Retail Facility Exemption — When Does It Apply?
1994
The retail exemption under § 1910.119(a)(2)(i) applies only to facilities whose primary purpose is selling the highly hazardous chemical to end users. Facilities that use listed chemicals in their own production processes — even if they also sell them — are not exempt and are fully covered by PSM.
Laboratory Exemption — Scope and Limits
1994
The laboratory exemption (§ 1910.119(a)(2)(iii)) applies only to laboratories under the direct supervision of a technically qualified individual conducting research or development activities. It does not apply to production-scale operations located within a building called a "laboratory," nor to pilot plants handling quantities at or above TQ thresholds.
Connected Vessels — Single Process TQ Calculation
1994
Vessels containing the same highly hazardous chemical that are interconnected by process piping and operated as a single process unit must have their quantities aggregated when calculating threshold quantity. They constitute one process for PSM purposes, regardless of physical distance, as long as they share process connectivity.
Flammable Liquids — The 10,000 lb Catch-All Coverage Rule
1992
A flammable liquid or gas not specifically listed in Appendix A is still subject to PSM if: (1) it has an atmospheric boiling point below 68°F (20°C), OR is stored above its boiling point, AND (2) quantities on-site reach 10,000 pounds (4,535 kg). OSHA has confirmed this catch-all applies even to common materials like propane, ethylene, and LNG not separately listed.
Normally Unoccupied Remote Facilities
1993
§ 1910.119(a)(2)(ii) exempts facilities where the only on-site employee is the attendant and the facility is "normally unoccupied." OSHA has clarified this is a narrow exemption — a facility where workers regularly perform MI tasks, MOC work, or process monitoring does not qualify. The exemption requires truly minimal human presence in normal operations.
Replacement in Kind — The Definitive Definition
1994
"Replacement in kind" means a replacement that satisfies the design specifications of the original component — same material, same size, same operating parameters, same functionality. Any deviation from the documented specifications — including a different alloy, a higher-rated component used in a different service, or a change in control logic — requires MOC, regardless of how minor it may appear to the installer.
Temporary Changes — Time Limits Are Mandatory
1995
OSHA requires that temporary changes authorized under MOC have a defined expiration date. A change that is indefinitely renewed as "temporary" is not a temporary change — it is a permanent change that requires full MOC documentation, including updated PSI, PHA review, and operating procedure updates. Chains of temporary extensions are a common PSM citation.
Instrumentation Changes and Set Point Adjustments
1995
Changing the range, calibration range, material of construction, or alarm/trip setpoints of instrumentation beyond the range documented in the original design specifications triggers MOC. Operating within already-documented limits is not a change. However, permanently shifting setpoints — especially safety-critical ones — to values outside the original basis of design requires MOC and PHA review of the impact.
Organizational Changes and Staffing Reductions
1995
OSHA has stated that a reduction in staffing or reorganization of personnel that affects process safety — such as eliminating a dedicated process safety role, reducing operator-to-unit ratios, or changing emergency response team composition — may trigger MOC review. Purely administrative organizational changes with no process safety implications do not. Each situation must be evaluated on its own merits.
PHA Team Composition Requirements
1993
Per § 1910.119(e)(4), the PHA team must include: (1) at least one person with expertise in engineering and process operations, (2) at least one person knowledgeable in the specific PHA methodology being used, and (3) at least one employee who currently operates the process. OSHA has confirmed that a team of engineers with no active operator is non-compliant, regardless of their collective experience.
Revalidation Clock — Completion Date, Not Start Date
1994
OSHA has clarified that the 5-year revalidation clock required by § 1910.119(e)(6) runs from the date the PHA was completed, not the date it was initiated, scheduled, or approved by management. The PHA is "complete" when the team's analysis work is finished and documented. Delays in management review or recommendation approval do not extend the deadline.
PHA Methodology — OSHA Does Not Mandate HAZOP
1993
OSHA does not require HAZOP specifically. § 1910.119(e)(2) lists several acceptable methodologies including What-If, Checklist, What-If/Checklist, HAZOP, FMEA, Fault Tree Analysis, and combinations. The employer must select a methodology appropriate to the complexity of the process. OSHA may question methodology selection if it appears inadequate for the process hazards identified — but adequacy is measured against hazard complexity, not methodology type alone.
PHA Recommendations — Timely Resolution Required
1994
§ 1910.119(e)(5) requires employers to establish a system to address PHA team findings and recommendations in a timely manner. OSHA has interpreted this to mean: document each recommendation, assign a responsible party, track completion, and notify workers of relevant results. Recommendations that sit unresolved for years — particularly those addressing serious hazards — are frequently cited as PSM violations independent of the PHA finding itself.
PHA Must Address Prior Incidents and Near-Misses
1993
§ 1910.119(e)(3)(v) explicitly requires that PHAs address the engineering and administrative controls applicable to the hazards identified, including the consequences of failure. OSHA has clarified that the PHA team must review and address prior incidents and near-misses from the process. Failing to reference a prior incident that is directly relevant to a identified hazard scenario is a basis for citation.
P&IDs Must Reflect Current Installed Conditions
1993
§ 1910.119(d)(3)(ii) requires P&IDs as part of PSI. OSHA has clarified that P&IDs must reflect the current, actual installed conditions of the process — not the original design or a last-known state. The age of a drawing alone does not determine compliance; what matters is accuracy. Undocumented field modifications that appear on plant walkdown but not on the P&ID are a PSI deficiency and a common PHA team complaint.
Consequence Analysis in PSI — No Specific Tool Required
1994
OSHA does not mandate a specific consequence modeling tool or methodology for PSI. What is required is that the employer has information on the consequences of deviation sufficient to support the PHA. OSHA has stated that simplified consequence estimates may be acceptable for lower-hazard processes, while complex, high-inventory processes warrant more rigorous analysis. The adequacy standard is whether the information supports identification and analysis of process hazards.
Relief System Design Documentation in PSI
1994
§ 1910.119(d)(3)(vi) requires relief system design and design basis as part of PSI. OSHA has clarified that this means the employer must be able to document the design basis for each relief device — the scenarios it was designed to protect against, the calculated required relieving capacity, and the selected device's rated capacity. A relief valve tag with a set pressure alone does not satisfy this requirement.
Host Employer Cannot Delegate PSM Obligations to Contractors
1993
OSHA has firmly stated that the host employer's obligations under § 1910.119(h) cannot be satisfied simply by requiring contractors to maintain their own PSM programs. The host employer remains responsible for ensuring contractors receive required process hazard information, that their safety programs are evaluated, and that contractor employees performing covered work are trained on process-specific hazards. Relying solely on a contractor's own documentation is a PSM violation for the host.
Evaluating Contractor Safety Performance Before Award
1993
§ 1910.119(h)(2)(i) requires the employer to obtain and evaluate contractor safety performance information before selecting a contractor for covered work. OSHA has clarified that evaluating only injury and illness rates is insufficient if process-specific safety capability is not also assessed. The documentation of this evaluation must be retained — a verbal check or undocumented call to a reference is not adequate evidence of compliance on inspection.
Periodic Evaluation of Long-Term On-Site Contractors
1994
§ 1910.119(h)(4) requires employers to periodically evaluate contractor performance in fulfilling PSM obligations. For contractors with long-term or resident site presence, OSHA has stated that "periodically" means at regular, documented intervals — not only at contract renewal. A contractor whose process safety performance has degraded during a long-term engagement must be re-evaluated and deficiencies corrected before they can continue covered work.
MI Inspection Frequency — RAGAGEP Is the Standard
1995
OSHA has confirmed that inspection and testing frequencies for process equipment must follow recognized and generally accepted good engineering practice (RAGAGEP) — which includes API, ASME, NFPA, and other recognized standards. Employers may document a technical basis for intervals that differ from RAGAGEP defaults, but deviations must be supported by engineering analysis. Simply following manufacturer recommendations without considering applicable RAGAGEP is not sufficient if the two conflict.
Equipment Deficiencies — Corrective Action Before Use
1995
§ 1910.119(j)(5) requires that deficiencies in equipment that are outside acceptable limits be corrected before further use, or in a safe and timely manner when the deficiency does not create an immediate hazard. OSHA has cited employers for documenting a deficiency during inspection and then continuing to operate without correction or a documented engineering justification for safe continued operation. The decision to continue operating must be formally documented and technically defensible.
Quality Assurance — Materials and Fabrication Verification
1994
§ 1910.119(j)(6) requires quality assurance for new and replacement parts used in PSM-covered equipment. OSHA has clarified that this means verifying that materials meet the specified requirements before installation — not just after. Simply receiving a "certificate of compliance" from a supplier without a verification process does not satisfy QA requirements. The employer must have a documented program for materials verification, particularly for safety-critical components like pressure vessels and piping.
Refresher Training — 3-Year Minimum, Not Maximum
1997
§ 1910.119(g)(2) requires refresher training at least every three years, or more frequently if employees or the employer determine it is necessary. OSHA has stated this is a minimum interval, not a safe harbor. An employer who refreshes every 3 years but has not consulted with employees about whether a shorter interval is warranted — particularly following incidents, near-misses, or significant procedural changes — may still be cited if training adequacy cannot be demonstrated.
Initial Training for Pre-Standard Employees
1992
Employees already operating covered processes when PSM took effect in 1992 were still required to demonstrate initial training competency — either through documented prior training or by completing new training under the PSM standard. Employees who had operated a process for many years but had no documented training on safety and health hazards, emergency operations, or safe work practices were not automatically compliant. Documentation of competency is required regardless of experience.
Training Certification — Understanding Must Be Verified
1993
§ 1910.119(g)(3) requires employers to certify that employees have understood training. OSHA has clarified that a signature on an attendance sheet alone does not constitute certification of understanding. The employer must use some means to verify comprehension — a written test, oral examination, skills demonstration, or other method. The certification record must reflect the date, the means of verifying understanding, and the trainer's identity.
When PSSR Is Required — New and Modified Processes
1994
§ 1910.119(i) requires a pre-startup safety review for new facilities and for modified facilities where the modification is significant enough to require a change in the process safety information. OSHA has clarified that the PSSR trigger is any modification that goes through MOC. A modification that is truly replacement in kind — not requiring MOC — also does not require a separate PSSR, though the relevant inspection and testing requirements under MI still apply.
Who Must Conduct the PSSR?
1993
OSHA has clarified that § 1910.119(i) does not require a specific team composition for PSSR — unlike PHA, it does not prescribe an operator-inclusive team. What it does require is that the PSSR confirms all four required items: (1) construction and equipment is in accordance with design specs, (2) safety, operating, maintenance, and emergency procedures are in place, (3) PHA recommendations are addressed, and (4) training of employees is complete. The PSSR must be conducted by personnel competent to evaluate each of these areas.
Hot Work Permit — Scope Is Broader Than Welding
1993
§ 1910.119(k) requires a hot work permit for any hot work — defined as work involving ignition sources — in or near covered processes. OSHA has clarified that this is not limited to welding and cutting. Grinding, abrasive blasting, spark-producing power tools, and other ignition-source activities within the applicable area all require permits. The permit must document authorization, the equipment or process affected, and fire prevention and protection measures.
Compliance Audit Team — Who Qualifies?
1995
§ 1910.119(o) requires compliance audits at least every 3 years, conducted by at least one person knowledgeable in the process. OSHA has confirmed that external consultants can conduct or participate in compliance audits, and their use may be beneficial for independence. However, at least one team member must be knowledgeable in the PSM standard as it applies to the specific process being audited — not just generically familiar with safety auditing. The audit must cover all applicable elements of § 1910.119.