CAS No. 13598-36-2
13598-36-2
H3o3p
237-066-7
Phosphorous Acid
Crystal
Agriculture Grade
Strong Acid
Inorganic Acid
Tech Grade
Paper Bag
Polyatomic Acid
Oxidizing Acid
Volatile Acid
Stabilized Acid
Chenghexin
Customized
Phosphorous Acid
China
2811199090
Product Description
Phosphorous acid is an intermediate in the preparation of other phosphorous compounds. It is a raw material to prepare phosphonates for water treatment such as iron and manganese control, scale inhibition and removal, corrosion control and chlorine stabilization. The alkali metal salts (phosphites) of phosphorous acid are being widely marketed either as an agricultural fungicide (e.g. Downy Mildew) or as a superior source of plant phosphorous nutrition. Phosphorous acid is used in stabilizing mixtures for plastic materials. Phosphorous acid is used for inhibiting high-temperature of corrosion-prone metal surfaces and to produce lubricants and lubricant additives. Phosphorous acid is as an intermediate in the preparation of other phosphorous compounds. Because preparation and uses of "phosphorous acid" actually pertain more to the major tautomer, phosphonic acid, it is more often referred to as "phosphorous acid". Phosphorous acid has the chemical formula H3PO3, which is best expressed as HPO(OH)2 to show its diprotic character. It has been shown to be a stable tautomer.

Phosphorous acid Chemical Properties |
Melting point | 73 °C |
Boiling point | 200 °C |
density | 1.651 g/mL at 25 °C(lit.) |
vapor pressure | 0.001Pa at 20ºC |
Fp | 200°C |
storage temp. | 0-6°C |
solubility | DMSO (Slightly), Methanol (Slightly), Water (Sparingly) |
form | Crystals |
pka | pK1 1.29; pK2 6.74(at 25ºC) |
Specific Gravity | 1.651 |
color | White |
Water Solubility | SOLUBLE |
Sensitive | Air Sensitive & Hygroscopic |
Merck | 14,7346 |
Stability: | Stable. Incompatible with strong bases. Hygroscopic. |
CAS DataBase Reference | 13598-36-2(CAS DataBase Reference) |
NIST Chemistry Reference | (HO)2HPO(13598-36-2) |
EPA Substance Registry System | Phosphonic acid (13598-36-2) |
Safety Information |
Hazard Codes | C |
Risk Statements | 22-35 |
Safety Statements | 26-36/37/39-45 |
RIDADR | UN 2834 8/PG 3 |
WGK Germany | 1 |
RTECS | SZ6400000 |
F | 3 |
TSCA | Yes |
HazardClass | 8 |
PackingGroup | III |
HS Code | 28092019 |
Phosphorous acid is used to produce the fertilizer phosphate salt like potassium phosphite, ammonium phosphite and calcium phosphite. It is actively involved in the preparation of phosphites like aminotris(methylenephosphonic acid) (ATMP), 1-hydroxyethane 1,1-diphosphonic acid (HEDP) and 2-phosphonobutane-1,2,4-tricarboxylic Acid (PBTC), which find application in water treatment as a scale or corrosive inhibitor. It is also used in chemical reactions as a reducing agent. Its salt, lead phosphite is used as PVC stabilizer. It is also used as a precursor in the preparation of phosphine and as an intermediate in the preparation of other phosphorus compounds.
Product Quality Advantages
Vast Production Capacity With an annual production capacity of 5,000 tons, we guarantee a long-term and stable supply to meet your needs.
Innovative Separation Technology Our research and development team, consisting of 28 highly skilled professionals, pioneers in separation technology, ensures our leading edge in product innovation and development.
Unmatched Product Purity for Phosphorous Acid
Our Phosphorous Acid redefines excellence in product purity, reaching an unmatched purity level beyond 98%, thereby establishing a revolutionary industry standard for outstanding quality. This extraordinary level of purity emphasizes our dedication to offering products that surpass the most rigorous specifications and exceed performance expectations.
Innovative Separation Technology Our research and development team, consisting of 28 highly skilled professionals, pioneers in separation technology, ensures our leading edge in product innovation and development.
Unmatched Product Purity for Phosphorous Acid
Our Phosphorous Acid redefines excellence in product purity, reaching an unmatched purity level beyond 98%, thereby establishing a revolutionary industry standard for outstanding quality. This extraordinary level of purity emphasizes our dedication to offering products that surpass the most rigorous specifications and exceed performance expectations.

1. Can I get samples?
Yes, free samples are available.
Samples will usually be sent out within 1-3 working days.
2. Do you accept customized orders?
Yes, both product and package can be customized.
3. What is the payment terms?
TT, LC, DP are available.
Please note that OME orders require payment prior to shipment.
4. What is the lead time for mass production?
Delivery time depends on product type and quantity.
Our company has a digital ordering system to ensure scientific and reasonable scheduling of orders, please consult the sales staff you contacted.
5. How to guarantee the product quality?
We have a complete raw material inspection, quality control and pre-factory inspection system to ensure that the order delivered to you is in line with the contract.
In addition, it also supports third-party inspection before shipment. If the inspection fails, the customer's payment will be refunded, and the loss caused by the breach of contract will be compensated.
6. How to check the order status after payment?
After the order is confirmed, the merchandiser will follow up every week and update the order status to you by email.
7. How to deal with after-sales problems?
The after-sales service implements the order responsibility system, and the salesman is the first responsible person for the order. The after-sales service department will set up a service team after receiving the complaint. They will complete the incident investigation and provide you with a resolution within 72 hours.
Why Choose Us: Enhanced Value and Unwavering Support
With over 22 years as a chemicals supplier, we offer unparalleled experience, continuous service, and a commitment to quality and innovation that sets us apart. Our dedication to solving problems and supporting our clients' success makes us the ideal partner in your chemical supply chain.
Stable and Preferential Factory Prices
Our competitive pricing model is designed to offer you significant savings. By maintaining stable and preferential factory prices, we ensure that your procurement costs are minimized, allowing you to allocate resources more effectively across your operations.
Reliability in Supply
We understand the critical importance of reliability in your production and business development plans. Our robust supply chain infrastructure guarantees a consistent and uninterrupted supply of chemicals, ensuring that your operations proceed without delay or disruption.
Unmatched After-Sales Support
Our dedication to the chemical industry is not just a business stance but a lifelong commitment. Aspiring to be the highest quality service provider, we offer comprehensive after-sales support tailored to the unique needs of our customers. Our team is not just knowledgeable about our products but deeply understands the broader industry context, enabling us to provide solutions and support that truly make a difference.
Choosing us means partnering with a provider that prioritizes your cost-efficiency, supports your growth with a reliable supply chain, and stands by you with unparalleled after-sales service. We are more than just a supplier; we are your trusted partner in navigating the complexities of the chemical industry.
Sincere Chemical Co., Ltd., established in 2021, is located in the Huarun Mansion, Longhua District, Haikou City, Hainan Province, boasting a brand-new, ultra 5A-level office environment. Based on the profound corporate culture of Shijiazhuang Chenghexin Chemical, which has more than 20 years of experience, the company fully supports the development of import and export-related businesses for its Hainan branch. The company has a harmonious atmosphere, generous benefits, and offers substantial room for growth.
Since its inception, the company has always adhered to the development philosophy of "integrity, stability, innovation, and precision". It continuously explores and innovates, enhancing the R&D and production capabilities of new products. The company's products are constantly optimized and perfected, and it maintains long-term stable cooperation with domestically powerful factories as well as national and provincial scientific research institutes. This ensures that the products' technology is advanced, quality is stable, and prices are competitive, now forming a professional chemical raw material supply enterprise that combines science, industry, and trade with both domestic and international trade.
In recent years, the company has won several national and provincial awards and titles for being a trustworthy enterprise and has been recognized as a quality and efficiency-oriented enterprise. It has also received accolades and recommendations from internet companies like Baidu, and HC.com; particularly, it has been featured in a special interview and promotion by the CCTV Securities Information Channel's "Brand Power" program.
After more than 20 years of efforts, the company has continued to grow and expand. Its client base includes highly influential local enterprises, listed companies, and Fortune 500 companies, earning long-term trust and support from both new and old customers. With a bright future ahead, all employees are confident in the company's development.
Since its inception, the company has always adhered to the development philosophy of "integrity, stability, innovation, and precision". It continuously explores and innovates, enhancing the R&D and production capabilities of new products. The company's products are constantly optimized and perfected, and it maintains long-term stable cooperation with domestically powerful factories as well as national and provincial scientific research institutes. This ensures that the products' technology is advanced, quality is stable, and prices are competitive, now forming a professional chemical raw material supply enterprise that combines science, industry, and trade with both domestic and international trade.
In recent years, the company has won several national and provincial awards and titles for being a trustworthy enterprise and has been recognized as a quality and efficiency-oriented enterprise. It has also received accolades and recommendations from internet companies like Baidu, and HC.com; particularly, it has been featured in a special interview and promotion by the CCTV Securities Information Channel's "Brand Power" program.
After more than 20 years of efforts, the company has continued to grow and expand. Its client base includes highly influential local enterprises, listed companies, and Fortune 500 companies, earning long-term trust and support from both new and old customers. With a bright future ahead, all employees are confident in the company's development.
