Safety report assessment guidance (Technical aspects)



The Health and Safety Executive (HSE) is one of the Competent Authorities (CA) under the Control of Major Accident Hazard (COMAH) Regulations, and one of the key duties of the HSE is the assessment of Safety Reports. The assessment will be based on three levels of guidance:

  • Level 1: High level principles, which set out the general approach of the CA to the assessment of Safety Reports.
  • Level 2: Assessment Criteria and associated guidance used by the CA to evaluate the content of Safety Reports.
  • Level 3: Detailed, specific guidance, which supports the Level 2 assessment criteria.

The Level 3 guidance presented here is for the assessment of technical aspects. It is divided into four main chapters:

  • Assessment criteria
    Includes the full text of the Level 2 criteria from the Safety Report Assessment Manual (SRAM) - Part 2, Chapter 5 - and provides links to the relevant Technical Measures and other relevant documents and case studies.
  • Technical measures
    Describes the Technical Measures for prevention, control and mitigation for each of the failure modes of all systems/unit operations likely to be relevant in COMAH reports.
  • Documentation
    Provides links to enable the reader to access all the documentation that has been identified as being particularly relevant to the assessment of the technical aspects of the COMAH Safety Reports.
  • Case studies
    Brief descriptions of selected major accidents, which illustrate cases where technical measures were missing or were not implemented properly.

Guidance status and accuracy

Important note (added June 2007)

This guidance was written at the time the COMAH regulatory regime was introduced. Whilst it contains valuable information it has not been updated since that time and, as a result, should be used with caution bearing in mind that changes will have occurred since then. Most obvious is the change to the numbering system used in the Safety Report Assessment Manual (SRAM). The technical assessment criteria were '5' series criteria but the new SRAM introduced on 1st July 2006 renumbered these '12' series criteria. In addition, the standards and other documents referred to in the guidance may have moved on in the intervening period and, as a result, some of the references in this guidance will now be out of date. Less obvious is the fact that the knowledge of industry and the CA will have moved on during this period and the guidance may not therefore reflect current thinking or emphasis in some areas.

A number of authors and reviewers produced this guidance to assist the Competent Authority in assessing the content of COMAH Safety Reports. It is based on the professional judgement and experience of the authors and reviewers.

The guidance attempts to cover a very wide range of topics and documents, many of which are changing or being updated. While we have made every effort to provide accurate and up-to-date information, we cannot guarantee its correctness and completeness. This guidance should therefore be used as an aide-mémoire only.

Comments, including suggested additional text or topics, should be directed to e-mail address: [email protected]


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