Inherent safety indices for the design of layout plans

The design of the layout of chemical processes offers significant opportunities for improving safety through the implementation of inherent safety principles. However, the application of inherent safety as a guideline for layout design is seldom explored and practical support tools for the design activity are totally missing. In the current contribution, a metric is introduced to assess the safety level in the analysis of layout options. Several parameters are mapped by the indices in the metric: the hazard of the plant units, the domino hazard of the layout plan, the application of inherent safety principles, the use of traditional risk control devices and the safety economics. The framework is simple, auditable and easily applicable. Specific support rules are defined in order to reduce subjectivity in the assignation of scores. The application to a case study points out as the assessment yields effective indications by a swift procedure.