“That Can’t Happen Here!” a Baker’s Dozen Idioms You Don’t Want to Hear at a Hazop

Hazard and Operability Analysis (HazOp) is one of the most popular and widely used forms of hazard evaluation in the chemical processing industry. Its structured, regimented approach and perceived thoroughness makes HazOp the methodology of choice for many companies when evaluating new plants or modifications to existing designs. Because of its widespread use and long history, there are process safety practitioners with decades of experience in both facilitating and participating in HazOp studies.

With all of this experience comes many interesting, and sometimes entertaining, “follies and fallacies in HazOp”. Statements such as “That can’t happen here!” or “That’s never happened here!” can make even the most seasoned facilitator shudder. The authors of this article, having over 40 years of combined experience in the chemical processing industries, have compiled an inventory of commonly-spoken misconceptions that are repeated in HazOp studies, irrespective of the company, industry or geographic location.

This article takes a lighthearted look at some of the more serious “follies and fallacies” in HazOp. The authors consider thirteen (i.e., a “baker’s dozen”) different distorted or erroneous statements that are often spoken during HazOp sessions. Each of these statements, in turn, is discussed with the rationale behind them and why they can lead to errors and the acceptance of intolerable risks.