One of the most dangerous tasks that occur within the battery limits of a covered process is “opening the process.” This is commonly called a “Line Break” but also applies to vessels. We won’t find a definition of “Line Breaking” in the PSM Standard; instead, we turn to OSHA’s Permit-Required Confined Space Standards (1910.146 and 1926.1201-.1213). During my career, one of my safety crusades has been to get businesses, even those NOT covered by PSM/RMP, to embrace the extreme hazards of opening a normally closed containment system that handles a HAZMAT. I have seen “tubing” cause fatalities, less than 3 pounds of the hazardous materials involved. So as the OSHA standards imply, “line breaking” is not simply reserved for PSM/RMP covered processes; it applies to:
| the intentional opening of a pipe, line, or duct that is or has been carrying flammable, corrosive, or toxic material, an inert gas, or any fluid at a volume, pressure, or temperature capable of causing injury. |
That is the definition from OSHA’s PRCS standards (linked above).
Call it a LOTO task or a PRCS hazard; either way, when an employee/contractor is intentionally opening a pipe, line, or duct that is or has been carrying flammable, corrosive, or toxic material, an inert gas, or any fluid at a volume, pressure, or temperature capable of causing injury, the facility should manage this task as a “Permit-To-Work” task. Never mind how much of the HAZMAT may be present! We want the containment system to be at a ZERO ENERGY STATE (ZES) and this may take some engineering and some serious planning, as many situations were not designed for “maintenance”, meaning the isolation and evacuation may need to take place a fair distance from where the break is actually going to take place. And YES, there are hazards associated with evacuating the HAZMAT and isolating the process, so they also need to be carefully analyzed and controlled.