Molekula
Boron oxide
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
Boron oxide (B2O3) is a white, glassy solid used primarily in the manufacture of fiberglass, specialty glasses, and ceramics, as well as a flux in metallurgy and a raw material for boron compounds. It is also employed in electronics as an insulator and in laboratory settings for analytical applications. Boron oxide has a CAS number of 1303-86-2, a molecular weight of 69.62 g/mol, and is stored at ambient conditions. It carries a Danger signal word due to its reproductive toxicity (H360FD: may damage fertility; may damage the unborn child). Molekula supplies boron oxide 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
Pack sizes & pricing
Pricing on request — packs available from research to bulk quantities.
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 |
|---|---|
| Water | ≤0.60% |
| Fe2O3 | ≤0.005% |
| B2O3 | ≥98.8% |
| Sodium (Na) | ≤0.02% |
| 120 Mesh (pass rate) | ≥95% |
| Silicon Dioxide (SiO2) | ≤0.10% |
| Calcium Oxide (CaO) | ≤0.01% |
| Aluminium oxide (Al2O3) | ≤0.005% |
Storage & handling
| Property | Value |
|---|---|
| Storage Temperature | Ambient |
| Acidity | Neutral |
Literature values
Published physical properties of the substance, not batch specifications.
| Property | Value |
|---|---|
| Appearance | Colorless, glassy or hexagonal crystals, hygroscopic |
| Odour | Odorless |
| Melting Point | 450 °C |
| Boiling Point | 1500 °C (crystal) |
| Density | 2.46 (relative, water = 1) |
| Solubility (other solvents) | Slowly soluble in 30 parts cold water; slowly soluble in 5 parts boiling water; soluble in alcohol, glycerol |
| Vapour Pressure | 0 mmHg (approx) |
| Refractive Index | 1.61 |
Source: PubChem CID 11073337 (HSDB, ICSC, The National Institute for Occupational Safety and Health (NIOSH))
Identification
| Property | Value |
|---|---|
| SKU | 33805057 |
| CAS Number | 1303-86-2 |
| IUPAC Name | 2,4,5-trioxa-1,3-diborabicyclo[1.1.1]pentane |
| Molecular Formula | B2O3 |
| Molecular Weight | 61.833 |
| Exact Mass | 70.0034 |
| SMILES | B12OB(O1)O2 |
| InChIKey | RPPTVYMVSNHGRG-UHFFFAOYSA-N |
| InChI | InChI=1S/B2O3/c3-1-4-2(3)5-1 |
| PubChem CID | 11073337 |
| REACH Code | Y110 |
| TSCA Listed | Yes |
| HTS Code | 28100010 |
| Tariff Code | 2810001000 |
Safety & GHS
-
Serious Health Hazard
GHS08
Hazard statements
- H360FD May damage fertility. May damage the unborn child.
Precautionary statements
- P261 Avoid breathing dust/fume/gas/mist/vapours/spray
- P263 Avoid contact during pregnancy/while nursing
- P280 Wear protective gloves/protective clothing/eye protection/face protection
- P308+313 IF exposed or concerned: Get medical advice/attention
Documents
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
- Boric acid (HBO2), anhydride
- Boric anhydride
- Boric oxide
- Boric oxide (B2O3)
- Boron oxide (B2O3)
- Boron Oxydatum
- Boron sesquioxide
- Caswell No. 109B
- Diboron trioxide
- Fused boric acid
Frequently asked questions
What is boron oxide (B₂O₃) commonly used for?
Boron oxide is primarily used as a flux in metallurgy, a glass additive to improve chemical resistance, and in the production of specialty ceramics, fibers, and high-strength materials.
What is the molecular formula and molecular weight of boron oxide?
The molecular formula is B₂O₃, and the molecular weight is 69.62 g/mol.
How should boron oxide be stored?
Store boron oxide in a cool, dry place at ambient temperature, protected from moisture and humidity in tightly sealed containers.
What purity grades of boron oxide does Molekula supply?
Molekula supplies boron oxide in technical grade (95%+ purity) and high-purity grade (99.9%+ purity) for specialized applications.
Can Molekula supply boron oxide in bulk quantities?
Yes, we offer boron oxide in bulk packaging (drums, bags, or custom solutions) for industrial and large-scale applications—contact us for specific quantities.
What documentation is provided with a boron oxide order?
Each order includes a Certificate of Analysis (CoA), Safety Data Sheet (SDS), and batch-specific documentation for traceability and compliance.
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.