Glossary - DOE-HDBK-1100-20040010

DOE-HDBK-1100-2004

GLOSSARY

Accident, Accident Event Sequence

An unplanned event or sequence of events that has an undesirable consequence.

Aggregate Threshold Quantity

The total amount of a hazardous chemical contained in vessels that are interconnected, or

contained in a process and nearby unconnected vessels, that may be adversely affected by

an event at that process.

Catastrophic Release

A major uncontrolled emission, fire, or explosion, involving one or more highly

hazardous chemicals that presents serious danger to employees in the workplace or to the

public.

Employee

Under 29 CFR 1910.119, "Process Safety Management of Highly Hazardous Chemicals,"

an hourly, salaried, or contract person who works at a facility and comes in direct contact

with a covered process.

Event

An occurrence involving process, equipment, or human performance either internal or

external to a system that causes system upset. In terms of accidents, an event is either a

cause or a contributing cause of a "near miss" or accident, or a response to the accident

initiating event.

Facility

The buildings, containers, or equipment that contain a chemical process.

Flammable Gas

A gas that, at ambient temperature and pressure, forms a flammable mixture with air at a

concentration of 13 percent by volume or less; or a gas that, at ambient temperature and

pressure, forms a range of flammable mixtures with air wider than 13 percent by volume,

regardless of the lower limit.