Risk
Reduction By Layers Of Protection
In the EC, national legislation Implementing the
Framework Directive 86/391 (The Health and Safety at Work Act)
requires employers to identify any hazards to people associated
with their work activities and to assess the risks from these
hazards.
When Hazards have been identified in automated
systems it is necessary to determine the protection that is in
place to stop the Hazards being realised and giving harm to
personnel. Each layer of protection needs to be analysed to
determine if the risk reduction by means of the protection is
acceptable and can be demonstrated to adequately protect
personnel.
Some of these protection layers may be
instrumented systems as shown in the diagram These systems need
to be designed to ensure they provide the necessary risk
reduction as determined by IEC61508/61511
