Pre-Startup Safety Review (PSSR)

Definition: A Pre-Startup Safety Review (PSSR) is a formal inspection and verification process completed before a new or modified process facility starts operations. It confirms that construction meets design specifications, safety systems are functional, operating procedures are complete, and personnel are adequately trained to work safely.

What Is a Pre-Startup Safety Review?

A Pre-Startup Safety Review is the final verification step before a process unit or piece of equipment is commissioned for the first time, or restarted after a significant modification. It is not a design review or a risk analysis. It is a physical and documentary check that answers one question: is everything actually ready to operate safely?

The PSSR sits at the intersection of construction completion and live operations. By the time a PSSR takes place, equipment has been installed, piping has been pressure-tested, and instruments have been calibrated. The review confirms that what was designed and approved on paper has been built correctly in the field, and that the human side of operations, procedures, and training, is equally prepared.

When Is a PSSR Required?

Under OSHA Process Safety Management (PSM) standard 29 CFR 1910.119(i), a PSSR is mandatory in two situations:

  • New facilities: Any new process facility that uses highly hazardous chemicals above OSHA threshold quantities requires a PSSR before initial startup.
  • Modified facilities: Any modification that triggers a Management of Change (MOC) review requires a PSSR before the modified equipment or process is restarted. This includes changes to process chemistry, equipment design, operating limits, and safety systems.

Many facilities also apply PSSR requirements beyond the strict OSHA threshold, extending the practice to non-PSM equipment, utilities, and contractor-managed systems. This is considered best practice in high-hazard industries such as oil and gas, chemical processing, pharmaceuticals, and power generation.

A PSSR is also required after extended shutdowns, major repairs, or when equipment failure leads to a significant rebuild. Any time the as-built condition of a system is uncertain, a PSSR is the appropriate verification step before returning to service.

Key PSSR Checklist Elements

A thorough PSSR checks four categories. Missing any one of them leaves a gap that can cause incidents after startup.

1. Equipment and Construction

  • Equipment is installed per approved engineering drawings and specifications.
  • Piping and instrumentation diagrams (P&IDs) reflect the as-built configuration.
  • All construction punch-list items are closed.
  • Pressure vessels, piping, and valves have been inspected and hydrotested where required.
  • Electrical and instrumentation systems are commissioned and verified.

2. Safety and Relief Systems

  • Safety relief valves are installed, set to the correct pressure, and tested.
  • Emergency shutdown systems and interlocks are functional and logic-tested.
  • Fire and gas detection systems are calibrated and alarmed correctly.
  • Ventilation, containment, and drainage systems meet design requirements.
  • Lockout/tagout procedures are in place for all energy isolation points.

3. Operating Procedures

  • Startup, normal operation, shutdown, and emergency procedures are written, reviewed, and approved.
  • Procedures are accessible to operators at the point of use.
  • Safe operating limits (temperature, pressure, flow, composition) are defined in the procedures.

4. Personnel Training

  • All operators and maintenance personnel have completed required training for the new or modified process.
  • Training records are documented and retained.
  • Emergency response roles are assigned and personnel understand their responsibilities.

Who Conducts a PSSR?

A PSSR is a team activity. No single person has the expertise to verify all four checklist categories. A typical PSSR team includes:

Team Member Primary Responsibility in PSSR
Process Engineer Verifies equipment is built to design specifications and P&IDs are accurate
Maintenance Technician Confirms equipment condition, lubrication, alignment, and inspection sign-offs
Safety Officer Reviews safety systems, emergency procedures, PPE requirements, and maintenance safety controls
Operations Supervisor Confirms operators are trained, procedures are available, and the team is ready
Instrumentation Specialist Validates calibration of sensors, alarms, interlocks, and control loops
Environmental Compliance Lead Confirms environmental compliance permits, emissions controls, and spill containment are in place

The team leader is typically the process or project engineer for the facility. They are responsible for tracking all open action items, obtaining sign-offs from each discipline, and authorizing the final startup recommendation.

PSSR vs HAZOP

PSSR and HAZOP (Hazard and Operability Study) are both safety tools used in process industries, but they serve different purposes at different stages of the project lifecycle.

Attribute HAZOP PSSR
Purpose Identify potential hazards and operability problems in the design Verify that hazard controls are correctly installed and ready for startup
Timing During design phase, before construction After construction, immediately before startup
Scope Process deviations, failure scenarios, what-if analysis Physical construction, safety systems, procedures, and training
Output Risk register, action items for design changes and safeguards Signed completion report, open items log, startup authorization
OSHA Requirement Required under PSM for covered processes (as a Process Hazard Analysis) Required under PSM 29 CFR 1910.119(i) for new and modified facilities
Key Question "What could go wrong with this design?" "Is everything actually ready to operate safely?"

In practice, the PSSR team reviews the HAZOP action register as part of its scope, confirming that every safeguard recommended during the HAZOP has been implemented in the field.

How to Document a PSSR

OSHA requires that PSSR results be documented and retained as part of the PSM program. Effective documentation serves two purposes: it provides the audit trail regulators expect, and it creates a baseline record for future modifications and preventive maintenance planning.

A complete PSSR documentation package typically includes:

  • PSSR checklist: A signed checklist covering all four categories (equipment, safety systems, procedures, training), with a pass or fail status for each item.
  • Open items log: A list of any deficiencies found during the review, the required corrective action, the responsible person, and the target completion date. Items may be classified as pre-startup (must be resolved before startup is authorized) or post-startup (can be resolved after startup under a formal tracking system).
  • Sign-off sheet: Signatures from each discipline representative confirming their area of responsibility has been reviewed and accepted.
  • Startup authorization: A final authorization document signed by the facility or project manager confirming that all pre-startup items are closed and the facility is cleared for startup.

Most facilities use a standardized PSSR form tailored to their process types. The form is typically managed within a work management or safety management system to maintain traceability across multiple startup events.

Common PSSR Deficiencies to Watch For

Field experience shows that PSSR teams most often encounter deficiencies in the following areas:

  • P&IDs that do not reflect as-built conditions after field changes during construction
  • Safety relief valves that are installed but not yet set to the correct operating pressure
  • Alarms that are configured in the control system but not validated against field instruments
  • Operating procedures that have been drafted but not reviewed or formally approved
  • Training records that are incomplete for contractors or newly hired operators
  • Lockout/tagout procedures that do not yet cover the new or modified energy isolation points

Each of these is a pre-startup item. None of them should be accepted as post-startup action items, as they represent direct barriers to safe operation from day one.

The Bottom Line

A Pre-Startup Safety Review is not a formality. It is the last line of defense between the end of construction and the start of live operations. When done well, it catches the gaps that design reviews, engineering audits, and construction inspections miss: the relief valve that was ordered but never installed, the procedure that was written for an older configuration, the operator who was trained on a simulator but never reviewed the updated startup sequence.

For facilities subject to OSHA PSM, the PSSR is a legal requirement with a documented record. For all other facilities, it is simply good practice. Either way, the cost of a thorough PSSR is measured in days. The cost of skipping one can be measured in lives, equipment losses, and regulatory consequences that persist for years.

Connecting PSSR findings to your ongoing maintenance program, particularly by feeding confirmed deficiencies into your work order and inspection schedules, ensures that the discipline applied at startup continues through the full operating lifecycle of the asset.

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Frequently Asked Questions

What is a Pre-Startup Safety Review (PSSR)?

A PSSR is a formal inspection completed before a new or modified process facility starts up. It verifies that equipment is installed correctly, safety systems are functional, operating procedures are complete, and personnel are trained. Under OSHA's PSM standard (29 CFR 1910.119), a PSSR is a legal requirement for covered facilities before initial startup or restart after a modification.

When is a PSSR required under OSHA?

OSHA requires a PSSR under 29 CFR 1910.119(i) for two situations: before initial startup of a new PSM-covered facility, and before startup of a modified facility where the change triggered a Management of Change review. Many facilities voluntarily extend PSSR requirements to non-PSM equipment and systems as a best practice.

Who should be on the PSSR team?

A PSSR team typically includes a process engineer, maintenance technician, safety officer, operations supervisor, instrumentation specialist, and an environmental compliance representative. Each discipline is responsible for signing off on their area before startup is authorized. The team size scales with the complexity of the facility or modification being reviewed.

What happens if a PSSR is skipped?

Skipping a required PSSR creates both safety and compliance risk. Undetected installation errors or missing safety devices can cause fires, explosions, or toxic releases. Under OSHA PSM regulations, failure to complete a required PSSR can result in significant citations and financial penalties. Beyond regulatory consequences, the cost of a process safety incident typically far exceeds any time saved by skipping the review.

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