Assuming makes life easier. Assuming I won’t get hurt because “I know what I’m doing” and “following the procedure” and “somebody else has taken care of the hazard” gets things done quicker, but not always safely.
Those assumptions probably were made by two technicians assigned to remove blind flanges from an out-of-service pipeline in a refinery. They knew what they were doing, they were following the procedures, and someone else had taken all the necessary precautions for them.
Still, they mistakenly broke open the wrong line, an adjacent one still in service containing hydrogen sulfide.
They were outfitted in protective suits with an air supply, but in making their emergency escape, one was killed by exposure to the toxic gas.
Contractors died from hydrogen sulfide poisoning during October leakThe event is still under investigation, but there are two known facts that serve as important lessons.- Because protective outer clothing and supplied breathing air was required, the usual requirement to wear an H2S monitor was not required. So, H2S monitors were not worn.
- Instead of the line identification tags being attached to the blind flange, they were attached to a nearby handrail.
Paul Balmert
April 2025