Two of my major chemical incidents in my career occurred during “demo work” in a process that we were certain was gas-free/zero energy state. And of course, we were wrong! Highly toxic/flammable gases can travel long ways to places we never thought possible and do some serious damage to people and property when they get released. Here is an OSHA case where the workers were bit by the “demo” mindset, assuming the process, albeit a very small one, was energy-free…
This is also a story of a contractor being allowed to make “line breaks” on a process involving chlorine! Although NOT a PSM or RMP covered process, I hope we have passed the idea that “line breaks/process openings” are only dangerous when the process exceeds the PSM/RMP TQs.