Policy paper

Control of Major Accident Hazards (COMAH) offences

Updated 21 February 2024

Applies to England

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COMAH Regulations 2015

How they are treated

The COMAH Regulations are treated as health and safety regulations under the Health and Safety at Work, etc Act 1974 (HSWA).

Enforcement

The COMAH Regulations are enforced by the competent authority. This is the Environment Agency acting jointly with the Health and Safety Executive (HSE) or the Office for Nuclear Regulation (ONR).

Principles and procedures of enforcement

A memorandum of understanding sets out the general policy, principles and working arrangements for the competent authority.

HSE and ONR enforcement will normally lead in dealing with issues concerning the health and safety of people. The Environment Agency will normally lead on issues concerning environmental protection.

The competent authority has established procedures for enforcement activities. These apply in addition to Environment Agency enforcement procedures and are available to COMAH regulatory officers and regulatory team leaders authorised to access HSE’s extranet at:

Guidance and templates.

Choice of regulation

Many COMAH establishments are also subject to regulation under the Environmental Permitting Regulations (EPR). For these sites, there will generally be the choice whether to take action under COMAH or under EPR and HSWA (for HSE).

A case by case examination is required but the following general principles should apply:

  • for major accidents, COMAH is the most appropriate regime and the competent authority should look to use COMAH
  • alleging both a COMAH Regulation 4 breach (failure to take all measures necessary) and an EPR offence (failure to use best available technique) may be seen by the courts as duplication - however, an offence contrary to another regime can be alleged in addition to the Regulation 4 COMAH offence if its inclusion will enable a court to sentence for the full extent of the occurrence

Guidance

Enforcement actions under COMAH are guided by use of the Enforcement Management Model (EMM) within the COMAH competent authority.

Guidance on EMM and its use is available to COMAH officers and regulatory team leaders authorised to access HSE’s extranet at:

Guidance and templates.

Section 33(1)(c) HSWA 1974:

Contravention by an operator of any relevant requirement of the COMAH Regulations 2015.

The standard criminal and offence specific responses are:

  • warning
  • formal caution
  • prosecution
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