An ongoing journey toward a risk-based testing in genetic toxicology

The primary focus of genetic toxicology testing has been to predict rodent carcinogens using test batteries to qualitatively bin substances into genotoxic or non-genotoxic categories. There has been little interest in understanding the full dose response in order to identify a point of departure (PoD) value for quantitative risk assessment. This is due to the prevailing paradigm that mutagens have no thresholds. Furthermore, mutagenicity in and of itself was largely ignored as a relevant endpoint for risk assessment purposes. In recent years, however, genetic toxicologists have embarked on a journey to explore opportunities to broaden the utility of genetic toxicology information for human safety assessment. This commentary examines some of these opportunities, including the potential establishment of permitted daily exposures based on the PoD estimated from the mutagenicity data.