Fortunately, major accidents are rare in the UK.  Nevertheless, sites deemed to be at risk of having major accidents are regulated and enforced by the Health and Safety Executive (HSE) through the Control of Major Accident Hazards Regulations (COMAH 15).  These Regulations implement the Seveso III Directive (except for the land-use planning requirements).  COMAH 15 exists because the consequences of sites getting it wrong are catastrophic for all stakeholders – individuals, the business, the environment, and the community at large.

It is essential that organisations adopt a proactive approach to managing major accident hazards risks.  There is a shared belief in UK society that everyone at work should go home safe to their loved ones at the close of business.

Management of COMAH risks starts from the planning and design stage through to operational stages such as storage, production, usage, disposal and decommissioning.  We have learned that most organisations get it right at the planning and design stage.  We see organisations struggling with the operational stages e.g. a failure to identify the need for change, to communicate change, and to monitor change (to provide assurance that implemented measures are working as planned).

We believe that there is a need to separate out the day-to-day management of COMAH-related risk.  We have had to debunk myths like “the safety team is solely responsible for managing COMAH risks”.  This is simply not true.  Everyone has a part to play in ensuring that our home safe goal is met. It is essential that the organisation maintains its ‘licence to trade’ by remaining safe and legal.  Myths such as “any handling or storage of dangerous substances immediately implies that the COMAH regulations apply to the site” need to be addressed.

We have found that it is essential at COMAH sites for safety custodians to have a basic understanding of COMAH.  Involvement of the safety team is essential throughout the COMAH life cycle, in:

  • Planning and designing.
  • Construction (if the establishment is a new build).
  • Preparing and submitting all the relevant documentation to the competent authority.
  • Liaising with all relevant authorities.
  • Identifying robust prevention and mitigation measures to reduce the chance of a major accident occurring.
  • Minimising the consequences were it to occur.
  • Designing systems for the management and maintenance of COMAH-related risks.
  • Providing initial and ongoing technical support and advice to all the layers within the organisation’s organogram.
  • Providing assurance to the senior leadership team of continued compliance.
  • Ensuring that the organisation meets and maintains the required standards to operate a COMAH establishment.


Some organisations have an additional administrative function called a “stock controller” responsible for maintaining the organisation’s inventory within the agreed COMAH tier thresholds.

The senior leadership team is responsible for prioritising risks and ensuring the allocation of resources to the right priorities.

Managers have the responsibility for managing employees who interact with dangerous substances on a day-to-day basis.  This duty covers, but is not limited to – ensuring that suitable and sufficient task-based risk assessments have been completed and that the current controls reduce the risk to ALARP, ensuring adequate and appropriate initial and ongoing training for the relevant employees, ensuring adequate supervision of tasks to assure adherence to the set safety standards, ensuring the existence of opportunities to communicate risks, and providing ongoing monitoring of the risks and the relevant controls.

Broadly, the employees’ duties under the HASAWA 1974 of keeping themselves and others safe, cooperating with the employer with matters relating to health & safety, and not misusing anything provided for safety still apply here.

At Human Applications, we believe it is significantly easier to engender organisational compliance when there is an understanding of the “why” we do what we do.  No stakeholder is less significant than the other.  Everyone gets to play to make it work.

A fundamental understanding of the nuances and realities of COMAH challenges us to proactively think about our philosophy regarding the subject.

  • How do we maintain our inventories within the limits of our threshold?
  • How do we manage peak seasons? How do we make trade-offs between safety and customer’s expectations?
  • Why might we not be able to randomly take in that additional delivery? Why can’t we save some money by increasing the volumes received per time and reducing the number of deliveries?
  • Why might we not be able to act as a “temporary” holding station for another site? Why can’t we randomly use that “free and unused space” as a temporary storage area during peak season?
  • Why can’t I store this substance anywhere in the warehouse?
  • Why are we so pedantic about it, after all, we haven’t had any accident?

These are valid questions that operatives, line managers, stock controllers, senior managers have asked their resident safety teams.  What appears to be an innocuous act could result in a major accident or a breach of COMAH Regulations.  For instance, a non-COMAH site could become “a new COMAH establishment” simply by increasing their inventory to levels where the COMAH Regulations now apply.  Likewise, an increase or decrease in inventory could cause an existing establishment to move between COMAH tiers, with the former requiring more robust controls including the notification of the competent authority and the submission of additional documentation prior to the operation commencing.  A failure of which is a breach of the COMAH Regulations and other relevant health & safety legislations – the Health and Safety at Work etc. Act 1974 and the Management of Health & Safety at Work Regulations 1999.  There doesn’t have to be an “intent to harm”.  You don’t have to be a “bad person” to breach any Health & Safety legislation.  We have observed that as a precautionary measure, most organisations tend to hold quantities of inventories far less than the limit of their threshold.

Our 2-day COMAH Awareness course is designed to broaden delegates knowledge and understanding of the COMAH 2015 Regulations.  It targets those who work with dangerous substances or manage tasks/ sites where dangerous substances which could result in major accidents are produced, used, stored, or disposed.  Delegates explore the practicalities of what “good management of COMAH risks” looks like within their organisation. We are committed to demystifying the subject of “COMAH” to give stakeholders the confidence to just “get on with the job” of managing COMAH risks like they would any other safety risk.