Chemical Name CAS-Number |
Physical |
Chemical |
UN Class or Division / Subsidiary RisksChemical |
BORON OXIDE |
Reacts slowly with water to form boric acid • Corrosive to metals in the presence of oxygen |
8 |
|
BORON TRIBROMIDE |
The vapour is heavier than air |
May explode on heating • The substance decomposes on contact with alcohol producing toxic and corrosive fumes (hydrogen bromide) • The solution in water is a strong acid, it reacts violently with bases and is corrosive to metals, rubber and wood • Reacts violently with water producing hydrogen gas, causing explosion hazard |
2.3/ 8 |
BORON TRICHLORIDE |
The gas is heavier than air |
Reacts violently with water • On contact with air it emits hydrogen chloride • Attacks many metals in presence of water |
2.3/ 8 |
BORON TRIFLUORIDE |
The gas is heavier than air |
The substance will polymerize unsaturated compounds • The substance decomposes on contact with water and moisture, producing toxic and corrosive fumes including hydrogen fluoride, fluoroboric acid and boric acid • Reacts violently with metals such as sodium, potassium and calcium, and with alkyl nitrates • Attacks many metals in presence of water |
8/ 3 |
BORON TRIFLUORIDE ETHERATE |
4.1/ 6.1 |
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DECABORANE |
Dust explosion possible if in powder or granular form, mixed with air |
May explode on heating or contact with flames • The substance decomposes slowly on heating to 300°C to form boron and the flammable gas, hydrogen, and on burning producing toxic fumes (boron oxides) • Reacts with halogenated materials and ethers to form impact-sensitive materials • Undergoes explosive reaction with oxidants • Reacts with water or moisture to form flammable gas • Attacks natural rubber, some synthetic rubbers, some greases and some lubricants • Ignites in oxygen at 100°C • Reacts with amides, acetone, butyraldehyde, acetonitrile at room temperature |
2.3/ 2.1 |
DIBORANE |
The gas mixes well with air, explosive mixtures are easily formed • Will ignite spontaneously in moist air at room temperature |
The substance will polymerize to form liquid pentaborane • The substance decomposes at red heat to boron and hydrogen, and at lower temperatures to hydrogen and boron hydrides • Reacts spontaneously with chlorine and forms hydrides with aluminum and lithium which may ignite spontaneously in air • Reacts with many oxidized surfaces as a strong reducing agent |
4.2/ 6.1 |
PENTABORANE |
The vapour is heavier than air |
The substance decomposes slowly on heating to 150°C to form boron and the flammable gas hydrogen, and on burning producing toxic fumes (boron oxides) • Reacts with oxidants and halogens causing fire and explosion hazard • Impure material ignites spontaneously in air • Shock-sensitive solutions are formed with solvents such as ketones, ethers, esters |
4.3 |
SODIUM BOROHYDRIDE |
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SODIUM TETRABORATE DECAHYDRATE |
The substance decomposes on heating above 400°C producing metaborates • The substance is a weak base |
3 |
|
TRIMETHYL BORATE |
The vapour is heavier than air and may travel along the ground; distant ignition possible |
On combustion, forms toxic gases of carbon and boron oxides • Reacts with oxidants causing fire and explosion hazard • Reacts with water, moist air and acids to form methanol and boric acid |
For UN Class: 1.5 = very insensitive substances which have a mass explosion hazard; 2.1 = flammable gas; 2.3 = toxic gas; 3 = flammable liquid; 4.1 = flammable solid; 4.2 = substance liable to spontaneous combustion; 4.3 = substance which in contact with water emits flammable gases; 5.1 = oxidizing substance; 6.1 = toxic; 7 = radioactive; 8 = corrosive substance