A PSSR, or Pre-Startup Safety Review, is a formal safety check that must be completed before a new or modified industrial process begins operating. It’s required by OSHA under its Process Safety Management (PSM) standard, specifically section 1910.119(i), and it applies to facilities that handle highly hazardous chemicals. The core idea is straightforward: before you introduce dangerous materials into equipment, a qualified team verifies that everything has been built correctly, procedures are in place, and workers have been trained.
Why a PSSR Exists
Industrial facilities that work with highly hazardous chemicals face serious risks during startup. Equipment may have been installed incorrectly, safety interlocks might not be wired properly, or operators may not yet understand the new process. A PSSR is the final checkpoint that catches these gaps before chemicals start flowing. It sits within OSHA’s broader Process Safety Management program, which covers everything from hazard analysis to emergency planning at covered facilities.
When a PSSR Is Required
OSHA mandates a PSSR in two situations. The first is when a facility builds an entirely new process that falls under the PSM standard. The second is when an existing process undergoes a modification significant enough to change its process safety information, which includes details like chemical inventories, equipment specifications, and operating limits.
In practice, facilities also conduct PSSRs when restarting a covered process after a prolonged shutdown, after renovating spaces, or after installing new equipment that introduces a potential hazard. These reviews often tie directly into a facility’s Management of Change (MOC) program. When someone proposes a change to equipment or procedures, the MOC process determines whether the change is significant enough to trigger a PSSR before the modified system goes live.
What the Review Must Confirm
OSHA’s regulation lays out four specific things a PSSR must verify before highly hazardous chemicals are introduced to the process:
- Construction matches design specifications. All equipment, piping, and facility construction has been installed the way it was engineered. This catches misalignments between what was designed on paper and what was actually built.
- Procedures are in place and adequate. Safety procedures, operating procedures, maintenance procedures, and emergency procedures all need to exist in written form and be appropriate for the process.
- Hazard analysis is resolved. For new facilities, a Process Hazard Analysis (PHA) must have been completed and its recommendations either resolved or implemented. For modified facilities, the requirements of the Management of Change process must be satisfied instead.
- Employee training is complete. Every person involved in operating the process must have finished their training before startup, not during or after.
These four items are the regulatory minimum. Many facilities expand their PSSR checklists to also confirm that process safety documentation is up to date and on file, that safety interlocks function correctly, and that personnel safeguards are in place.
How the Process Works
A PSSR follows a structured workflow. It begins when someone identifies that a review is needed, either because a new facility is being commissioned or because a change has triggered the requirement through the MOC process. For new facilities, the review is typically scheduled after the Process Hazard Analysis report has been issued and its action items addressed. For modifications to existing processes, the person who originated the change request is usually responsible for scheduling the PSSR.
Next, a review team is assembled. The team is selected based on knowledge of and responsibility for the process in question, and at least one member must be experienced in operating it. For a brand-new facility, the team is larger and typically includes representatives from design and construction, engineering, operations management, safety, equipment operators, and environmental health and safety. For an existing process undergoing modification, the team can be smaller: often the MOC originator, equipment operators, and the process safety program manager.
The team then conducts the review itself, walking through the checklist items and documenting any deficiencies, open questions, or action items. This is not a rubber stamp. If the team finds problems, those problems must be fixed before the process starts up. Issues that affect safe operation, like malfunctioning safety interlocks or missing personnel safeguards, cannot be deferred. They have to be corrected first.
Once all deficiencies are remedied and action items are closed, the process safety program manager formally closes the PSSR and communicates the closure to team members. Only then can the process begin operating.
Who Is Responsible
OSHA places the obligation squarely on the employer. It is the employer’s responsibility to perform the PSSR and ensure that all four confirmation items are satisfied before startup. In practice, a process safety program manager or equivalent role typically coordinates the effort, but the review itself is a team activity. No single person signs off alone. The intent is that people with different areas of expertise, from operations to engineering to safety, all evaluate readiness from their respective angles.
For facilities covered by the PSM standard, skipping or inadequately performing a PSSR is a compliance violation that OSHA can cite during an inspection. More importantly, it removes the last safeguard between a flawed setup and a potentially catastrophic startup.