​This Practice provides guidance to incorporate Inherently Safer Design (ISD) principles throughout project and operation phases. It expands upon the original four elements developed by Trevor Kletz—Substitute, Minimize, Moderate/Attenuate, and Simplify— into 7 elements with the introduction of Eliminate and the recognition of Limit Effects and Error Tolerance. This Practice defines PIP ISD principles, illustrates the value of applying ISD principles throughout each project phase and into operations, and provides tools to incorporate ISD principles to reach desired corporate target values. The tools are organized by project phase and can be used throughout the facility lifecycle, such as in Safety, Operations, and Maintenance assessments. This Practice applies to all roles. All roles share leadership, accountability, and application of ISD principles. This shared responsibility spans the entire engineering and management team beyond the process safety engineer or manager. Each team member identifies, evaluates, and incorporates inherently safer design elements within their areas of expertise. Comprehensively applying the ISD principles across roles/functions/disciplines leads to a safer process.​​
