A selection of acronyms and terms relating to PSM

  • AIChE :  American Institute of Chemical Engineers

  • ALARA:  As Low As Reasonably Achievable

  • ANSI :  American National Standards Institute

  • API :  American Petroleum Institute

  • ASME :  American Society of Mechanical Engineers

  • BPCS :  Basic Process Control System

  • CAAA :  Clean Air Act Amendments

  • CAF:  Change Authorization Form – part of PSM; Management of Change (MOC) documentation

  • CCF :  Common Cause Factor

  • CCPS :  Center for Chemical Process Safety

  • CFR :  Code of Federal Regulations

  • CMA :  Chemical Manufacturers Association

  • CMS :  Consequence Mitigation System

  • COA:  Certificate of Analysis – verification that all tests conducted on material to fulfill the order have met specifications

  • DCS :  Distributed Control System

  • EIL: Economic Integrity Level - This is the economic version of a SIL

  • EPA :  Environmental Protection Agency

  • ESD :  Emergency Shutdown System

  • FE:  Fugitive Emissions.

  • FEED:  Front End Engineering Design

  • FEL: Front-End Loading -  The project definition and planning cycle up to the Authorization for Expenditure

  • FIL: Financial Integrity Level -  Same as EIL

  • FMEA:  Failure Mode Effects Analysis - Based on the investigation of the potential of each individual component failure

  • FMP :  Fault Management Program

  • FSA :  Functional Safety Assessment

  • FTA:  Fault Tree Analysis - Logical model and (sometimes) quantification of an identified major process hazard event

  • HAZCOM:  Hazard Communication

  • HAZOP:  Hazard and Operability Study

  • HAZWOPER:  Hazardous Waste Operations and Emergency Response

  • HMB: Heat and Material Balance Sheets - A Heat and Material Balance is a companion to the Process Flowsheets

  • HMI :  Human-Machine Interface

  • HRF:  Hazard Reduction Factor - part of LOPA; a measurement of performance of an ISS, where HRF = 1/PFD

  • IPL:  Independent Protection Layer – part of LOPA

  • ISA :  Instrumentation, systems, and automation society

  • ISA:  Instrument Society of America

  • ISO:  International Standards Organization

  • ISS: Instrumented Safety System - Same as SIS

  • LOPA: Layer of Protection Analysis - A PHA method used to evaluate safety integrity of process operations; provides order of magnitude approximation of the risk of a scenario.  LOPA uses a numerical calculation to measure adequacy of protection layers (e.g. alarms, RVs, control loops) against potential consequences of deviations such as loss of containment and personnel exposure (LOPA Ratio = TMEL/MEL).

  • MF or P&ID: Mechanical Flow Sheet - A mechanical drawing of the process flow that schematically represents plant configuration by region for record, initial installation, continuous update, and process review. A MF shows all process equipment, piping configuration, utility details and control equipment configuration and function.

  • MI: Mechanical Integrity - Part of PSM that maintains integrity of equipment.  Requires written maintenance procedures; trained maintenance personnel; scheduled inspections & tests per RAGAGEP (Recognized And Generally Accepted Good Engineering Practices)  with results documentation; immediate repair or managing equipment deficiencies to assure safe operation; quality assurance for design, construction & replacement parts.

  • MMI: Man Machine Interface - Ergonomics

  • MOC: Management of Change - Part of PSM that requires managing procedure, chemical, technology, and equipment changes.  This method is used to review changes for impacts on safety prior to the introducing a change.  MOCs also assure updates and training for the changes.

  • MSDS: Material Safety Data Sheet - A document that supplies information on the identity of hazardous chemicals and chemical makeup, health concerns, and physical hazards, exposure limits, precautions, reactivity, and other pertinent information. 

  • MTBF: Mean Time Between Failure - A calculation of the average time for an item to fail

  • MTTF: Mean Time to Failure - Same as MTBF

  • MTTR: Mean Time to Repair - A calculation of the average time to repair an item

  • NFPA: National Fire Protection Association - An organization that establishes rules and standards for fire protection

  • NTR: Nuisance Trip Rate - See STR: Spurious Trip Rate

  • OSHA: Occupational Safety and Health Administration - A government agency that oversees safety in the workplace.  Federal Rule for OSHA is OSHA 29 CFR, Parts 1900-1999.

  • P&ID or MF: Piping & Instrumentation Diagram - See MF

  • PFD: Probability of Failure on Demand - Part of LOPA that defines the mathematical chance a piece of equipment will not function

  • PFD: Process Flow Diagram - A diagram that represents only the process flow properties without the all the other vessels, piping and equipment information

  • PHA: Process Hazard Analysis - An element of PSM that uses a systematic, comprehensive study of a process using recognized method(s) of analysis to identify process hazards, identify all ways hazardous incident can occur, evaluate likelihood and seriousness of each incident occurrence and development of recommendations to control process hazards.  This also requires periodic review of analyses of hazards of the processes.  Uses recognized methodology (e.g. HAZOP, What-If) to address specific concerns such as previous incidents and controls.

  • PL: Protection Layer - Part of LOPA to define engineered safety features or protective systems that typically involve special process designs, process equipment, administrative procedures, BPCS, and/or planned responses to protect against an imminent hazard.  Responses may be automated or initiated by human actions.

  • PM: Preventative Maintenance - Maintenance to minimize damage do to wear

  • Process Hazard:  Potential exposures to serious injuries or substantial property damage inherent and unique to a process or operation

  • PSI: Process Safety Information - All information relating to any process.  This includes but is not limited to the following:  operational conditions, piping and vessel information, chemicals composition, procedures, MFs, control loops, PSV and SIS information, etc.

  • PSM: Process Safety Management - OSHA regulation 29 CFR 1910.119 enacted in 1992 to protect workers.  A system of management to help prevent or minimize consequences of catastrophic releases of toxic, reactive, flammable, or explosive chemicals.

  • PSSR: Pre-Start-Up Safety Review - Part of PSM that requires an expert review of new and modified processes prior to start-up.  Ensures construction is consistent with design; procedures and training are in place; and PHA/MOC issues are addressed.

  • QA: Quality Assurance - Analysis of the testing methods to maintain quality of the testing

  • QC: Quality Control - Analysis of a system to help maintain quality of the products

  • QRA: Quantitative Risk Assessment - A mathametical analysis of a risk to a system or process

  • RA: Risk Assessment - Evaluation of specific risks associated with each preferred concept including potential problems and mitigation plans

  • Risk:  A potential problem.  (Frequency of cause * Seriousness of consequences) / (Effectiveness of exiting protection)

  • RMP: Risk Management Program - EPA regulation 40 CFR Part 68, a government program enacted in 1996 to protect the public and environment. The Risk Management Plan is a document that consolidates all the project risk identification, mitigation and contingency planning documents. 

  • SD: Shutdown - Stopping of a process unit or equipment

  • SIF: Safety Instrumented Function - The unit and its action that is defined as a part of a safety system

  • SIL: Safety Integrity Level - Part of LOPA; one of three possible discrete integrity levels (SIL 1, SIL 2, SIL 3) for safety instrumented systems.  SILs are defined in terms of the average PFD.

  • SIS: Safety Instrumented System -  An instrumented protection layer for a process.  Terms commonly used include ESD, Safety Interlock System and Safety Shutdown System.

  • STR: Spurious Trip Rate - An unintended system shutdown because of a malfunctioning SIS or other shutdown system

  • SWP: Safe Work Practice - Part of PSM, written procedures for safely conducting "unusual" work (e.g. confined space, LOTO); controlling access to units; permitting for hot work

  • TIL:  Target Integrity Level

  • WCS:  Worst Case Scenario

  • What-If : PHA Analysis Type based on questions spontaneously formulated by the review team for the specific process