ISA 84.00.01 Part 3:2004

Part 3 provides information on:
the underlying concepts of risk, the relationship of risk to safety integrity, see Clause 3;
the determination of tolerable risk, see Annex A;
a number of different methods that enable the safety integrity levels for the safety instrumented functions to be determined, see Annexes B, C, D, E, and F.
In particular, this part:
applies when functional safety is achieved using one or more safety instrumented functions for the protection of either personnel, the general public, or the environment;
may be applied in non-safety applications such as asset protection;
illustrates typical hazard and risk assessment methods that may be carried out to define the safety functional requirements and safety integrity levels of each safety instrumented function;
illustrates techniques/measures available for determining the required safety integrity levels;
provides a framework for establishing safety integrity levels but does not specify the safety integrity levels required for specific applications;
does not give examples of determining the requirements for other methods of risk reduction.