Phosphorous Acid
Crystalline Phosphorous Acid (phosphonic acid, CAS 10294-56-1), min. 99.0%, supplied wholesale by Zyntex. Raw material for phosphite fertilizers, HEDP and ATMP phosphonates and plastic stabilizers. CoA and SDS with every lot.
Description
Phosphorous Acid Product Overview
Phosphorous acid (H3PO3, also listed under CAS 13598-36-2) is a white, crystalline, very hygroscopic solid that melts at about 73°C and dissolves easily in water. Unlike Phosphoric acid, it has only two acidic hydrogen atoms and acts as a reducing agent.
Agrochemical producers neutralize it with potassium or other bases to make phosphite salts such as Monopotassium phosphite, used in foliar fertilizers, biostimulants and plant protection products. Water treatment chemical producers use it to make phosphonates such as HEDP (with Acetic acid derivatives) and ATMP, which prevent scale and corrosion.
It is also a raw material for phosphite stabilizers and antioxidants for plastics, and it serves as a reducing agent in chemical synthesis. Because it is strongly hygroscopic, it must be kept in tightly closed packaging.
Key Applications of Phosphorous Acid
Main application areas:
🌱 Agrochemicals
Raw material for potassium and other phosphite salts.
💧 Water Treatment
Raw material for HEDP and ATMP phosphonate scale inhibitors.
🏭 Plastic Additives
Raw material for phosphite stabilizers and antioxidants.
🧪 Chemical Synthesis
Reducing agent and phosphorus source.
Phosphorous Acid Technical Specifications
| Parameter | Standard Value |
|---|---|
| Product Name | Phosphorous acid |
| CAS Number | 10294-56-1 (also 13598-36-2) |
| Molecular Formula / Weight | H3PO3 / 82.00 g/mol |
| Assay / Purity | Min 99.0% |
| Appearance | White crystalline solid |
| Melting Point | approx. 73°C |
| Documents | CoA and SDS with every lot |
⚠️ Safety & Handling: Harmful if swallowed and causes severe skin burns and eye damage. Wear acid-resistant gloves, goggles and protective clothing. Store in tightly closed containers in a cool, dry place, away from bases and oxidizers; on strong heating it can release toxic phosphine gas. Always consult the Safety Data Sheet (SDS) for full classification and handling instructions.
Frequently Asked Questions
What is the difference between phosphorous acid and phosphoric acid?
Phosphorous acid (H3PO3) is a reducing acid used for phosphites and phosphonates. Phosphoric acid (H3PO4) is fully oxidized and used in food, phosphates and metal treatment.
Why does it clump during storage?
It is very hygroscopic and absorbs moisture from the air. Keep containers tightly closed and store in a dry place.
How can I get a price and documents?
Prices depend on quantity, packaging and destination. Contact us with your required volume to receive a quotation together with the CoA and SDS.
