Process Safety Management (PSM)

Process safety management is an analytical tool focused on preventing releases of any substance defined as a "highly hazardous chemical" by the EPA or OSHA. Process Safety Management (PSM) refers to a set of interrelated approaches to managing hazards associated with the process industries and is intended to reduce the frequency and severity of incidents resulting from releases of chemicals and other energy sources (US OSHA 1993). These standards are composed of organizational and operational procedures, design guidance, audit programs, and a host of other methods.

Elements of Process Safety Management

• Process Safety Information
• Process Hazard Analysis
• Operating Procedures
• Training
• Contractors
• Mechanical Integrity
• Hot Work
• Management of Change
• Incident Investigation
• Compliance Audits
• Trade Secrets
• Employee Participation
• Pre-startup Safety Review
• Emergency Planning and Response

All of those elements mentioned above are interlinked and interdependent. There is a tremendous interdependency of the various elements of PSM. All elements are related and are necessary to make up the entire PSM picture. Every element either contributes information to other elements for the completion or utilizes information from other elements in order to be completed.

Process Safety Information

Information pertaining to the hazards of the highly hazardous chemicals in the process should consist of at least the following:

• Toxicity information
• Permissible exposure limit
• Physical data
• Reactivity data
• Corrosivity data
• Thermal and chemical stability data
• Hazardous effects of inadvertent mixing of different materials that could foreseeably occur.

Information pertaining to the technology of the process should include at least the following:

• A block flow diagram or simplified process flow diagram
• Process chemistry and its properties
• Maximum intended inventory
• Safety upper and lower limits for such items as temperatures, pressures, flows or compositions
• An evaluation of the consequences of deviations, including those effecting the safety and health of the employees.

Information pertaining to the equipment in the process should include following:

• Materials of construction
• Piping and instrument diagram (P&ID’s)
• Electrical classification
• Relief system design and design basis
• Ventilation system design
• Design codes and standards employed
• Material and energy balances for processes built after May 26, 1992
• Safety system ( for example interlocks, detection or suppression systems)

The employer should document that equipment complies with recognized and generally accepted good engineering practices (RAGAGEP) For existing equipment designed and constructed in accordance with codes, standards or practices that are no longer in general use, the employer should determine and document that the equipment is designed, maintained, inspected, tested and operating in a safe manner.