Chromium and hexavalent chromium

An oral dose of 2-5 g of Cr super(6+) (as a chromate compound) can be fatal to humans. Toxic symptoms in individuals ingesting at least 5 g of chromate compounds included gastrointestinal bleeding, massive fluid loss and death from cardiovascular shock. Kidney and liver damage developing 1-4 days after exposure have been reported in individuals ingesting less than or equal to 2 g of a chromate compound. For sodium chromate and dichromate, potassium dichromate and ammonium dichromate, the oral LD sub(50) in rats ranges from 51 to 57 mg/kg body weight. In terms of chromium, the LD sub(50) ranged from 16.7 to 22.5 mg/kg body weight. For chromium trioxide (chromic acid), Kobayashi reported an LD sub(50) ranging from 135 to 177 mg/kg body weight in rats (70-92 mg/kg as Cr) and from 80 to 114 mg/kg in mice (42-59 mg/kg as Cr).