Internationally accepted good practice in the design and use of safety instrumented systems address many of the same issues that are covered by the COMAH regulations. If a site follows a standard such as BS IEC 61511 therefore, much of the information required of them by COMAH should be readily available.
This section of guidance breaks down common issues between COMAH and BS IEC 615111 into typical HSE Assessment team areas to act as a prompt for possible issues to include in an intervention plan.
Check that HAZOPs or other risk assessment tools have correctly identified safety critical functions.
Audit the site's approach to identifying hazard and hazardous events of the process and associated equipment.
Carry out joint inspection with C&I specialist on key safety instrumented systems as required.
Liaise with other disciplines on safety integrity of measures in place, and human factors issues as required. C&I Inspector to provide input on integrity of instrumented systems and alarm systems.
Audit a sample of safety instrumented control functions to determine suitable allocation of safety functions to protection layers.
Check that the required safety instrumented functions have been identified.
Audit the designed safety integrity level of the safety instrumented functions.