Prediction of Human Lethal Doses and Concentrations of MEIC Chemicals from Rodent LD <sub>50</sub> Values: An Attempt to Make Some Reparation
John C. Dearden, Mark Hewitt
Abstract
The prediction of human toxicities from animal toxicity tests is often poor, and is now discouraged and in some cases banned, especially those involving the LD 50 test. However, there is a vast number of historical LD 50 data in both public and in-house repositories that are being put to little use. This study examined the correlations between human lethality (doses and concentrations) of 36 MEIC chemicals and the median values of a large number of mouse and rat LD 50 values obtained for four different routes of administration. The best correlations were found with mouse and rat intraperitoneal LD 50 values (r 2 = 0.838 and 0.810 for human lethal dose, and r 2 = 0.753 and 0.785 for human lethal concentration). The results show that excellent prediction of human lethal dose and concentration can be made, for this series of chemicals at least, by using uncurated rodent LD 50 values, thus offering some reparation for the millions of rodent lives sacrificed in LD 50 testing.