The video discusses the four main components of inherently safer design as identified by the NAS study. They are substitute, minimize, moderate and simplify and are described as: 1) Substitute: replacing one material with another that is less hazardous; 2) Minimize: reducing the amount of hazardous material in the process; 3) Moderate: using less hazardous process conditions such as lower pressures or temperatures; 4) Simplify: designing processes to be less complicated, and therefore less prone to failure.