I was recently standing with several colleagues on the mezzanine level of a small batch manufacturing plant watching an operator charge LiOH-H2O into a reactor manway. Without warning we were all suddenly hit with a punch to the throat from inhalation of invisible caustic dust that had aerosolized during the charging, and we were forced to evacuate to the outside. LiOH is every bit as caustic as NaOH, but the monohydrate is a free-flowing powder and tends to form dust. The operator, in full respirator and other PPE was unaffected and unaware of the hazard created by his actions. For the rest of us, the discomfort was significant and lasted for some time afterwards, and could have been much worse.
This operation had been carried out multiple times before without incident. In this particular case however, the difference was that the scrubbing tower was not operating. The scrubber is tied to the reactor vent and draws room air through the manway when it is open, which prevents any significant dust from entering the room. It is generally operational during any chemical operations to prevent workplace exposures and minimize fugitive emissions.
It was an experienced operator who had gone around the plant in the morning turning on all the utilities for the batch as he had done many times before, but failed to turn on the scrubber. The real offense was that he then took the batch record pre-startup checklist, which included things such as ensuring that the bottom valve was closed, scrubber was operating, etc., and simply checked off all the boxes. As the plant owner later remarked, he “pencil-whipped it”. That’s a term I didn’t recall hearing before, but it refers to the practice of running down a checklist and checking off all the boxes without actually doing the checks, or approving a document without actually reviewing it. Much has been written about it as a safety and quality problem [1].
It’s easy to see how pencil-whipping could have serious consequences including injury or worse. Under the right circumstances it can be considered criminal. In the chemical industry, even the most highly trained and experienced operators can fall victim to complacency. That’s why safety experts suggest changing things up a little bit over time for existing processes, or when writing batch records for new processes. Having a second person as a checker can be helpful if properly enforced. I think one of the best suggestions I’ve heard is that rather than having the operator check a box, force them to write down a value. Thus, instead of a box to check confirming that the scrubber was operating, the batch record could have had a space to record scrubber operating temperature, water level, or operating pressure. It’s a good principle to keep in mind to combat the effects of complacency in the workplace.
Finally, the operator needs to be made aware of his omission, but placing the blame on him alone is seldom productive. Handled properly, it can be a valuable teaching moment for all, and a good reminder that we all need to be vigilant, and constantly strive to develop the most effective operating and safety procedures and documents that we can.
- Ludwig,, The Anatomy of Pencil Whipping, Professional Safety (www.asse.org) p47 Feb 2014
