THE BIOMETRIC EVALUATION OF THE ACUTE-TOXIC-CLASS METHOD (ORAL)

The acute toxic class method (ATC method) is an alternative to the LD( 50) test, with the use of substantially fewer animals needed for the c lassification of substances. Like the classical LD(50) test the biomet ry of the ATC method is based on the probit model. The biometric calcu lations of the ATC method were carried out not only for the classifica tion categories of the European Union but also for the classification criteria of various countries and organizations, currently in use. It is demonstrated that in comparison with the LD(50) test in general the same classification is obtained with the ATC method and with the use of substantially fewer animals. Substances with high slopes are likely to be allocated to the predicted toxicity class in comparison with su bstances having low slopes, with both the ATC method and the LD(50) te st. Substances are more likely to be allocated into a lower toxicity c lass with the LD(50) test than with the ATC method.