Safety Statements: A poison by inhalation and ingestion. The powdered sulfide ignites spontaneously in air and some air-powder mixtures may be explosive. Trace carbon lowers the ignition temperature in air to 228°C and increases the sensitivity of air-dust mixtures. Heats up spontaneously and ignites with combustibles. Incompatible with water. When heated to decomposition or in reaction with acid or acid fumes it emits very toxic fumes of SOx. See also IRON COMPOUNDS, SULFIDES, and HYDROGEN SULFIDE.