[Evidence-based toxicological evaluation of chemicals by group summaries]

REACH requires a certain amount of toxicological data to evaluate the registered chemicals. As a minimum, information on acute toxicity, skin and eye irritation, sensitisation, genotoxicity, organ specificity, the dose response and NOEL from repeated dose studies including toxicokinetics, reproductive toxicity and indication for carcinogenicity. In order to reduce the need for studies in animals, the use of several alternatives is proposed. In this communication the possible use of group summaries and the TTC (threshold of toxicological concern) concept are discussed. Although group summaries may bridge data gaps of structurally similar compounds by read across from better investigated chemicals, the examples presented indicate that for any group the read across needs to be thoroughly justified. The OECD documentation on group summaries provides some guidance. The TTC concept is another tool to reduce the need for animal testing. This may be applicable for compounds, for which human exposure is low and which are therefore not expected to be of relevance to human health.