Abstract
Skin sensitization risk is an important toxicological endpoint as part of safety assessment of chemical substances. In place of conventional animal-based testing methods for identifying and characterizing skin sensitization hazards, New Approach Methodologies (NAMs) have been developed for risk assessment of chemical substances, and the Next Generation Risk Assessment (NGRA) using these methods is being actively developed.
Several in chemico and in vitro testing methods have been developed for skin sensitization NAMs, focusing on key events in the early stages of sensitization, and have been adopted as OECD test guidelines. In addition, several in silico tools have been developed. More recently, the Defined Approaches for Skin Sensitization (DASS) have been proposed to cover the inherent complexity of processes underlying skin sensitization with high predictivity. Currently, the 2 out of 3 Defined Approach and Integrated Testing Strategy v1/v2 Defined Approaches are included in the OECD guidelines. This presentation will introduce these NAMs for skin sensitization, focusing on those newly adopted or updated in the OECD guidelines, and discuss their current status of regulatory use in the evaluation of skin sensitization of chemicals and cosmetic ingredients.
In using NAMs as part of NGRA for skin sensitization, there are some points to be considered and cautions to be taken into account, such as the applicability domains or limitations of each NAMs. In this presentation, the issues of NAMs for the future development of NGRAs and the latest research topics that are currently being actively studied to solve these issues will be introduced.
