412316-00-8 7440-58-6 Celtium EINECS 231-166-4 HAFNIUM HSDB 552 Hafnium and compounds Hafnium powder, dry [UN2545] [Spontaneously combustible] Hafnium powder, wetted with not <25 water (a visible excess of water must be present) (a) mechanically produced, particle size <53 microns, (b) chemically produced, particle size <840 microns [UN1326] [Flammable solid] Hafnium, elemental UN1326 UN2545