Manganese 2 : A metallic element (Mn) which is flammable in dust or powder form and will damage the central nervous system if inhaled over a prolonged period
Ralph W. Burklin & Robert G. Purington, Fire Terms: A Guide to Their Meaning and Use, National Protection Association, Boston, MA 1980 USA. (Guide: Meaning and Use, Nat Prot Association Fr Srvc - Amer) {457}