Diborane

Poison by inhalation. An irritant to skin, eyes, and mucous membranes comparable to chlorine, fluorine, arsine, and phosgene. The liquid causes local inflammation, blisters, redness, and swelling. Injuries to central nervous system, liver, and kidneys have also been produced in experimental animals. Similar observations have been reported in humans, resulting at times in a reaction resembling metal fume fever. Human exposure to pentaborane has produced signs of severe central nervous system irritation such as drowsiness, dizziness, visual disturbances, muscle twitching, and in severe cases, painful muscle spasm. Dangerously flammable when exposed to heat or flame or by chemical reaction. On contact with moisture, hydrogen is usually evolved. Highly explosive when exposed to heat or flame. Explosive reaction with air, tetravinyllead, O2 above 165°C, octanol oxime + sodium hydroxide, benzene vapor, HNO3Cl2. Violent reaction with halocarbon liquids. Other boron hydrides evolve H2 upon contact with moisture or can propagate a flame rapidly enough to cause an explosion. Heat can cause these materials to decompose violently or at least to evolve H2. They also react with water or steam to evolve hydrogen. Reaction with Al or Li forms complex hydrides that may ignite spontaneously in air. Powerful oxidizing agents, such as chlorine gas, etc., can react violently with boron hydrides. Pentaborane (stable) is spontaneously flammable in air. See also BORANES and HYDRIDES.Analytical Methods: For occupational chemical analysis use NIOSH: Diborane, 6006.