DR. IRON Plant Food, 40 lb, Bag, Solid, Dark Gray, Compositions: Sulfur, Magnetic Iron Oxide, Bentonite, Silicon Dioxide, Titanium Dioxide, Aluminum Oxide, Calcium Oxide, White Phosphorus, Magnesium Oxide, Flash Point: 188 deg C, Boiling Point: 444 deg C, Flammability Rating: 1, Specific Gravity: 2.07