Scope Statement

Estimates for the needs of animals for in vivo testing for nanomaterials exceed what is considered reasonable in any modern society. Indeed, more and more emphasis is given towards the need to reduce reliance on animal models via the development of alternative (in vitro) test methods and development of quantitative structure-activity relationships (QSARs) for nanomaterials.

With thousands of new materials emerging, as well as thousands of variants of these materials, there is an urgent need for agreed concepts of how to predict likely impacts on human health based on relationships between physico-chemical properties, properties of nanomaterials in situ under relevant exposure conditions, and for identification of connections between those properties with impacts from studies done on previous materials. In the short term, more data using in vitro tests are needed and high-throughput screening (HTS) may prove useful; in addition, thorough material characterization is key. Approaches such as pattern recognition, neural networks, microscopic / semi-microscopic and mechanistic and phenomenological models need to be developed and compared to each other and to extensive in vitro and limited in vivo tests for validation purposes to establish their predictive power and their applicability to existing and emerging nanomaterials for which there are limited toxicity data available.