Three-Tier Inherent Safety Quantification (3-TISQ) for Toxic Release at Preliminary Design Stage

Inherent safety is an approach that is aim to minimize or eliminate the main causes of the hazards by adjusting the design of the chemical process plant instead of depending on the existing safety systems of the equipment and procedure of the process. Even though the present facilities and operating procedures has provided the safety engineered system and cost performance, the actual implementation of inherent safety in process design stage has not been commonly implemented in the industries. Current research and development are mainly specifically for explosion and fire cases only. None of these methods were developed to reduce or prevent the major accidents due to toxic release accidents. Therefore, this paper proposes a new technique to evaluate the level of inherent safety of process plant during the preliminary design stage by using the combined assessment of process routes, streams and inherent risk for toxic release accidents. This technique is known as 3-Tier Inherent Safety quantification (3-TISQ). The 3-TISQ technique is able to quantify and prioritize the level of inherent safety of the process route and stream, determine the inherent risk and modify the design up to acceptable level during the preliminary design stage.