Substance profile
Diboron trioxide
Diboron trioxide is colorless, brittle, vitreous, semitransparent lumps or hard, white crystals and is odorless.
01 · Identification
What Diboron trioxide is
Diboron trioxide is colorless, brittle, vitreous, semitransparent lumps or hard, white crystals and is odorless. It boils at 1500 °C, melts at 450 °C.
Under the GHS it carries the signal word Danger.
02 · GHS classification
Hazards and label elements
Harmonised classification under CLP Annex VI. This is the legally binding classification in the EU; other jurisdictions may differ.
| Code | Hazard statement |
|---|---|
| H360FD | May damage fertility. May damage the unborn child. |
03 · Physical and chemical properties
Diboron trioxide properties
Every value is shown with the conditions it was measured under and the source it came from. Where sources disagree, all values are listed rather than one being picked — the difference is usually a different form of the substance, not an error.
| Property | Value | Conditions | Source |
|---|---|---|---|
| Boiling point | 1500 °C (2732 °F) | crystal | HSDB |
| 1860 °C (3380 °F) | NIOSH | ||
| 1860 °C (3380 °F) | at 760 mmHg | CAMEO | |
| Melting point | 450 °C (842 °F) | crystal | HSDB |
| 450 °C (842 °F) | NIOSH | ||
| Density | 1.8 g/cm³ | amorphous | HSDB |
| 2.46 g/cm³ | NIOSH | ||
| Solubility | Slowly soluble in 30 parts cold water; slowly soluble in 5 parts boiling water; soluble in alcohol, glycerol | HSDB | |
| Water solubility: 4.0% at 20 °C | at 20 °C | HSDB | |
| 2.77 g/100 g water at 20 °C. | at 20 °C | HSDB | |
| Vapor pressure | 0 mmHg | approx | NIOSH |
| Lower explosive limit (LEL) | Noncombustible Solid | NIOSH | |
| Corrosivity | Very corrosive to metals in the presence of oxygen | HSDB |
Values compiled from PubChem Laboratory Chemical Safety Summary. Temperatures converted to Fahrenheit for reference.
04 · Handling and storage
Storing and handling Diboron trioxide
Storage conditions
Dry.
Source: Hazardous Substances Data Bank (HSDB)
Incompatible materials
Attacks metal in the presence of moist air.
Source: Hazardous Substances Data Bank (HSDB)
Reactivity
BORON OXIDE is non-combustible. Of generally low chemical reactivity. Reacts exothermically but slowly with water to form boric acid, a weak acid. Reacts exothermically with strong bases. May react with strong reducing agents such as metal hydrides, metal alkyls to generate flammable or explosive gases. May react violently on contact with bromine pentafluoride. Corrosive to metals in the presence of air.
Source: CAMEO Chemicals
Planning storage for a mix of chemicals? Check Diboron trioxide in the storage compatibility matrix →