Molekula
Phosphorous acid
Supplying 4,500+ customers in over 80 countries
ISO 9001:2015 & ISO 14001:2015 certified · Supplying laboratories and industry since 2000 · Listed pack sizes are a starting point — we manufacture, source and repack to the quantity you need
Phosphorous acid is a reducing agent and intermediate used in agriculture, water treatment, and chemical synthesis. It is a colorless, crystalline solid with the molecular formula H3O3P and a molecular weight of 82.00 g/mol. It is stable at ambient temperatures and should be handled with care due to its hazardous nature. CAS number: 13598-36-2. Molekula supplies Phosphorous acid from research to bulk quantities with full documentation and ISO 9001:2015 traceability.
Example image for illustration only. Other packaging and pack sizes are available.
Pricing & pack sizes
These pack sizes aren't a limit. Molekula manufactures, sources and repacks to order — if you need 500 kg and only see 1 kg listed, . We quote from grams to multi-tonne.
Need a different size? Add the nearest pack and change the size in your basket — we price it at the same rate per unit.
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500 g — £35.80 per pack ex VAT · £42.96 inc. VAT
Need a different quantity or pack?
Tell us how much you need and when — drums, IBCs, sacks or a one-off bulk lot. We'll manufacture or source it and come back with a price.
Prices exclude VAT/sales tax and shipping.
Specifications
| Property | Value |
|---|---|
| Appearance | White to off-white powder or crystal |
| Chloride (Cl-) | ≤0.02% |
| Assay | ≥98.0% |
| Iron (Fe) | ≤ 0.5% |
| Sulphates (SO4)(2-) | ≤0.01% |
| Phosphate (PO4)3- | ≤0.6% |
Storage & handling
| Property | Value |
|---|---|
| Storage Temperature | Ambient |
| Transport Class | 8 |
| Packing Group | III |
| Acidity | Acid |
Identification
| Property | Value |
|---|---|
| SKU | 14596568 |
| CAS Number | 13598-36-2 |
| IUPAC Name | phosphonic acid |
| Molecular Formula | H3O3P |
| Molecular Weight | 82.00 |
| Exact Mass | 81.982 |
| SMILES | OP(=O)O |
| InChIKey | ABLZXFCXXLZCGV-UHFFFAOYSA-N |
| InChI | InChI=1S/H3O3P/c1-4(2)3/h4H,(H2,1,2,3) |
| PubChem CID | 407 |
| UN Number | UN2834 |
| REACH Code | Y110 |
| TSCA Listed | Yes |
| HTS Code | 28111961 |
| Tariff Code | 2811198090 |
Safety & GHS
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Corrosive
GHS05
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Health Hazard
GHS07
Hazard statements
- H290 May be corrosive to metals
- H302 Harmful if swallowed
- H314 Causes severe skin burns and eye damage
Precautionary statements
- P260 Do not breathe dust/fume/gas/mist/vapours/spray
- P280 Wear protective gloves/protective clothing/eye protection/face protection
- P301+312 IF SWALLOWED: Call a POISON CENTER or doctor/physician if you feel unwell
- P301+330 IF SWALLOWED: Rinse mouth. Do NOT induce vomiting
- P303+361 IF ON SKIN (or hair): Remove immediately all contaminated clothing. Rinse with water/shower
- P305+351+338 IF IN EYES: Rinse with water for several minutes. Remove contact lenses if present and easy to do. Continue rinsing
Documents
Safety Data Sheets (SDS)
Available in English, English (US), French, German, Italian, Spanish.
Certificate of Analysis (CoA) by batch
Enter a lot or batch number to retrieve the CoA for that specific batch. We can generate one from spec data if no PDF is on file.
Synonyms
- Phosphonic acid
- Phosphorus trihydroxide
Frequently asked questions
What is phosphorous acid used for?
Phosphorous acid is used as a reducing agent, in the synthesis of pesticides, and as a corrosion inhibitor in industrial applications.
What is the chemical formula and molecular weight of phosphorous acid?
The formula is H3O3P and the molecular weight is 82.00 g/mol.
How should phosphorous acid be stored?
It should be stored at ambient temperature, away from moisture and incompatible materials.
What grade of phosphorous acid does Molekula supply?
Molekula supplies phosphorous acid in reagent grade.
Can Molekula supply phosphorous acid in bulk?
Yes, Molekula can supply phosphorous acid in bulk quantities upon request.
What documentation comes with a purchase of phosphorous acid?
Each order includes a Certificate of Analysis and Safety Data Sheet (SDS) with the shipment.
Ready to order or need a custom pack?
Tell us the product, grade, and quantity — Molekula usually responds within one working day with pricing and lead time.