Safety Statements: Probably a poison. A very dangerous fire hazard when exposed to heat or flame; ignites spontaneously in air. Ignites on contact with concentrated acids. To fight fire, use foam, CO2, dry chemical. Explodes on contact with chlorine; bromine; or fuming nitric acid. Can react vigorously with oxidizing materials. When heated to decomposition it emits highly toxic fumes of POx and phosphine. See also PHOSPHINE.