In Safety Moments #2: Common Process Hazards — Static Electricity and #7: No One There it was noted that the only way of achieving perfect safety is to remove people from the location of the hazard. We adapt one of Trevor Kletz’s phrases by saying, “If a person’s not there they can’t be killed.”
The value of this saying is illustrated here with two more events. Both were serious — and had the potential to kill the persons involved. Fortunately, there were no injuries in either case.
The Leaking Pump
On a refinery in California a supervisor was walking past a set of two pumps (one was a spare). The materials being pumped was highly flammable. Just as he was going by one of the pumps blew a seal and large vapor cloud formed. The supervisor had, at one time, been in charge of the unit he was walking through, so he knew the equipment very well. But, at the time of the incident, he was working elsewhere; he did not have line authority over the unit in question.
The supervisor was faced with an on-the-spot decision. Should he walk quickly over to the pumps, shut down and block in the leaking pump and start the spare. Doing so would mean that the total amount of material leaked would be minimized and he could keep the unit running with minimal interruption. On the other hand, had the leaking vapor ignited — and there were fired heaters in the vicinity — he would likely have been seriously injured or even killed. The alternative decision was to move away from the situation, then go to the control room and inform the line operators that there was an emergency situation.
The decision he made was to go toward the leaking pump and shut it in. He then went to the control room where the senior operator triggered the refinery alarm systems, and the emergency response team went to the pumps to make sure that there were in fact blocked in and not leaking.
As a result of the supervisor’s action the event was not much more than a minor release and production upset. But the consequences could have been much, much worse.
The Failed Gasket
At another refinery, this one in Texas, an operator was changing out a filter in a line through which flowed light hydrocarbons. His actions were completely routine — this was an activity that he had done many times before. He installed a new filter cartridge, put a new seal on the top of the filter housing, closed up the filter body and opened the valves around the filter so restart the flow of hydrocarbon liquid.
When he did so the new gasket failed catastrophically and a large amount of liquid sprayed out, soaking him for head to foot. All around were fired heater, any one of which could cause the leaked materials to ignite. The operator did not attempt to control the leak; instead he ran away from the scene. And then, after he had run a good distance, he stopped, stripped off many of his contaminated clothes and then kept on running.
The leaking material did light off; the resulting fire was very large and led to serious damage. But no one was injured.
When faced with events such as these no one knows what they would actually do on the spur of the moment. In the first case the supervisor moved toward the hazardous situation, in the second case the operator moved away.
On reflection it is probably fair to say that the supervisor in the first case should not have approached the leaking pump. But, to repeat, we none of us know what we would do in an actual situation.
(One final thought to do with this event — why did the new gasket fail? It turned out that it was of the wrong specification. There appears to have been a Management of Change failure in the warehouse.)