The role of inherently safer design in process safety

Abstract

The role of inherently safer design (ISD) in process safety assurance has changed significantly over the past 40 years. When first introduced by Professor Trevor Kletz following the 1974 Flixborough explosion, the ISD concept challenged the manner in which process risk was addressed in the chemical industry. The prevailing view of adding on safety devices and implementing procedures aimed at controlling hazards was now complemented by a way of thinking that sought to remove or reduce hazards at their source. The past 20 years have seen ISD mature into an established risk reduction strategy that is widely known in principle and increasingly adopted in practice. The current paper reviews the authors' collaborative research efforts aimed at integrating ISD into various process safety systems, activities, and applications. The primary inherent safety principles (minimization, substitution, moderation, and simplification) are explained with example‐based guidance provided for their use. ISD features and performance indices are examined throughout the early design and operational stages of a typical process life cycle. Preventing and mitigating undesirable occurrences such as domino effects and dust explosions are shown to be feasible by adopting an inherent safety approach. The importance of reviewing ISD case studies developed from incident investigations is also discussed. Finally, we present our personal opinions on the current status of inherently safer design and future possibilities for its continued growth.

Optimization of firefighting strategies in process plants with emphasis on domino effects and safe evacuation

“…The Point Source model, however, cannot consider the shape or tilt of the flame due to the wind effect. 1 Nevertheless, the results of the model for far-field targets (i.e., targets at distances over 10 times the radius of fire) are assumed to be of acceptable accuracy. In the present study, the Point Source model, due to its simplicity, is used to demonstrate the development of the methodology though it can be replaced by more sophisticated models without loss of generality.…”

“…In the context of fire safety in process plants, inherently safer design techniques, [1] such as Safety-by-Design, [2,3] aim to eliminate or reduce fire hazards at the design stage of vessels and processes, for instance, by reducing the inventory of flammable chemicals or by providing sufficiently long safety distances. However, when these measures fail to meet the safety requirements, additional operational and procedural measures should be taken to lower the risk of fire to a practicable level.…”

Hazard Evaluation of Metal–Organic Framework Synthesis and Scale-up: A Laboratory Safety Perspective

“…Therefore, we recommend a thorough and well-documented assessment including every laboratory step and task in the MOF synthesis process which constitutes a Job Hazard Analysis. Following industry's well-known Inherently Safer Design principles, 43 it is crucial to reduce quantities of hazardous materials in the work environment to reduce exposure and thus reduce the frequency of occurrence for incidents. With this in mind, and after analyzing the results of this study, we recommend minimizing the quantity of chemicals stored to the minimum and to follow housekeeping practices, such as not storing chemicals under a hood, instead only storing the required amounts for the synthesis work immediate to the process.…”

Safety assessment: predicting fatality rates in methanol plant incidents

“…Various researchers have studied the effect of different parameters on the production of MeOH by using CO 2 capture, such as pressure ( Bansode and Urakawa, 2014 ; Gaikwad et al., 2016 ; Gaikwad, 2018 ), temperature ( Gaikwad et al., 2016 ; Gaikwad, 2018 ), molar ratio (Bansode et al., 2014; Ghosh et al., 2021 ; Kanuri et al., 2021 ), and gas-hourly space velocity (Bansode et al., 2014, Gaikwad et al., 2016 ; Portha et al., 2017 ; Gaikwad, 2018 ; Koh et al., 2021 ; Ghosh et al., 2021 ). Processes with low operating conditions, such as temperature and pressure, are well known to be inherently safer than those with extreme conditions ( Heikkilä, 1999 ; Amyotte and Khan, 2021 ). As a rule, processes with high pressure and high temperature in combination increase the possibility of chemical leakage and thus increase the possibility of accidents, such as explosions and fires ( Srinivasan and Nhan, 2008 ).…”