PSM Job Posting Terms
Decoded in Plain English

A structured, systematic examination of a process or operation in which a multidisciplinary team uses guide words (MORE, LESS, NO, REVERSE, OTHER THAN, etc.) to identify deviations from design intent and evaluate the potential hazardous consequences of those deviations.

A brainstorming-based PHA technique where the team asks "What if...?" questions about the process to identify hazardous scenarios. Often combined with a checklist to ensure systematic coverage. Less rigorous than HAZOP but faster and useful for simpler processes.

A systematic method for identifying all possible failures in a system and their effects on overall system function. Particularly useful for mechanical integrity reviews, equipment design, and evaluating instrumented safety systems. Each failure mode is evaluated for likelihood, detectability, and severity.

A risk visualization tool that maps threats (causes) on the left, a top event (the hazard) at the center, and consequences on the right — resembling a bow tie. Barriers (preventive on the left, mitigating on the right) are placed on the "legs" to show how risks are controlled. Increasingly used alongside or instead of fault trees for communication to leadership.

Fault Tree Analysis (FTA) is a deductive, top-down method that uses Boolean logic to model how combinations of failures lead to a specific undesired event. Event Tree Analysis (ETA) is an inductive, forward-looking method that models the possible outcomes following an initiating event based on the success or failure of safeguards.

Under 29 CFR 1910.119(e)(6), process hazard analyses must be redone or updated at least every 5 years. A revalidation reviews the prior PHA, incorporates changes made since the last study, evaluates new information, and documents that all prior recommendations were addressed.

Risk evaluation using descriptive categories rather than numbers — likelihood and consequence rated as Low/Medium/High or similar scales, combined in a risk matrix to produce a risk ranking. The output is a relative ranking that guides prioritization of risk reduction measures. Most PHAs under 29 CFR 1910.119 are qualitative.

Risk evaluation that assigns actual numeric values to likelihood (event frequencies in events/year) and consequence (fatality probability, injury zones, toxic exposure distances). Outputs include individual risk (probability of fatality per year at a location), societal risk (F-N curves), and risk contour maps. Tools include PHAST, SAFETI, RISKAT, and custom models.

A simplified quantitative risk assessment method that evaluates whether the independent protection layers (IPLs) for a scenario are sufficient to reduce risk to a tolerable level. Each IPL is assigned a probability of failure on demand (PFD); the combined PFD determines whether the remaining risk is acceptable. LOPA is the primary tool used to determine SIL targets for safety instrumented functions.

Computational modeling of the physical effects of accidental releases — toxic cloud dispersion, vapor cloud explosion overpressure, flash fire extent, pool fire radiation, and BLEVE fireballs. Software tools include PHAST (DNV), SAFETI (DNV), ALOHA (EPA/NOAA), CAMEO, and EFFECTS (TNO).

F-N (frequency-number) curves plot the cumulative frequency of events against the number of fatalities, used to evaluate societal risk. Tolerable risk criteria define the upper limits of acceptable individual and societal risk. Common benchmarks: individual risk < 1×10⁻⁵/year for workers, < 1×10⁻⁶/year for the public.

A measure of the risk reduction capability of a Safety Instrumented Function (SIF). SIL 1 provides risk reduction of 10–100x (PFD 0.1–0.01), SIL 2 provides 100–1,000x, SIL 3 provides 1,000–10,000x. SIL targets are determined by LOPA or risk graphs. The IEC 61511 standard governs SIL assignment, verification, and lifecycle management in the process industry.

An instrumented system designed to bring a process to a safe state when predetermined conditions are violated. Consists of sensors (initiators), a logic solver (safety PLC), and final elements (valves, trips). SIS must be independent of the basic process control system. Governed by IEC 61511 in the process industry.

The engineering of pressure safety valve systems, rupture disks, and emergency venting to protect process equipment from overpressure scenarios. Includes basis of design, case development (fire case, blocked outlet, utility failure), sizing per API 520/521/526, and relief system documentation per PSM Process Safety Information requirements.

A design philosophy that seeks to eliminate or reduce hazards at the source rather than controlling them with added-on safeguards. ISD strategies: Substitute (use a less hazardous material), Minimize (reduce inventory), Moderate (use less hazardous conditions), Simplify (reduce complexity that leads to error). ISD is increasingly required at the PHA stage and during new project design.

The Management of Change element (1910.119(l)) requires a formal process to evaluate and authorize changes to process chemicals, technology, equipment, procedures, and facilities before implementation. "MOC ownership" means responsibility for the program — maintaining the procedure, training approvers, reviewing MOC quality, and ensuring action items are closed before startup.

The Pre-Startup Safety Review (1910.119(i)) is a systematic review required before a new or modified process is started up to confirm that PSM requirements are satisfied. PSSR leadership means planning the review, assembling the cross-functional team, managing the checklist, and ensuring all action items are resolved before startup authorization.

Building or evaluating the written programs, procedures, and systems required by 29 CFR 1910.119 across all 14 elements. A gap assessment benchmarks current practice against regulatory requirements, identifies deficiencies, and produces a corrective action plan. Common in acquisition due diligence, new facility startups, and enforcement settlement situations.

Systematic investigation of process safety incidents, near-misses, and process deviations to identify direct causes, contributing factors, and root causes — and develop recommendations to prevent recurrence. Common methodologies: SCAT, TAPROOT, Cause Mapping, Why-Tree, Fishbone/Ishikawa. PSM requires investigation for any incident "which resulted in, or could reasonably have resulted in, a catastrophic release."

29 CFR 1910.119(o) requires facilities to certify compliance with PSM requirements through at least one person knowledgeable in the process and at least one audit at least every 3 years. A PSM compliance audit systematically evaluates all 14 elements against regulatory requirements and facility procedures, producing findings and recommendations that must be documented and resolved.

A protection layer that is independent, auditable, and capable of preventing the scenario from progressing to a consequence without relying on the same equipment or people involved in the initiating event. IPL credit is granted in LOPA to reduce the unmitigated event frequency. Basic process control systems, alarms, and procedures may be IPLs under specific conditions; SIS functions meeting SIL criteria are IPLs.

The probability that a protection layer (typically a safety instrumented function) will fail to respond correctly when demanded. PFD is the primary metric used in SIL verification. A SIL 1 SIF has a PFD of 0.01–0.1 (1–10% failure probability), SIL 2 is 0.001–0.01, SIL 3 is 0.0001–0.001. PFD is calculated from component failure rates and proof test intervals.

A tool for qualitatively evaluating risk by combining likelihood (frequency) and severity (consequence) ratings on a matrix. The resulting risk level (e.g., Low, Medium, High, Intolerable) guides prioritization of risk reduction actions. Risk matrices are used in PHAs, incident investigations, MOC reviews, and management of operational risk.

The process of evaluating whether the safeguards identified in a PHA or LOPA study are adequate to reduce risk to a tolerable level. Requires understanding of what constitutes an independent, auditable, and reliable protection layer — and when additional safeguards or risk reduction is needed.

A board-certified safety credential issued by the Board of Certified Safety Professionals (BCSP). Requires at least a bachelor's degree, professional safety experience, and passing the CSP examination. The CSP is one of the most widely recognized credentials in occupational safety and health, including process safety roles.

A credential offered by CCPS (Center for Chemical Process Safety, an AIChE affiliate) recognizing individuals who have demonstrated competency in process safety management. Requires documented process safety experience, continuing education, and endorsement. More specifically focused on PSM than the CSP.

A Process Safety Engineer typically holds an engineering degree and performs technical analysis — PHA facilitation, LOPA, consequence modeling, SIL verification, relief system review. A Process Safety Coordinator manages the administrative elements of a PSM program — tracking PHA schedules, audit findings, training records, MOC documentation — and may not have a technical engineering background.

At PSM-covered facilities, the Plant Manager or Site Director holds ultimate accountability for PSM compliance under 1910.119. OSHA expects senior site leadership to be knowledgeable in PSM requirements and to certify the compliance audit. A Plant Manager at a PSM facility who has no PSM background is an audit finding waiting to happen.

The person responsible for planning and leading a Process Hazard Analysis study — selecting the methodology, organizing the team, managing the study sessions, ensuring completeness, documenting findings, and producing the final report with recommendations. Effective facilitators are skilled at managing group dynamics and technical discussions simultaneously.

The Center for Chemical Process Safety (CCPS) framework for process safety management, organized around 20 elements in four pillars: Commit to Process Safety, Understand Hazards & Risk, Manage Risk, and Learn from Experience. RBPS is not a regulatory requirement — it is a voluntary best-practice framework that goes beyond OSHA PSM's 14 elements.