Phosphorous Acid Supplier in China
Source high-assay phosphorous acid for phosphite chemistry, chemical synthesis, reducing applications and industrial formulations, supported by specification control and export logistics.
- CAS 13598-36-2
- H₃PO₃
- Typical commercial assay ≥98.5%
Phosphorous Acid for Industrial Buyers
Phosphorous acid is H₃PO₃, a phosphorus oxoacid with a molecular weight of about 81.99 g/mol. It must not be confused with phosphoric acid, H₃PO₄. The lower phosphorus oxidation state gives phosphorous acid different reaction behavior and makes it valuable as an intermediate in phosphite chemistry.
The previous version of this page incorrectly described phosphoric acid; this specification has been corrected. Buyers should evaluate assay, chloride, phosphate, sulfate, iron and heavy metals against the intended reaction or formulation.
For an accurate offer, specify the intended application, target assay, critical impurity limits, shipment quantity, destination and preferred delivery term.
Key Product Specifications
Reference values describe the product category. The agreed specification and batch COA govern each shipment.
| Product name | Phosphorous Acid |
|---|---|
| CAS number | 13598-36-2 |
| Molecular formula | H₃PO₃ |
| Molecular weight | 81.99 g/mol |
| Available assay | Typical commercial assay ≥98.5% |
| Grade | Industrial grade |
| Typical appearance | White crystalline, hygroscopic solid |
Common Phosphorous Acid Applications
Final suitability depends on formulation, process conditions, grade and local regulatory requirements.
Phosphite intermediates
A key raw material for manufacturing phosphites and other phosphorus-containing intermediates.
Reducing chemistry
Used where the +3 phosphorus oxidation state provides required reducing behavior in a validated process.
Stabilizer production
An input for selected stabilizer, antioxidant and specialty formulation manufacturing routes.
Water-treatment chemistry
Used as an intermediate in producing certain phosphonate and scale-control chemistries.
Agricultural formulations
Associated with phosphite-related products; only approved finished formulations should be used according to local labels.
Specialty chemical synthesis
Selected for process routes that require controlled phosphate, chloride, sulfate or metal impurities.
Built for International Chemical Supply
Moisture-resistant 25 kg, 50 kg and bulk-bag configurations may be available. Exact package, inner liner, net weight and palletization must be confirmed for the order.
Confirm specification
Agree grade, assay, impurity limits, quantity and destination.
Approve packing and documents
Confirm container, labels, palletization, COA, SDS and shipping requirements.
Production and quality release
Traceable batch testing supports release against the agreed specification.
Loading and shipment
Coordinate container loading, export documents and delivery to the agreed port.
Phosphorous Acid FAQ
Practical answers for sourcing, qualification, handling and export planning.
Is phosphorous acid the same as phosphoric acid?
No. Phosphorous acid is H₃PO₃, while phosphoric acid is H₃PO₄. They have different oxidation states, salts and reaction behavior.
What purity is available?
Typical commercial material is supplied at high assay, commonly around or above 98.5%. Confirm the exact specification and batch limits in the quotation and COA.
Which impurities should buyers review?
Commonly reviewed parameters include chloride, phosphate, sulfate, iron and heavy metals, but the critical limits depend on the process.
Can phosphorous acid be applied directly to crops?
Industrial raw material is not a ready-to-use agricultural product. Only properly formulated and authorized products should be used according to local labels and qualified advice.
How can I request documents and pricing?
Send the required assay, impurity limits, packaging, quantity and destination through the contact page.
Related Industrial Acids
Compare the other Hot products or visit the Hiacid technical blog for purchasing and handling guides.
Request Phosphorous Acid Specifications and Pricing
Tell us the grade, quantity, packaging, destination port and required delivery schedule. We will respond with current availability and commercial terms.