Phosphorous Acid CAS 10294-56-1 Full Export Specification
1. Basic Chemical Identification
- IUPAC Name: Phosphorous acid
- Aliases: Orthophosphorous acid, Hydrophosphorous acid,
- CAS No.: 10294-56-1
- EINECS: 233-663-1
- MDL No.: MFCD00011674
- Molecular Formula: \(\boldsymbol{H_3PO_3}\)
- Molecular Weight: 81.996
- SMILES: OP(O)O
- HS Code: 2811199090
- UN Number: UN 2834
- IMDG Hazard Class: Class 8 Corrosive Solid, Packing Group III
- Signal Word: Danger
- Regulatory Note: REACH SVHC candidate substance, corrosive inorganic acid, aquatic hazardous material, TSCA registered
2. Physical & Chemical Properties
- Appearance: White crystalline flake solid; aqueous solution is colorless transparent liquid, strong acidic pungent odor
- Melting Point: 73.6 ℃
- Boiling Point: Decomposes above 180 ℃, releases phosphine & phosphorus oxide toxic fumes
- Solid Density (21 ℃): 1.651 g/cm³
- pH (10% aqueous solution): 1.0–1.5 (strong acid)
- Solubility: Highly soluble in water, ethanol; slightly soluble in acetone; insoluble in benzene, toluene, aliphatic hydrocarbons
- Stability
- Hygroscopic, absorbs moisture from air to deliquesce; must be hermetically sealed under dry environment
- Dibasic weak acid, undergoes neutralization with alkalis to produce phosphite salts
- Reductive property: Easily oxidized to phosphoric acid by air, oxidants, hydrogen peroxide
- Incompatible with strong bases, oxidants, alkali metals, concentrated nitric acid
- Core GHS Hazards
- H302: Harmful if swallowed
- H314: Causes severe irreversible skin burns and permanent eye damage (strong corrosive acid)
- H335: Acid dust/mist irritates respiratory tract, induces bronchial edema
- H412: Harmful to aquatic life with long-lasting bioaccumulation risk
3. Standard COA Technical Specifications
Grade 1: Industrial Synthetic Grade (Main Bulk Export, ≥98.5%)
| Test Item | Standard Specification | Test Method |
| H₃PO₃ Assay (Titration) | ≥98.5 wt% | Acid-base titration |
| Phosphate impurity (H₃PO₄) | ≤0.30 wt% | Colorimetric |
| Sulfate (SO₄²⁻) | ≤0.01 wt% | Turbidimetry |
| Chloride (Cl⁻) | ≤0.005 wt% | Turbidimetry |
| Moisture Content | ≤0.40 wt% | Karl Fischer |
| Heavy Metal (Pb) | ≤10 ppm | AAS |
| Arsenic (As) | ≤5 ppm | Silver diethyldithiocarbamate |
| Water Insoluble Matter | ≤0.02 wt% | Gravimetry |
Grade 2: High-Purity Reagent / Plastic Stabilizer Grade ≥99.0%
| Test Item | Standard Specification |
| Phosphorous acid purity | ≥99.0 wt% |
| Phosphate | ≤0.10 wt% |
| Moisture | ≤0.15 wt% |
| Total heavy metals | ≤3 ppm |
| No foreign insoluble particles | Clear aqueous solution |
4. Main Industrial Applications
1. Phosphite Salt & Agrochemical Pesticide Raw Material (Largest Consumption)
Core feedstock for manufacturing sodium phosphite, potassium phosphite, manganese phosphite; these phosphites act as broad-spectrum fungicides for fruit trees, vegetables, cereals to control downy mildew, blight and powdery mildew.
2. Polymer Stabilizer & Antioxidant
- Polycarbonate, PVC, nylon 1010 heat stabilizer & anti-yellowing agent; inhibits thermal oxidation degradation during plastic extrusion/molding
- Antioxidant auxiliary for polyester fiber, prevents fiber discoloration under high-temperature dyeing
3. Water Treatment & Metal Surface Treatment
- Reducing cleaning agent for industrial circulating water; removes heavy metal ions, inhibits pipeline corrosion
- Metal surface passivation agent for steel, aluminum alloy, forms anti-rust phosphite film
4. Fine Organic Synthesis Intermediate
- Reductive catalyst for pharmaceutical, dye intermediate production
- Phosphonating agent for manufacturing organophosphorus chelating agents (EDTMP, HEDP) for wastewater heavy metal removal
5. Laboratory Analytical Reagent
Standard dibasic reducing acid for redox titration, phosphite coordination complex research
5. Export Packaging & Storage Transportation
Standard Packing Options
- Solid industrial grade: 25kg woven plastic bag with double PE moisture-proof inner liner
- Ton jumbo bag: 1000kg waterproof woven bag with thick PE liner for factory bulk feeding
- 50% aqueous liquid grade: 200L HDPE plastic drum, airtight screw cap
- Lab small packing: 100g / 500g sealed plastic bottle
All pallets fixed with anti-slip steel strapping, fully wrapped waterproof acid-resistant composite film; transit temperature ≤25 ℃, strictly kept dry to avoid deliquescence.
Mandatory Warehouse Storage Rules
- Cool, dry, ventilated Class8 corrosive solid warehouse, indoor relative humidity <65%
- All packages fully sealed to block air moisture absorption
- Strict segregate from strong alkalis, oxidants, metal ingots, food raw materials & edible goods
- Equipped with acid dust/mist alarm, negative-pressure exhaust ventilation, soda ash neutralization emergency pool
Ocean Transport Rules (IMDG UN2834)
Class8 Corrosive Solid PG III marine pollutant dangerous goods; mixed loading with alkaline cargo, metal products and food is completely prohibited; prevent rain soaking and package rupture; full set of corrosive dangerous goods export documents mandatory for global customs clearance.
6. GHS Full Hazard Statements & Mandatory PPE
Hazard Statements
- H302: Harmful if swallowed
- H314: Causes severe skin burns and eye damage
- H335: May cause respiratory irritation
- H412: Harmful to aquatic life with long lasting effects
Mandatory PPE
- Dust half-face respirator with P2 particulate + acid vapor dual filter cartridge; full-face positive-pressure SCBA for large-scale feeding & leakage cleaning
- Double protection: fully sealed acid-proof chemical safety goggles + full anti-dust splash flame retardant face shield
- Double-layer thick butyl rubber acid-resistant impermeable gloves (nitrile only for short contact)
- Dust-proof impermeable full-body anti-corrosive protective overalls + heavy chemical resistant rubber boots
- Local negative-pressure dust extraction hood for all weighing, sampling & feeding operations (open-air handling prohibited)
Spill & First Aid Emergency Treatment
- Spill disposal: Evacuate irrelevant personnel instantly, cut all open flame & static sparks; cover crystalline powder with dry inert sand to suppress dust floating; collect residues into airtight plastic hazardous waste barrels; neutralize residual waste slowly with solid soda ash; prohibit direct discharge to sewer/water body
- Skin contact: Remove contaminated clothes instantly, flush skin with massive soapy running water continuously ≥30 minutes; hospital burn treatment mandatory
- Eye contact: Irrigate eyes with steady clean running water non-stop for minimum 30 minutes, urgent ophthalmic rescue mandatory
- Inhalation: Move victim to fully fresh air instantly, supply high-concentration oxygen for throat burning, severe cough and dyspnea
- Ingestion: Do NOT induce vomiting; drink large volume milk/clean water to relieve corrosive toxicity, transport patient to toxic emergency center with SDS document
7. Foreign Trade Selling Advantages
- Two quality grades available: industrial agrochemical/plastic stabilizer bulk grade & high-purity lab reagent grade, controlled low phosphate impurities to avoid plastic yellowing and pesticide efficacy interference
- Double-layer moisture-proof sealed woven bag packaging, no deliquescence or agglomeration during long cross-ocean sea transit
- Complete Class8 corrosive dangerous goods full set export documents (COA, English SDS, UN packaging certificate, IMDG maritime declaration, certificate of origin, heavy metal impurity inspection report), fully compliant with IMDG international maritime rules
- Flexible supply: small lab bottles, 25kg woven bags, full FCL ton bag bulk shipments and 50% liquid drum supply
- Exclusive raw material for phosphite fungicide and polycarbonate stabilizer manufacturing, stable reductive acid performance, long-term stable supplier for global agrochemical, plastic additive and water treatment factories worldwide
8. Full Set Export Supporting Documents
- Batch Certificate of Analysis (COA)
- English SDS Safety Data Sheet (hygroscopic corrosive inorganic reducing acid special version)
- UN Dangerous Goods Packaging Qualification Certificate (UN2834)
- IMDG Maritime Dangerous Goods Declaration File (Class8 PG III)
- Certificate of Origin
- Phosphate & heavy metal impurity compliance test report
United States
Egypt
Poland
