December 4, 2017

Big data and process safety

There is a lot of action going on in the big data field and how it will help us improve process safety. I have operated chemical plants in the 80's and 90's and what I have observed is that the data flow to an operator in a control room has dramatically increased today, when compared to the past. Consequently he/she is now prone to making more errors. Adopting Dr Trevor Kletz' approach of inherent safety, could we pose a all the data really necessary? While technology is definitely an enabler, one has to draw a line between good data (useful data) and bad data (unwanted data that distracts operator attention).......what I mean is that while many of the modern control systems do have very useful features, we must filter out the data we do NOT want, at the design stage of the control system itself. As an example, if we restrict the number of alarms in the design stage itself, why do we need alarm management software to be retrofitted? Your thoughts, please.....

December 3, 2017

Black swans and good safety management systems

Reuters has reported an accident at an Exxon Mobil refinery project site on Friday, when a young female worker was killed when, reportedly, a pipe fell on her. Read about the incident in this link

Exxon Mobil have very good safety management systems, yet this incident has taken place. I see such black swan events in other well and safely managed companies too. Why do you think such black swan events occur?

Bhopal - Lessons only partly learnt

Today is the 33rd anniversary of Bhopal. But we, In India have only partly learnt the lessons from Bhopal.

December 1, 2017

Hot in Cold equals Explosion!

A hot aqueous process stream was wrongly directed to a tank full of cold hydrocarbon. The heat input from the aqueous stream caused rapid vaporisation of the hydrocarbon which then over-pressured the tank and caused a failure of the roof seam.

November 28, 2017


One worker died due to inhalation of H2S while trying to take out a safety valve for maintenance. It was later determined that he removed the flange bolts of the wrong relief valve and he was working without a permit. His supervisor had pointed to the safety valves (there were two of them at a height) and told him to remove one. He assumed the worker knew which valve to open.