Spotlight on Safety: To Err is Human, To Forget is Disastrous

“Almost all the major accident investigations — Texas City, Piper Alpha, the Phillips 66 explosion, Feyzin, Mexico City — show human error as the principal cause, either in design, operations, maintenance, or the management of safety” (1). It is easy to blame the human for the error, but this will not prevent the incident from reoccurring.

According to the Center for Chemical Process Safety (CCPS) Process Safety Glossary, human factors can be defined as: “A discipline concerned with designing machines, operations, and work environments so that they match human capabilities, limitations, and needs” (2). Thus, the recommendations of incident investigations should address the human factors that led to the incident. It is important to embed the lessons learned from these incidents, including the human factors associated with them, in the organization’s process safety management system. If not, humans may commit the same error again, leading to disastrous consequences.

In my early career, I had three near-death experiences while operating plants, all rooted in human error and its associated human factors.

Incident 1. The primary reformer of an ammonia plant had an outlet collection header that was configured with a T joint. The header was lined with refractory. The gas temperature was 765°C, the pressure was 32 bar gauge, and the outlet stream consisted of about 66% hydrogen. Due to cracks in the internal refractory of the...