Chemical Emergencies in Dorset

This page provides information on the chemical sites in Dorset that could, potentially, create an emergency situation, and what contingency planning measures have been put in place to mitigate the effects.


The Control of Major Accident Hazards Regulations 1999 (COMAH) came into force on 1 April 1999 and are amended by the Control of Major Accident Hazards (Amendment) Regulations 2005 from 30 June 2005. They implement Council Directive 96/82/EC known as the Seveso II Directive, as amended by Directive 2003/105/EC and replaced the Control of Industrial Major Accident Hazards Regulations 1984 (CIMAH).


The Regulations aim is to prevent and mitigate the effects of those major accidents involving dangerous substances, such as chlorine, liquefied petroleum gas, explosives and arsenic pentoxide which can cause serious damage/harm to people and/or the environment. The COMAH Regulations treat risks to the environment as seriously as those to people.


The COMAH Regulations are enforced by a competent authority (CA) consisting of:


• In England and Wales -
. The Health and Safety Executive and the Environment Agency


The chemical manufacturing industry is mainly affected by the regulations, but also some storage activities, explosives and nuclear sites and other industries, where above threshold quantities of dangerous substances identified in the Regulations are kept or used.


The substances which cause the duties to apply are detailed in Schedule 1 of the Regulations as are the quantities which set the two thresholds for application.
Operators of sites that hold larger quantities of dangerous substances ('top tier' sites) are subject to more onerous requirements than those of 'lower tier' sites. In view of this, the Regulations state that an Off-site Emergency Response Plan must be prepared and tested every three years by the Local Authority (in this case, Dorset County Council) to cover areas that may be affected outside of the site’s boundaries.


Currently, the only ‘top tier’ COMAH site in Dorset is the BP Wytch Farm gathering station near the Studland Peninsula. Organisations that have a role in responding to an incident at the site can view the Off-site Plan (which is password protected) by clicking on the link below.
Related documents:

Useful links

Dorset Emergency Contacts Directory >>
COMAH Regulations>>