Process Safety Management and Hazardous Materials Handling
Process Safety Management and Hazardous Materials Handling
This domain tests prevention of catastrophic releases in processes involving highly hazardous chemicals, and the safe handling of materials outside PSM-covered processes.
Core rules
- OSHA 1910.119 PSM applies to processes at or above threshold quantities of listed highly hazardous chemicals, flammable liquids or gases in a process, and certain reactive materials. It has 14 elements, including process safety information, process hazard analysis, operating procedures, training, contractor safety, pre-startup safety review, mechanical integrity, hot work, management of change, incident investigation, emergency planning, compliance audits, trade secrets, and employee participation.
- PHA methods include HAZOP, what-if, checklist, and fault tree. HAZOP uses guide words such as no flow, more flow, less flow, reverse flow, and contamination at nodes.
- Management of change covers changes to chemicals, technology, equipment, and procedures; replacement in kind still requires documentation.
- Pre-startup safety review confirms construction meets design, procedures and training are in place, and PHA recommendations are resolved before introducing hazardous chemicals.
- Hazardous materials handling requires GHS-compliant SDS and labels, compatibility review, segregation, spill response, and secondary containment.
Worked example
A HAZOP node on a toluene transfer line considers no flow. Causes include pump failure, closed valve, and blocked strainer. Consequences include loss of cooling or downstream overheating if the toluene is a feed. Existing safeguards are a low-flow alarm and operator rounds. The team judges the alarm alone insufficient and recommends a high-temperature interlock. The reasoning: the guide word creates a deviation, the cause-consequence chain identifies the hazard, and the safeguard is evaluated for independence and effectiveness.
Traps
- Treating PSM as paperwork rather than a living safety system.
- Conducting a PHA without a multi-disciplinary team.
- Exempting replacement in kind from MOC without documented evaluation.
- Relying on SDS alone for compatibility and reactivity decisions.