Research has shown that arsenites (trivalent forms) have a higher acute toxicity than arsenates (pentavalent forms).[2] The acute minimal lethal dose of arsenic in adults is estimated to be 70 to 200 mg or 1 mg/kg/day.[3] Most reported arsenic poisonings are not caused by elemental arsenic, but by one of arsenics compounds, especially arsenic trioxide, which is approximately 500 times more toxic t