Determining the Applicability of Threshold of Toxicological Concern Approaches to Substances Found in Foods

Abstract

Threshold of Toxicological Concern (TTC) decision-support methods present a pragmatic approach to using data from well-characterized chemicals and protective estimates of exposure in a stepwise fashion to inform decisions regarding low-level exposures to chemicals for which few data exist. It is based on structural and functional categorizations of chemicals derived from decades of animal testing with a wide variety of chemicals. Expertise is required to use the TTC methods, and there are situations in which its use is clearly inappropriate or not currently supported. To facilitate proper use of the TTC, this paper describes issues to be considered by risk managers when faced with the situation of an unexpected substance in food. Case studies are provided to illustrate the implementation of these considerations, demonstrating the steps taken in deciding whether it would be appropriate to apply the TTC approach in each case. By appropriately applying the methods, employing the appropriate scientific expertise, and combining use with the conservative assumptions embedded within the derivation of the thresholds, the TTC can realize its potential to protect public health and to contribute to efficient use of resources in food safety risk management.

Keywords:

• Food safety
• risk management
• threshold of toxicological concern
• TTC

ACKNOWLEDGMENTS

This work was supported by the Technical Committee on Food and Chemical Safety of the North American Branch of the International Life Sciences Institute (ILSI North America). Authors Greg Paoli and Margaret Wilson served as consultants to this project and received funds from the ILSI North America Technical Committee on Food and Chemical Safety for their work on this paper.

ILSI North America is a public, nonprofit foundation that provides a forum to advance understanding of scientific issues related to the nutritional quality and safety of the food supply by sponsoring research programs, educational seminars and workshops, and publications. ILSI North America receives support primarily from its industry membership.