“Ideas are commodity. Execution of them is not.”  — Michael Dell

I’ve always believed that a poor plant design, brilliantly operated and maintained, is far safer than a brilliant plant design, poorly operated and maintained. A pre-startup safety review (PSSR) is OSHA’s way of starting a facility down the path toward brilliant operation and maintenance. There is much more to it than commissioning.


Unlike the term “RAGAGEP”, which is an invention from the Occupational Safety and Health Administration (OSHA) as part of the Process Safety Management (PSM) standard, the term “PSSR” was probably not coined by OSHA. However, most people had never heard of it before it appeared in the PSM standard in 1992, and those who saw it looked at it and thought, Oh, they mean commissioning. Why didn’t they just say that? Even today, many will confidently explain, “Yeah, we commissioned the new plant as part of start-up, so of course the PSSR is done.”

There is more to a PSSR than commissioning a newly constructed facility and a PSSR is required for more than just newly constructed facilities. As long as people believe that a PSSR is just commissioning on steroids, it’s unlikely they’ll get it right, which is a regulatory issue. More importantly, it’s unlikely they’ll get the real benefit of the PSSR, which means they’ll not be as safe as they could be. That could be the real tragedy.

What is Commissioning?

An article in Processing Magazine described commissioning activities as including “cleaning, flushing, verifications, leak tests, performance evaluation and functional tests essential for bringing a newly installed plant or facility into routine operation.” It summarized this by stating that commissioning was about “the transition from construction to operation.”

Many other definitions and descriptions have been offered. They all have two things in common. First, commissioning is the last step of a project to construct a new facility. It’s the step that allows a project team to declare that it is done. Second, commissioning is the step where the construction team hands over the project to the production and maintenance departments; the step that transforms a capital project into a facility.

What is a PSSR?

A PSSR is a collection of activities that establish that it is safe for the production department to introduce hazardous chemicals into a process. It requires that construction and equipment be in accordance with the design specifications. For a new project, this is the purpose of commissioning, so clearly, commissioning is part of a PSSR.

It also requires that all the necessary procedures have been developed, that they are “in place and are adequate.” Writing the procedures is not enough. They have to be “in place”. That is, they have to be accessible to the people who need them and in a form that allows them to use them. Moreover, a PSSR doesn’t just concern itself with operating procedures, but with maintenance procedures, safety procedures, and emergency procedures. The PSSR should ensure that all of these procedures are in place before they are ever called upon to be used.  The time to develop an emergency procedure is not during an emergency.

A PSSR also demands that the facility have been reviewed for hazards and that the recommendations from those hazard reviews have been resolved or implemented. For new facilities, this means that the facility has been through a process hazard analysis. For existing facilities, this means that the facility has been through the management of change procedure.

Finally, the PSSR insists that the facility, new or modified, not be operated until each employee involved in operating or maintaining the facility has been trained. Not just on the operating or maintenance procedures, but on the hazards of the process, on how to respond to an emergency, and on how to stay safe in the first place.

When is a PSSR Required?

The PSM standard requires a PSSR for a new or modified facility whenever there are modifications “significant enough to require a change in the process safety information.” Process safety information? That includes equipment specifications, P&IDs, material and energy balances, process chemistry, and maximum intended inventory. When any of these changes, or any of the other items listed in the standard as process safety information changes, then a PSSR is required.

So, any revision to a P&ID should result in a PSSR.

When is a PSSR Needed?

The standard mentions two circumstances when PSSRs are required. The first is as part of the construction of a new facility. That is usually obvious and is why commissioning and the completion of a PSSR are often confused.

The second is for modified facilities. This means that a modification that prompts the use of the management of change procedure will likely also prompt a PSSR.

There is a third circumstance that should also prompt a PSSR. When a facility has been down for an extended period, it should go through a PSSR before being started again. When a facility is formally mothballed, it is modified in ways to secure it. A PSSR assures that the facility is properly restored to operating condition. It also assures that the production and maintenance departments are ready to resume operations.

When a facility is not formally mothballed, but simply idled, nature and entropy will begin their inexorable processes of modifying the plant. Again, a PSSR assures that the facility is properly restored to operating condition and that the production and maintenance departments are ready to resume operations.

Safety is Not in the Idea, but the Execution

Commissioning is important. It assures that ideas on paper get translated into steel and concrete. It assures that the project team has done its job. It’s the start, but not the end of process safety. A PSSR takes it further. It assures that not only has the project team done its job, but that the operating and maintenance departments are ready and have what they need to do their jobs.

A PSSR is not the last step in commissioning activity. Commissioning is the first step in PSSR activity. When the project is not the construction of a new facility, but the modification of an existing facility or the start-up of an idle facility, commissioning may not be required, but a PSSR still is. This is because a PSSR is not about the project—the idea—but about the operation and maintenance of the facility—the execution.

A Path to Brilliant Operation and Maintenance

The greatest champions for proper PSSRs should be the production and maintenance departments, the departments charged with the responsibility for safely implementing anything that is new.  Long after the project team has packed up and demobilized, the production and maintenance departments will be using the tools they have to safely operate. So, they are the departments that must insist that the PSSR has been done, so they will have the tools they need to be safe.