Risk Assessment in the 21st Century: New Technologies and Techniques

Abstract The first section of this chapter examines efficient alternatives to animal testing that enhance animal welfare and decrease the costs of experimental testing. Various U.S. agencies have focused on research programs such as ToxCast and “Tox21.” These alternatives include high-throughput (HTP) cell-based “-omics” technologies, in silico methodologies, and 3D “organ-on-a-chip” cell models. These programs aim to develop in vitro methodologies to evaluate and prioritize chemicals for future animal testing based on concerns about their toxicological effects, which have generated data sets far exceeding management capabilities. The second section of this chapter discusses the weight of evidence (WOE) approach used by authoritative bodies to assess the validity of the scientific reasoning taken from a given body of evidence. This is typically in circumstances where there is an appreciable level of uncertainty, and is used to determine whether the supporting evidence for one side of the case or other is greater after an unbiased assessment.