Skip Ribbon Commands
Skip to main content

Threshold of Toxicological Concern

Background and Objectives

In 1995, the US Food and Drug Administration (FDA) introduced the Threshold of Regulation (ToR) program, according to which, at sufficiently low enough exposure, the associated risk related to the consumption of substances used in food contact articles (food packaging and food processing equipment) may be deemed negligible. Derived from the ToR, the Threshold of Toxicological Concern (TTC) concept is a pragmatic but conservative science-based tool to help regulators and industry assess potential health risk from substances when specific toxicological data are not yet available (R. Kroes, et al. 2000).


Since 1996, ILSI Europe has played a major role in advancing and promoting a broad application of the TTC concept in Europe. The scientific approach of the TTC concept was recognised by the scientific committees of international authorities, which released favourable opinions on the use of TTC as a risk assessment tool. The use of the TTC principle enables to:

  • Recognise that exposures lower than the TTC levels do not pose safety concerns;
  • Decrease the use of laboratory animals;
  • Better use of financial and human resources in both industry and governments;
  • Apply a practical risk assessment tool correlated to more and more sensitive analytical techniques.
For more detailed information, please contact Dr Alessandro Chiodini at



  • EU-project COSMOS: Integrated In Silico Models for the Prediction of Human Repeated Dose Toxicity of Cosmetics to Optimise Safety