The uptake and elimination of Cr VI in a male volunteer who ingested 2 L d of water containing 2 mg L for 17 consecutive days was measured Total chromium was measured in urine plasma and red blood cells RBCs for 4 d prior to and 2 wk after dosing 34 d total The estimated bioavailability 2 and the plasma elimination half life 36 h were consistent with our previous studies of Cr VI ingestion in humans Steady state chromium concentrations in urine and blood were achieved after 7 d of Cr VI ingestion Both plasma and red blood cell RBC chromium concentrations returned rapidly to background levels within a few days after cessation of dosing Since the concentration of chromium in the RBC should not decrease quickly if the chromium had entered the RBC as Cr VI these data support our prior work suggesting that concentrations of 10 mg Cr VI L or less in drinking water of exposed humans appears to be completely reduced to Cr III prior to systemic distribution Clinicalchemistry data indicate that no toxicity occurred