PROSPECTIVE KAPPA-E SCREENING OF POTENTIAL CARCINOGENS BEING TESTED IN RODENT BIOASSAYS BY THE UNITED-STATES NATIONAL TOXICOLOGY PROGRAM

Values of k(e), the rate constant of electron attachment, were measured in cyclohexane for 31 of 44 chemicals now being screened for carcinogenicity in rodent bioassays conducted by the US National Toxicology Program (NTP). These k(e)s provide a physico-chemical measure of electron-solute interaction in a non-polar medium which had been found to be correlated with solute carcinogenicity in our earlier studies of the k(e)s of chemical carcinogens and putative non-carcinogens. The k(e) test yields 15 negative and 16 positive responses for the 31 chemicals that were screened in this study. These k(e) results are compared with the predictions of other carcinogen-screening methods that have been applied to the same chemicals and also reported in this Discussion Forum.