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Data is needed to confidently claim a parameter value, starting with an assumed or generic value, and periodically updating that value with

While there is extensive testing and validation of hazards from flammable vapors, less information is available regarding flammable liquid mists. A method is suggested for reasonably estimating the nature and severity of flammable liquid mist hazards by applying published mist property correlations to model inputs and outputs in dispersion modeling software. Better estimating these hazards is important to properly evaluate what mitigations will be needed. One common high fla

Have you ever had the problem of having a perfectly functional BPCS * interlock that you know is highly failure immune, yet when it comes time for the Hazard Analysis, you may only take one credit? Unfortunately, for facilities following the IEC 61511 safety lifecycle, any interlock not designed according to the standard is limited to one risk reduction credit. This can make meeting extremely low total mitigated event likelihood targets (such as 1x10-5 or 1x10-6) exceedingl

STAMP ( Systems Theoretic Accident Model and Processes ) is a relatively new accident causality model based on systems theory. It draws its main tenets from systems thinking that (1) accidents can happen even when there has been no failure, (2) that interactions between components of the system create emergent properties that can lead to failure, and (3) it treats accidents as a control problem rather than a failure problem. STPA (Systems Theoretic Process Analysis) or colloq

Instrumentation, Reduction of Risk, Risk Assessment, Protection, Detection System, Alarms and Operator Interventions, Detector, Gas Detecti

Is our industry addressing the problems facing it today? We idealize infinitesimally small event rates for highly catastrophic hazards, yet are we any safer? Have we solved the world’s problems? Layers of protection analysis (LOPA) drives hazardous event rates to 10-4 per year or less, yet industry is still experiencing several disastrous events per year. If one estimates 3,000 operating units worldwide and industry experiences approximately 3 major incidents per year, the tr

This paper proposes a combined approach of discussing the cognitive psychology behind System 1 and System 2 thinking, the types of heuristic

Having a working knowledge of these five tools will improve a PHA‐LOPA facilitator’s awareness and ability to better evaluate human error re

Bayes’ Theorem is sorely missing from the toolbox of Process Safety practitioners. This paper will introduce Bayes’ Theorem to the reader an

Functional safety engineers follow the ISA/IEC 61511 standard and perform calculations based on random hardware failures. These result in...