Control of Major Accident Hazards Regulations

A new Directive on the control of major accident hazards involving dangerous substances known as Seveso III was published on 24 July 2012 by the European Commission. It amends and repeals the Seveso II Directive from 29 September 2015.

The regulations

The Control of Major Accident Hazards Regulations (Northern Ireland) 2000 (which implemented the Seveso II Directive)  were repealed on 28th September 2015 to be replaced with the Control of Major Accident Hazards Regulations (Northern Ireland) 2015 that implements the majority of the Seveso III Directive.

Seveso III Directive

The Seveso III Directive addresses the consequences to the regulation of major accident hazard sites of the repeal of the Dangerous Substance Directive and Dangerous Preparations Directive (implemented in Northern Ireland as CHIP Regulations) and their replacement with European Regulation (EC) No 1272/2008 on classification, labelling and packaging of substances and mixtures implemented in Northern Ireland as the CLP Regulation.

Public information on establishments subject to COMAH 2015

Public information about COMAH establishments in Northern Ireland (NI) has been made available via this website to enable people to find out about COMAH establishments in their local area.

The information about each COMAH establishment has been provided by its operator. All establishments are required to provide certain categories of information, while Upper Tier establishments are also required to provide some further details. The Register can be accessed on COMAH Public Information Northern Ireland.


The Seveso III Directive does not fundamentally alter the regulatory regime laid out in Seveso II but does strengthen a number of areas such as public access information and standards of inspection.

Threshold quantities

Threshold quantities above which the Regulations apply are listed for a range of named dangerous substances (Part II, Schedule 1) and also for some categories of dangerous substances including 'Health, 'Physical', 'Environmental' and 'Other' Hazards.


The Regulations are enforced by a Competent Authority comprising theHealth and Safety Executive NI (HSENI) and NIEA. NIEA are responsible for assessing measures to protect the environment under the Regulations. This includes examining operators’ safety reports and carrying out inspections on establishments covered by the regulations.

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