Iron dust

Nature 
Iron dust is created in the process of mining iron ore, smelting iron and steel and processing iron and steel products, such as grinding or polishing. Iron dust if inhaled in sufficient quantities can cause pneumoconiosis of a special kind called siderosis. Finely divided freshly reduced iron powder is pyrophoric and ignites on exposure to the air at normal temperatures.
Aggravates 
Type 
(E) Emanations of other problems