Goals of Genetic Toxicology in Chemical Safety Evaluation

The Goals of Genetic Toxicology in Chemical Safety Evaluation 

Approaches for Assay System Deployment in the Identification of Genotoxic Substances 

The approaches employed by various testing laboratories cover a broad spectrum of philosophies. Some approaches rely completely on in vitro methods, some primarily on in vivo methods, and some on a mixture of the two.  

Numerous approaches have been proposed ranging from hierarchical schemes (tier approaches) oriented toward mass screening to matrix schemes oriented toward obtaining a complete data profile on limited numbers of compounds. The application of either scheme will depend to a great extent on the nature of the substance to be tested and its development progress. Tier systems are most often applied to screen out those materials that are inactive and evaluate those with activity in more rigorous tests. The numbers of chemicals 

While all methods of test deployment seek to provide reliable information, there are several basic problems that have been uniformly encountered. Most approaches to chemical testing fail to distinguish between detection and risk assessment. These are two distinct functions and require different types of assays. The detection of genotoxic properties in a test sample does not a priori imply risk. Detecting systems define the inherent potential of a test substance to damage DNA, but do not demonstrate that the potential will be expressed in vivo under environmental exposure conditions. Submammalian and in vitro mammalian assays are typically used to detect genotoxic potential. 

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