanker trucks transport liquid solutions by the liter, each batch blended, tested, and tagged for concentration. Flakes flow easily into mixing vats when producing pharmaceutical injectables. Tablets call for consistent, dry powder to assure even content in every pill.

Molecular and Solution Properties

In labs and manufacturing, sodium dihydrogen phosphate dihydrate plays a crucial role due to its strong solubility in water and precise pH adjusting properties. It forms phosphate buffers with disodium phosphate, stabilizing biological products, extending shelf lives, and providing optimal reaction environments. Each gram delivers predictable molar strength—0.0064 mol of NaH₂PO₄·2H₂O per gram. Its pH in a 1% solution lands between 4.2 and 4.5, furnishing a mild acidity ideal for pharmaceutical processes. Solutions carry no color, no strong odor, and leave no sediment.

Industrial and Pharmaceutical Applications

This material carves out its place in industries that demand high purity, such as pharma, food, and lab research. In my own work handling buffer formulations for protein purification and injectable drug manufacture, no other salt matches the reliability of sodium dihydrogen phosphate dihydrate for fine-tuning pH. Drug companies rely on it for isotonic injections, oral solutions, and as a critical component in dialysis products. Food producers add it to adjust acidity, while water treatment operators count on it as a phosphate source in corrosion control. Its raw material grade ensures trace contaminants—lead, arsenic, iron—stay far below alarming limits. Each batch goes through rigorous analysis, with impurity profiles checked against BP, EP, and USP standards.

Material Handling, Storage, and Safety

Sodium dihydrogen phosphate dihydrate rests safely in most storage rooms under dry, cool conditions. Bags and barrels resist most corrosion, although excessive humidity or water exposure will clump the powder and generate heat as the salt dissolves. Direct contact doesn’t burn, but dusty clouds can irritate the eyes and airways. Putting on gloves and goggles is common sense in both lab and industrial settings. No explosive hazards exist, and fires rarely involve this salt—though it decomposes above 200°C, giving off irritating fumes. I’ve seen manufacturing floors rely on dust extraction systems and strict labeling practices to keep cross-contamination and accidental dosing at bay. Spills sweep up easily with dry methods, and water washes residue away without lasting harm.

Safe Use and Hazard Awareness

While sodium dihydrogen phosphate dihydrate doesn’t rank high on hazard scales, regulators and users still flag it as an irritant for certain workers with long-term contact. Food and pharma applications demand strict allergen controls and batch tracking. Material Safety Data Sheets (MSDS) call out its low acute toxicity but urge fast cleanup to prevent slips and inhalation. No evidence links this salt with environmental harm or bioaccumulation. Yet, it remains a phosphorus source—uncontrolled use in water treatment can still feed algal blooms downstream. Solutions to hazards revolve around local exhaust ventilation, well-sealed containers, and robust hygiene after handling. Waste disposal follows municipal chemical guidelines; phosphate-rich runoff never enters surface water untreated.

Quality Control, Authenticity, and Compliance

Every reputable raw materials supplier offers analysis certificates for sodium dihydrogen phosphate dihydrate. Purity, pH range, moisture, solubility, and appearance show up on each lot document. Regulators check the batch for international HS Code compliance during shipping and customs processing. Phosphate levels get scrutinized, especially in pharmaceutical grades where impurities carry enormous risk. Authentication solutions today include batch-level barcoding and real-time tracking in supply chains, which both keep fraud at bay and ensure traceability. In my experience, robust supplier audits and sample testing catch quality slips before they hit the production line.

Potential Solutions and Improvements

Challenges with sodium dihydrogen phosphate dihydrate center on handling, environmental phosphorus management, and quality assurance. Manufacturers work to develop more accurate moisture barrier packaging and anti-caking agents to keep powders free-flowing through long supply chains. Waste phosphate problems push facility investment into closed-loop water treatment, with spent process water cleaned and reused. Quality assurance teams move towards regular third-party audits and real-time analytics to flag impurity spikes and shipment discrepancies. In labs, automation reduces human error in weighing, labeling, and dispensing, which both minimizes exposure and smooths out production hiccups.

Summary Properties Table

Chemical Name: Sodium Dihydrogen Phosphate Dihydrate
Molecular Formula: NaH₂PO₄·2H₂O
Molar Mass: 156.01 g/mol
HS Code: 283522
Appearance: Colorless crystal, white powder, flakes, or pearls
Density: 1.91 g/cm³ (solid)
Solubility: Easily dissolves in water
pH (1% solution): 4.2–4.5
Melting Point: 60°C (dehydrates and decomposes at higher temperature)
Common Forms: Flakes, powder, pearls, liquid solutions, crystals
Hazards: Irritant, no serious acute risks under standard handling
Applications: Pharmaceuticals, food processing, water treatment, laboratory analysis
Compliance: BP, EP, USP standards, MSDS, batch-level analysis