7.13.2 Definition of Safety
Terms and Acronyms
The meanings of some terms and acronyms are unique to this
section and are therefore included here to aid the reader.
Fail Safe: A design feature that either ensures that the
system remains safe, or, in the event of a failure, forces the system to
revert to a state which will not cause a mishap.
Hazard: A condition that is prerequisite to a mishap.
Hazard Probability: The aggregate probability of
occurrence of the individual events that create a specific hazard.
Hazardous Material: Anything that due to its chemical,
physical, or biological nature causes safety, public health, or environmental
concerns that result in an elevated level of effort to manage.
Mishap: An unplanned event or series of events that
result in death, injury, occupational illness, or damage to or loss of
equipment or property or damage to the environment. An accident.
Risk: An expression of the possibility of a mishap in
terms of hazard severity and hazard probability.
Risk Assessment: A comprehensive evaluation of the risk
and its associated impact.
Safety: Freedom from those conditions that can cause
death, injury, occupational illness, or damage to or loss of equipment or
property or damage to the environment.
Safety Critical: A term applied to a condition, event,
operation, process or item of whose proper recognition, control, performance
or tolerance is essential to safe operation or use; e.g., safety critical
function, safety critical path or safety critical component.
Safety-Critical Computer Software Components: Those
computer software components and units whose errors can result in a potential
hazard, or loss of predictability or control of a system.
System Safety: The application of engineering and
management principles, criteria, and techniques to optimize safety within the
constraints of operational effectiveness, time, and cost throughout all phases
of the system life cycle.