Characteristics: Gray metal or black powder. Does not occur free in nature. A necessary trace element in plant nutrition. Insoluble in hydrochloric or hydrofluoric acid, ammonia, sodium hydroxide, or dilute sulfuric acid, soluble in hot concentrated sulfuric acid or nitric acids, but insoluble in water. High strength at very high temperatures. Oxidizes rapidly above 1000°F in air at sea level, but is stable in upper atmosphere. Low toxicity.
Hazards: Flammable in form of dust or powder. Tolerance of Mo compounds (as Mo); insoluble, 10 mg/m3 of air; soluble, 5 mg/m3 of air.