The following abstract presents results of a study conducted by a contract laboratory for the National Toxicology Program. The findings were not evaluated in accordance with the levels of evidence for reproductive or developmental criteria established by NTP in March 2009. The findings and conclusions for this study should not be construed to represent the views of NTP or the U.S. Government.
The potential reproductive toxicity of potassium dichromate (hexavalent) was evaluated in Sprague-Dawley rats. Potassium dichromate (hexavalent) was administered at dose levels of 0, 15, 50, 100, and 400 ppm in the diet for nine weeks followed by an eight week recovery (potassium dichromate free) period. Interim necropsies occurred after 3, 6, and 9 weeks of administration and a terminal necropsy occurred following Week 17.
There were no treatment-related findings noted in mean body weights, water and feed consumption, oragan weights, micorscopic evaluation of the liver, kidneys, and ovaries, and hematology findings except for decreases in mean corpuscular volume (MCV) and mean corpuscular hemoglobin (MCH) values in the 400 ppm males and females. These decreases suggest a possible bone marrow/erythroid response. These values returned to normal levels following the recovery period.
Testicular cell counts for Sertoli nuclei and preleptotene spermatocyte counts in Stage X and XI did not reveal any differences between the treated groups and control.
Results of the study indicate that potassium dichromate treatment did produce a slight hematopoietic toxicity at the 400 ppm dose level based upon MCV and MCH values in the 400 ppm animals. The no-observable-effect level (NOAEL) was determined to be 100 ppm.
NTIS # PB97-125355