What is a Pre-Startup Safety Review (PSSR)? Requirements and Best Practices
What is a Pre-Startup Safety Review (PSSR)? Requirements and Best Practices
Author: Fidelis Associates | Published: 2026-02-26 | Last Updated: 2026-02-26
Meta Description: A Pre-Startup Safety Review (PSSR) is a systematic review required by OSHA PSM before introducing hazardous materials into new or modified facilities. Learn PSSR requirements, process, and best practices.
Definition
A Pre-Startup Safety Review (PSSR) is a systematic, documented review conducted before introducing highly hazardous chemicals or energy into a new or modified facility. Required by OSHA under 29 CFR 1910.119(i), PSSR confirms that construction is complete, equipment is installed correctly, safety systems are operational, procedures are in place, training is adequate, and the facility is ready for safe operation.
PSSR is one of the 14 elements of Process Safety Management (PSM) and serves as the final verification gate before a process goes live. It applies across petroleum refineries, petrochemical plants, chemical manufacturing facilities, LNG terminals, and hydrogen production facilities. It is not a formality — it is the last structured opportunity to identify and resolve safety gaps before hazardous materials are present.
Table of Contents
- When Is a Pre-Startup Safety Review Required?
- What PSSR Must Confirm
- PSSR vs. Other Safety Reviews
- What Are the Most Common PSSR Failures?
- Best Practices for Effective PSSRs
- PSSR in Multi-Party Environments
When Is a Pre-Startup Safety Review Required?
OSHA requires a PSSR for:
- New facilities before initial startup with highly hazardous chemicals
- Modified facilities when changes are significant enough to require a change in process safety information
- New processes or changes to existing processes that could affect the process safety of the facility
The trigger is typically connected to the Management of Change (MOC) process. When an MOC identifies that a change affects process safety information, operating procedures, or the physical process, a PSSR should be part of the pre-startup verification.
Common PSSR Triggers
| Trigger | PSSR Required? | | -------------------------------------------- | ------------------------------------------------------- | | New facility construction | Yes | | Equipment replacement (like for like) | Typically no, unless process safety information changes | | Equipment modification | Yes, if it changes process safety information | | Process chemistry change | Yes | | New instrumentation affecting safety systems | Yes | | Operating procedure change only | Generally no, but must be evaluated through MOC | | Turnaround with significant modifications | Yes, for modified systems |
What PSSR Must Confirm
Under OSHA 1910.119(i), PSSR must confirm that:
1. Construction and Equipment
- Construction and equipment are in accordance with design specifications
- Physical installation matches P&IDs and engineering drawings
- Materials of construction meet specifications
- Equipment is properly tagged and identified
2. Safety, Operating, Maintenance, and Emergency Procedures
- All required procedures are in place, reviewed, and accessible
- Procedures are specific to the process being started
- Emergency procedures address credible scenarios
- Maintenance procedures cover critical equipment
3. Process Hazard Analysis Recommendations
- All PHA recommendations relevant to the new or modified process have been resolved or appropriately addressed
- Any open PHA items have been evaluated and documented
- Temporary risk controls are in place where needed
4. Training
- All operators, maintenance personnel, and contractors have been trained on new or modified procedures
- Training records are complete and documented
- Personnel demonstrate competency in new operating scenarios
5. Modified Facilities — Additional Requirements
For modified facilities, PSSR must additionally confirm that the MOC requirements under 1910.119(l) have been satisfied before startup.
6. Control System Cybersecurity Verification
Modern process facilities rely on networked control systems that introduce cybersecurity risks directly relevant to process safety. PSSR should verify that control system security configurations are in place before startup:
- DCS and SIS network segmentation verified — the process control network and safety instrumented system are isolated from business networks and from each other in accordance with ISA/IEC 62443 zone and conduit models
- Default credentials changed on all control system components, including controllers, engineering workstations, HMI terminals, network switches, and embedded devices
- Remote access configurations reviewed and secured — VPN connections, vendor remote support links, and any external access paths have been evaluated, authorized, and documented
- Firmware versions verified against known vulnerability databases — controller and device firmware checked against ICS-CERT advisories and vendor security bulletins
- Backup and recovery procedures tested for control system configurations, logic programs, and historian data — with verified ability to restore from backup in the event of a cyber incident or system failure
Control system cybersecurity is increasingly recognized as a process safety issue. A compromised DCS or SIS can directly cause the types of catastrophic events that PSM is designed to prevent.
PSSR vs. Other Safety Reviews
| Review | Purpose | Timing | Scope | | -------------------- | -------------------------------------------------- | --------------------------- | --------------------------------------- | | PSSR | Confirm readiness to introduce hazardous materials | Before startup | Construction, procedures, training, PHA | | PHA/HAZOP | Identify process hazards and evaluate safeguards | Design/revalidation | Process-level hazard identification | | ORR | Assess overall operational readiness | Before/during commissioning | Comprehensive organizational readiness | | MoC Review | Evaluate impact of changes | Before implementing changes | Change-specific safety impact | | Compliance Audit | Verify PSM program compliance | Every 3 years | All 14 PSM elements |
PSSR is narrower than an Operational Readiness Review (ORR). An ORR evaluates the entire organization's readiness to operate, while PSSR specifically confirms that the regulatory requirements for safe introduction of hazardous chemicals have been met.
What Are the Most Common PSSR Failures?
Based on experience facilitating PSSRs across refineries, chemical plants, hydrogen facilities, and greenfield startups:
1. Treated as a Checkbox Exercise
The most common failure. Teams rush through PSSR as paperwork rather than substantive safety verification. Findings are either not generated or are immediately closed without real resolution.
2. Incomplete P&ID Verification
As-built conditions don't match design drawings. Field modifications during construction were not captured in process safety information. Relief valve settings, instrument ranges, or piping configurations differ from what was engineered.
3. Procedures Written but Not Validated
Operating procedures exist on paper but haven't been walked through with the operators who will use them. Procedures written in the engineering office may not reflect field reality, equipment layout, or operator workflow.
4. Training Conducted but Not Verified
Training records show completion, but personnel cannot demonstrate competency in critical operations. Training was delivered as classroom instruction without hands-on verification.
5. Open PHA Items Not Addressed
PHA recommendations remain open at the time of PSSR. Without a clear process for tracking, prioritizing, and resolving PHA findings before startup, critical safety gaps can persist into live operations.
6. Ownership Confusion in Multi-Party Projects
In projects with separate EPC, owner, and operator entities, no one clearly owns the PSSR process. Each party assumes the other is responsible for specific aspects, resulting in gaps that no one catches until startup.
Best Practices for Effective PSSRs
Start Early
PSSR preparation should begin during detailed engineering, not at the end of construction. Identify PSSR scope, participants, and criteria early so the team knows what must be ready before the review.
Use a Structured Checklist
Develop a PSSR checklist specific to the process and facility. Generic checklists miss process-specific items. The checklist should cover all OSHA requirements plus any company-specific or site-specific standards.
Verify in the Field
PSSR requires physical verification, not just document review. Walk down equipment, verify as-built conditions against drawings, test safety systems, and confirm that control room interfaces match the process.
Track Findings to Closure
Every PSSR finding must have an owner, a due date, and a closure verification process. Critical findings must be resolved before hazardous materials are introduced. Non-critical findings can be tracked for post-startup resolution if properly risk-assessed.
Include the Right People
PSSR participants should include operations, maintenance, engineering, safety, and management representatives. External facilitation can bring objectivity and experience from other facilities and industries.
Document Everything
PSSR documentation must demonstrate compliance to regulators, internal auditors, and future teams. Records should include the scope, participants, findings, corrective actions, closure evidence, and final authorization.
PSSR in Multi-Party Environments
Hydrogen production facilities, LNG terminals, greenfield petrochemical plants, and major capital projects often involve multiple parties — an EPC contractor, the asset owner, and the future operator. In these environments, PSSR ownership can become ambiguous.
Key Questions to Resolve Before PSSR
- Who authorizes startup? The owner, the operator, or the EPC?
- Who owns procedures? Were they written by engineering or by operations?
- Who conducts field verification? EPC QA/QC, owner's engineering, or operations?
- Who facilitates the PSSR? Internal team or independent third party?
- How are vendor systems handled? Package units with vendor-controlled startup sequences?
Fidelis Associates has facilitated PSSRs in multi-party environments including greenfield hydrogen facilities, used oil re-refineries, and major capital projects for Fortune 500 operators. Our approach clarifies ownership, drives accountability, and ensures findings are tracked to genuine resolution.
Learn about FidelisForce PSSR Facilitation →
Related Resources
- What is Process Safety Management? A Complete Guide — PSSR is one of the 14 PSM elements. Understand the full framework.
- Hydrogen Properties That Make It Different: A Safety Guide — Hydrogen facilities require specialized PSSR considerations.
How Fidelis Can Help
Free Self-Assessment (FidelisCheck)
Benchmark your operational readiness and PSSR preparedness with a free online assessment.
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Expert-Led Assessment (FidelisGap)
For a comprehensive evaluation of your PSSR process, procedures, and readiness posture, FidelisGap brings experienced professionals into your facility.
PSSR Facilitation (FidelisForce)
Fidelis provides experienced PSSR facilitators who have led reviews across refineries, chemical plants, hydrogen facilities, and greenfield startups.
Frequently Asked Questions
How long does a PSSR take? Duration depends on the scope and complexity. A single-system PSSR for a modification at an existing refinery can be completed in a day. A full-facility PSSR for a greenfield hydrogen production facility or new petrochemical plant may take weeks, with multiple rounds of findings and closures.
Can PSSR be done remotely? No. PSSR requires physical field verification. Document reviews can be prepared remotely, but the review itself must include on-site walkdowns and equipment verification.
What happens if PSSR findings are not resolved before startup? OSHA expects that all PSSR requirements are met before highly hazardous chemicals are introduced. Starting up with unresolved PSSR findings is a compliance risk and a safety risk. If business conditions require startup with open items, those items must be formally risk-assessed and temporary controls documented.
Fidelis Associates provides PSSR facilitation and operational readiness services through FidelisForce and FidelisCore. Our team has facilitated PSSRs across hydrogen production facilities, environmental services operations, and major refining operations.
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