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Process Hazard Analysis(PHA)

Risk & Failure Analysis
processchemicalmechanical

Definition

A thorough, organized, systematic approach for identifying, evaluating, and controlling hazards of processes involving highly hazardous chemicals. PHA is a regulatory requirement under OSHA PSM (29 CFR 1910.119) and must be conducted using recognized methodologies such as HAZOP, What-If, Checklist, FMEA, or Fault Tree Analysis. PHAs must be updated and revalidated at least every 5 years.

Context

PHAs are the primary mechanism for identifying process safety hazards that drive asset integrity requirements. The safeguards and recommendations from PHAs create inspection, monitoring, and maintenance requirements that are managed through integrity management programs. In Reliatic, PHA recommendations that affect equipment integrity are tracked as actions.

Examples

  1. A PHA revalidation identifies that a previous safeguard (manual monitoring of reactor temperature) is inadequate for the current throughput, recommending upgrade to an automated safety instrumented function — tracked as an action in Reliatic.
  2. A HAZOP conducted as part of an MOC review for increasing operating pressure identifies 3 new hazard scenarios requiring additional mechanical integrity measures: increased inspection frequency, installation of a pressure relief device, and enhanced corrosion monitoring.

Applicable Standards

  • 29 CFR 1910.119
  • IEC 61882
  • CCPS Guidelines

Related Terms

Hazard Identification(HAZID)

A systematic process for identifying hazards — sources of potential harm — associated with a facility, process, or activity. Hazard identification techniques include HAZOP (Hazard and Operability Study), What-If analysis, checklist analysis, and preliminary hazard analysis (PHA). HAZID is the first step in risk assessment: risks cannot be managed if the hazards are not first identified.

OSHA PSM(PSM)

Process Safety Management — OSHA's regulatory standard (29 CFR 1910.119) requiring employers to identify, evaluate, and control hazards associated with highly hazardous chemicals. PSM mandates 14 elements including process hazard analysis, mechanical integrity, management of change, operating procedures, training, and incident investigation.

Management of Change(MOC)

A systematic process for evaluating, approving, implementing, and documenting changes to process equipment, technology, procedures, or organizational structure that could affect safety, health, environment, or operations. MOC ensures that all changes are reviewed for potential hazards, that appropriate safeguards are implemented, and that affected personnel are informed and trained before the change is implemented.

Failure Mode and Effects Analysis(FMEA)

A systematic, proactive methodology for evaluating a process, product, or design to identify all possible failure modes, determine their effects on system performance, rank them by risk priority, and recommend actions to reduce or eliminate the highest risks. FMEA examines each component's potential failure modes, their causes, effects at local/system/end levels, current controls, and risk priority numbers.

Risk Assessment

The overall process of risk identification, risk analysis, and risk evaluation. Risk assessment identifies what can go wrong (hazard identification), determines how likely it is and what the consequences would be (risk analysis), and compares the results against risk criteria to determine whether the risk is acceptable or requires treatment (risk evaluation). It is the systematic application of the ISO 31000 risk management process.

Where this appears in Reliatic

This concept is used in the FMEA & Risk module.