Sodium nitrate

NaNO₃

Sodium nitrate is a white crystalline solid. Noncombustible but accelerates the burning of combustible materials. 

If large quantities are involved in fire or the combustible material is finely divided an explosion may result. May explode under prolonged exposure to heat or fire. Toxic oxides of nitrogen are produced in fires. Used in solid propellants, explosives, fertilizers, and for many other uses.