Navigation path


Public Health (24-11-2008)

Public consultation: Use of the Threshold of Toxicological Concern (TTC) approach for the safety assessment of chemical substances

The Threshold of Toxicological Concern (TTC) approach is a risk assessment tool establishing a threshold value for human exposure to chemicals which can be considered safe. According to this approach, a safe level of exposure can be identified for many chemicals based on their chemical structure and the known toxicity of chemicals which share similar structural characteristics. The TTC approach can be used in situations where there is limited or no information on toxicity of a compound, and where the human exposure is so low that adverse effects are not expected.
The TTC concept is currently used in relation to oral exposure to food contact materials, food flavourings and genotoxic impurities in pharmaceuticals. The application of the TTC approach in a variety of other areas is currently under discussion and as a result the European Commission asked the Scientific Committees on Consumer Products (SCCP), Health and Environmental Risks (SCHER), and Emerging and Newly Identified Risks (SCENIHR) to critically review the available scientific literature on the use of TCC approach. In particular, the Committees were asked to examine the applicability of the TTC approach in the human health risk assessment of chemical substances and the safety evaluation of cosmetic ingredients.
The preliminary report of the Scientific Committees indicates that the principle of the TTC approach in itself is scientifically acceptable. However, the applicability of this principle for risk assessment in specific areas is dependent on the quality, quantity and relevance of the underlying toxicity database and a reliable estimation of the exposure to the chemical.
The preliminary report is published on the SANCO website and stakeholders are invited to comment through an online consultation, aimed at gathering feedback on the scientific evidence and conclusions drawn by the Scientific Committees. The deadline for the public consultation is 2 January 2009.
For more information on the preliminary report and on how to submit your comments, please visit: 
For more information on the Scientific Committees, please visit: