Better Answers
Understanding human errors is not the finish line. It is the starting point that tells you which factors deserve examination. Better questions led to a deeper understanding of the context and the conditions faced by the two outside operators during this incident.
In the last edition, I applied the Understanding Human Actions Decision Tree to one specific action from the BP-Husky Toledo incident: opening the two-inch maintenance valve to create another drain path from the Fuel Gas Mix Drum. Using the facts in the CSB report, I classified that action as a knowledge-based mistake. That human-performance interpretation was mine, not a CSB conclusion.
The classification did not produce corrective actions. It directed attention to the performance-influencing factors that shaped the action: no established response, reliance on manual intervention, a shared but incorrect process picture, conflicting feedback, and extreme workload and time pressure.
For this newsletter, let's focus only on gas detection. Here are three aspects of the incident to examine.
Outside operators were not equipped with personal hydrocarbon detectors. Personal H2S detectors have been common in petroleum refineries for a long time. Some refineries are migrating to “four gas” detectors, which include hydrocarbon monitoring capability. Is this something your site should consider?
The fixed gas detectors near the mix drum had functioning local audible or visual alarms, and the detector functioned correctly, but wearing SCBA while completing intensive troubleshooting reduced the ability of the operators to discern the detector indications. At your facility, how do you ensure personal detectors can be noticed while wearing SCBA?
The fixed gas detector alarm to the DCS/control room was disabled by an Alarm Configuration Manager (ACM) configuration error, and the control room was already suffering from severe alarm flood. A question for each frontline leader: What is the status of the fixed gas detectors in your units right now?
The answers to these questions will lead to improved process safety at your facility. Gas detection practices are an area where, in my experience, many facilities could use improvements. I think the whole area of gas detection could be a great discussion for a future webinar. Stay tuned.
Progress on my book
A big thanks to the peer reviewers who reviewed my upcoming book “Process Safety Excellence, A Practical Reference for Operating Companies.” I received some very good constructive comments and suggestions from seasoned frontline leaders and process safety professionals. Thank you to each person who provided these comments. I'll be publishing the book in September.
For updates on the book go to hse2.com/subscribe.