the occurrence of an accident initiator where the protection functioned properly to
preclude a release of a highly hazardous chemical, or
the determination that a protection system was out of service such that if an initiating
event had occurred, a release of the highly hazardous chemical would have taken place.
Normally Unoccupied Remote Facility
A facility that is operated, maintained, or serviced by workers who visit the facility only
periodically to check its operation and to perform necessary operating or maintenance tasks.
No workers are regularly or permanently stationed at the facility. Such facilities are not
contiguous with, and must be geographically remote from, all other buildings, processes, or
An expression of the likelihood that an event or event sequence will occur during an interval
of time, or the likelihood of the success or failure of an event on test or on demand. By
definition, probability must be expressed as a number ranging from 0 to 1.
Any onsite [Q25] activity that involves a highly hazardous chemical, including any use,
storage, manufacturing, handling, and/or movement of a highly hazardous chemical. Any
interconnected group of vessels is considered a single process. Vessels with no physical
interconnections located such that an accident in one vessel could spread to adjacent vessels
are considered a single process.
Modification of a facility, process, procedure or operation that is significant enough to alter
the process safety information (see Section 2.10, Management of Change).
Process Hazards Analysis (PrHA)
The application of one or more analytical methods to identify and evaluate process hazards
for the purpose of determining the adequacy of or need for control measures.
Process Safety Management (PSM)
The application of management principles, methods, and practices to prevent and control
accidental releases of process chemicals or energy.
The Occupational Safety and Health Administration's "Rule for Process Safety Management
of Highly Hazardous Chemicals," 29 CFR 1910.119.
Replacement in Kind
A replacement that satisfies the design specification.