Earlier this week I posted about how a PHA should document its consideration of the engineering controls and administrative controls failing. And I said back in the 2013 posting; this little requirement is intended to make facilities dig past a single layer of protection and maybe even identify a lack of engineering and/or administrative controls for a process deviation. But let’s be clear, a Process Hazard(s) Analysis is a SINGLE TOOL we use to identify “hazards” of our process and the safeguards we have in place to PREVENT the scenario from initiating, PROTECTING assets once the event has occurred, and then MITIGATING the consequences of the event. In my post earlier this week, my layers began at the OPERATIONAL LEVEL of process control. What do I mean by this?
Our true FIRST layer of protection against a Loss of Primary Containment (LOPC) event is the actual PRIMARY CONTAINMENT. Using the same scenario of HIGH PRESSURE in a vessel, as I did in my earlier posting, we should ALREADY HAVE engineered and analyzed the consequences of deviation from the DESIGN when we were establishing our Process Safety Information (PSI)…
1910.119(d)(2) Information pertaining to the technology of the process.
…
1910.119(d)(2)(i)(D) Safe upper and lower limits for such items as temperatures, pressures, flows or compositions; and,
1910.119(d)(2)(i)(E) An evaluation of the consequences of deviations, including those affecting the safety and health of employees.
We know this must be done BEFORE we even begin our PHA, because of…
1910.119(d) Process safety information. In accordance with the schedule set forth in paragraph (e)(1) of this section, the employer shall complete a compilation of written process safety information before conducting any process hazard analysis required by the standard.
So the reason I do not look at the pressure vessel catastrophically failing due to HIGH PRESSURE during the PHA is because the facility is supposed to have ALREADY done this analysis when they were putting their PSI together (e.g. .119(d)(2)(i)(D) and .119(d)(2)(i)(E)). But the vessel itself is ABSOLUTE KEY to process safety, and during the PSI compilation, we should have been challenging our process design even BEFORE this vessel was ordered!
For example,