A RESEARCH TO DEVELOP A PREDICTING SYSTEM OF MAMMALIAN SUBACUTE TOXICITY .1. PREDICTION OF SUBACUTE TOXICITY USING THE BIOLOGICAL PARAMETERS OF ACUTE TOXICITIES

Predicting equations of subacute toxicity were developed by analyzing rat acute and subacute toxicity data of 56 chemicals of various struct ures. Minimum or 10% effect level in acute or subacute toxicity was es timated as a ''biological parameter''. Good regression equations were established between the geometrical means (''combined parameters'') of any two of the parameters of acute and subacute toxicities and introd uction of log P to the equations improved the correlations with a stat istically significant multiple regression coefficient. The lowest pred icted effect level of the subacute toxicity, which is selected from th e data calculated by the above several correlations, can predict the u pper limit of the no observed effect level.