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    PHAProcess Hazard Analysis

    Definition

    Process Hazard Analysis — a structured team examination of a process's hazards, possible consequences and safeguards, repeated on a fixed cycle.

    Editorial definition: The QHSE Standard, updated 3 October 2026 · https://qhsetech.com/glossary/pha

    Scope: The chosen technique and required review cycle depend on the applicable process-safety framework.

    Sources checked: . Examples are editorial illustrations.

    What OSHA and the EPA say about a process hazard analysis

    In 29 CFR 1910.119(e), OSHA requires an initial process hazard analysis for covered processes. It must suit the complexity of the process and must identify, evaluate and control the hazards. The employer determines and documents a priority order for doing the analyses, with a rationale that includes the extent of the hazards, the number of employees potentially affected, the age of the process and its operating history. The analysis uses one or more of the listed methodologies and must address the hazards, previous incidents with catastrophic potential, engineering and administrative controls and their interrelationships, the consequences of failure of those controls, facility siting, human factors and a qualitative evaluation of the possible effects of control failure on employees. Written process safety information, including piping and instrument diagrams and safety systems, has to be compiled before the analysis.

    A team does the work. Findings are addressed promptly, recommendations are resolved in a timely way and the resolution is documented. The gap between the initial analysis and each later update and revalidation may not exceed five years, and the analyses with their updates are kept for the life of the process. Appendix C says a PHA looks at the possible causes and consequences of fires, explosions, major spills and toxic or flammable releases, and concentrates on equipment, instrumentation, utilities, routine and nonroutine human actions and external factors. It says every methodology has limitations, that the team leader should be knowledgeable and impartial, and that a screening or preliminary hazard analysis can help to prioritise. It adds that a team can range from two people to many with varied backgrounds, that some members may join for only part of the study and that at least one must be familiar with the process, and that assumptions made in the study need to be documented and kept for a future analysis.

    EPA's chemical accident prevention guidance has a matching analysis requirement and says that for a process also covered by OSHA's rule, an update, or an initial analysis done after 26 May 1997, has to consider offsite impacts on the public and the environment. This is general information, not legal advice, and other regimes differ.

    Sources opened :

    What a PHA record holds in software

    • The process covered, its boundary, and the process safety information used with its revision dates.
    • The priority order for the analyses and the rationale recorded for it.
    • The methodology chosen and the reason it suits this process, including any mix of methods.
    • The team, its leader, each member's expertise and who has experience of the process.
    • Findings for each element the standard lists, with the safeguards and recommendations.
    • For each recommendation the owner, due date, resolution and completion evidence.
    • Assumptions, the date of the analysis and the dates of updates and revalidations.

    PHA, HAZOP, hazard analysis and preliminary hazard analysis

    A process hazard analysis is the requirement and the overall study, and HAZOP, what-if, FMEA and the others are techniques for carrying it out. PHA is also used for a preliminary or screening analysis, which Appendix C describes as a way to set priorities among processes and which does not replace the full study. A job hazard analysis and a risk assessment of a task are separate exercises with different subjects.

    A hypothetical example: prioritising and revalidating analyses

    The site below is invented and describes no real company. A site has four covered processes and sets a priority order using the extent of the hazards, the number of employees affected, the age of each process and its operating history, and records the rationale. The oldest process with the largest inventory goes first. The team chooses a checklist for a standard utility unit and a HAZOP for the main process, as Appendix C describes as possible, and notes why in the record. The record also shows that the team met the standard's mix of expertise.

    Findings are logged with an owner for each. Two are closed with documented resolutions. A third is not accepted, and the record states the reasoning with the approver's name. Four years after the study the system raises the revalidation task. The team reviews the changes since the study, finds one modification not yet reflected, updates the analysis and sets the next date. Earlier versions are kept, as required for the life of the process.

    Common misunderstandings about PHA

    • A PHA is not one technique. OSHA lists several, and one process can use different methods for different parts.
    • A single meeting does not complete it. Written process safety information must exist first, and findings have to be resolved and the resolutions documented.
    • Five years is a maximum gap for the update and revalidation, not a schedule that excludes earlier review after change.
    • Completing the report is not the end. The standard asks for resolution of recommendations, so open findings keep the analysis incomplete.
    • A PHA is kept per process, not per site. The retention duty applies to each covered process.
    • PHA can mean a preliminary hazard analysis. Appendix C uses a preliminary or gross analysis to set priorities among processes, which is a screening step and not the full study.

    How PHA relates to other glossary terms

    The PHA is one element of process safety management and draws on several techniques.

    • Process safety management: the OSHA standard in which the process hazard analysis is one element.
    • HAZOP: one of the listed methodologies, often used for the overall process.
    • What-if analysis: a lighter listed methodology suited to simpler processes.
    • Management of change: records modifications that should be reflected in updates and revalidations.

    Records and evidence that usually exist for a PHA

    • The report for each process, with its methodology, team, date, revision number and sign-off.
    • The process safety information used and its revision dates.
    • The priority-order document and its rationale.
    • The recommendation log with resolutions, owners and evidence.
    • Records of updates and revalidations, kept for the life of the process.
    • The assumptions record for use in the next analysis.
    • A note of how the team's composition met the standard.

    What a software tool needs to capture for PHA

    • A process record that links each analysis to the process safety information and drawings used.
    • A method field and a reason, so a mixed approach across one process is visible.
    • Findings grouped by the elements the standard lists, not as one free-text report.
    • Recommendation tracking that keeps an item open until its resolution is documented.
    • A revalidation date with reminders and a review of the changes since the last analysis.
    • Roles for the team leader, the process-experienced member and the member who knows the method, so the required mix is visible.
    • Retention of every version for the life of the process, with a read-only export.

    Catalog profiles documenting process safety management

    The process safety rule produced this list. It does not show support for a particular method, for revalidation reminders or for retention requirements, which should be tested.

    Same rule for every product: tagged “Process Safety”, “Barrier Management”, “Risk Management”, “Risk Assessment”, “Control of Work”, “Permit to Work” or “Asset Integrity”, with a sourced process safety (PHA, barrier or management-of-change) capability in its record, or one the vendor stated to us, labelled as vendor-stated. Documented and conditional capabilities qualify; check the linked scope before treating a module as included.

    Tekmon pays for a sponsored placement (above); its place in this list follows the same rule as every entry. How lists are ordered

    All 23 matching profiles are shown. Documentation review, not hands-on testing or a claim of compliance.

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    Frequently asked questions

    Which method must a PHA use?

    OSHA requires one or more of the listed methodologies, appropriate to the hazards of the process: what-if, checklist, what-if/checklist, HAZOP, FMEA, fault tree analysis or an appropriate equivalent. Appendix C says the choice depends on factors such as process knowledge, size and complexity.

    How long are PHA records kept?

    Under 1910.119 the employer retains the process hazard analyses and their updates or revalidations for each covered process for the life of the process. Other regimes set their own retention rules.

    Does a PHA need a team?

    Yes under 1910.119: a team with engineering and process operations expertise, including a member with experience of the process and one who knows the methodology. Appendix C says a team can be as small as two people.

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