Regulatory safety testing of chemicals and materials is still mainly focused on animal testing. A huge number of New Approach Methodologies (NAMs) to replace or reduce animal testing have been scientifically developed within the last years. Their regulatory use, however, is still limited. A possible way to include NAMs into regulatory testing may be found in Adverse Outcome Pathways (AOPs). We will present what AOPs are, how they can be developed and established at OECD. The AOP for pulmonary fibrosis and the AOP on acute lung toxicity will serve as examples for the development of nanomaterial-relevant AOPs. We will discuss the implementation of AOPs into regulatory testing and hurdles. … more …