The following abstract presents results of a study conducted by a contract laboratory for the National Toxicology Program. The findings have not been peer reviewed and were not evaluated in accordance with the levels of evidence criteria established by NTP in March 2009. The findings and conclusions for this study should not be construed to represent the views of the NTP or the U.S. Government.
Glycidol is a viscous, colorless liquid which is used primarily as a stabilizer in the manufacture of vinyl polymers. It is also used as an intermediate in the production of pharmaceuticals and as an additive for oils and synthetic hydraulic fluids. Over 10 million pounds of GCD compounds are produced or imported annually.
Glycidol was nominated to the NTP for toxicological evaluation and was selected for immunotoxicity studies by the chemical manager. Thus, the purpose of this range-finding study was to determine the doses of GCD to be used in the protocol to determine the potential effects of glycidol on the immune system.
The range-finding studies were conducted in female B6C3F1 mice. The animals were administered glycidol daily for 14 days by oral gavage. Glycidol was prepared as a solution in sterile distilled water. Two studies were carried out in completing the range-finding protocol. Study 1 utilized glycidol doses of 25, 50, 75, 100, 125, 150, 200, 250, and 300 mg/kg. Based on the results of Study 1, higher dose levels were used in Study 2. The dose levels of glycidol used in Study 2 were 50, 125, 200, 300, and 400 mg/kg.
The results of the glycidol range-finding studies demonstrate that in the female B6C3F1 mouse exposure to glycidol, administered by oral gavage for 14 days at doses of 300 mg/kg or greater, results in overt toxicity and death of the animals. However, exposure to lower doses of glycidol, including those which do not produce a decrease in body weight, body weight gain, spleen weight or spleen cellularity, are associated with a reduction in the IgM response to sheep erythrocytes. Based on the toxicological and immunological results of this range-finding study, doses of 25, 125, and 250 mg/kg will be used in the glycidol protocol study.