Control of Major Accidents

Key Legislation

• The Control of Major Accident Hazards Regulations 1999 (COMAH)
• The Control of Major Accident Hazards (Amendment) Regulations 2005
• The Control of Major Accident Hazard (Amendment) Regulations 2008
• Planning (Control of Major Accident Hazards) Regulations 1999 (SI 1999/981)
• Planning (Control of Major Accident Hazards) (Scotland) Regulations 2000 (SI 2000/179)
• The Planning (Control of Major Accident Hazards) (Scotland) Regulations 2009

COMAH applies mainly to the chemical / refining / petro-chemical industry and also to some storage activities or sites where threshold quantities of dangerous substances identified in the Regulations are kept or used.

The COMAH regulations ensure that every operator shall take measures to prevent major accidents. Unlike its predecessor, (CIMAH), the COMAH Regulations place a stronger emphasis on the protection of the environment as well as human health. The main effect of the 2005 amendment was to broaden the scope of COMAH. New named substances are added including petroleum substances. The changes reflect lessons learned from major accidents in Europe and the EU working group on carcinogens, fertilisers and substances dangerous for the environment.

Under the COMAH regime there is a fundamental requirement for operators to perform and environmental risk assessment to clearly demonstrate that risks have been identified and prevention measure put in place.

Every operator shall prepare and keep a document setting out their policy with respect to the prevention of major accidents; known as the Major Accident Prevention Policy (MAPP). This policy is designed to guarantee a high level of protection for persons and the environment by appropriate means, structure and management system.

The regulations also require operators to prepare an onsite emergency plan which should include measures for site clean up and remediation following an incident.

The COMAH 2008 Amendment Regulations remove the words 'installation' and 'safety case' and replaces them with 'establishment' and 'safety report', respectively.

The COMAH regime has been updated in Scotland to increase the range of dangerous substances for which consent must be obtained for storage or processing; the definition of these substances; and the amounts allowed before consent must be obtained.

A proposal for a new updated replacement COMAH Directive is currently under consideration (see Pending Legislation).

Supporting Legislation

• Health and Safety at Work Act 1974
• EC Directive 96/82/EC on the control of major-accident hazards involving dangerous substances (Seveso II Directive)

This Directive is aimed at the prevention of major accidents which involve dangerous substances and the limitation of their consequences for man and the environment, with a view to ensuring protection throughout the Community in a consistent and effective manner.

• Chemical (Hazard Identification and Packaging for Supply) Regulations 1994 as amended (CHIP)

These regulations require that chemical substances and preparations, which are dangerous for supply, as defined by CHIP be classified. This can either be as part of the Health and Safety Executives (HSE's) "Approved List" or based on available data. The regulations also require that dangerous chemicals carry special warning symbols and safety data sheets.

• Reporting of Injuries, Diseases and Dangerous Occurrences Regulations 1995 (RIDDOR)

Requires the reporting of work related accidents,diseases and dangerous occurrences. It applies to all work activities but not to all incidents.

• Control of Substances Hazardous to Health Regulations 2002 (COSHH)

Requires employers to control exposures to hazardous substances to protect both employees and others who may be exposed from work activities.

1. The Chemicals (Hazard Information and Packaging for Supply) (Amendment) Regulations 2008

The CHIP 2008 Amendment Regulations amends the Control of Major Accident Hazards Regulations 1999 to provide for the Health and Safety Executive to be the enforcing authority except in the circumstance provided for.

These regulations set out the planning requirements for operators of establishments where dangerous substances under COMAH 1999 are present.

A guide to the Control of Major Accident Hazards Regulations 1999 (as amended) (ISBN 071766175X)

This revised guidance on the COMAH Regulations gives detailed advice on the scope of the Regulations and the duties imposed by them. The guidance is aimed at operators of establishments that are covered by the Regulations.

Guidance on the interpretation of Major Accident to the Environment for the Purposes of COMAH Regulation, DTI 1999 (ISBN 011753501X) available from the Stationery Office or available for download on the Defra website (pdf).

This guidance is a 1999 update on major accidents to the environment, reviewed to ensure its scope is adequate for the purposes of COMAH.

Guidance on the Environmental Risk Assessment Aspects of COMAH Safety Reports, COMAH Competent Authority 1999

Preparing Safety Reports: Control of Major Accident Hazard Regulations 1999, HSE 1999 (ISBN 0717616878)

A guide to the reporting of injuries, diseases and dangerous occurrences regulations 1995, HSE 1999 (ISBN 0717610128)

Emergency Planning for Major Accidents, Control of Major Accident Hazard Regulation 1999, HSE 1999 (ISBN 0717616959)

COMAH Safety Report Assessment Manual, HSE 2003 - available on the web

Link to HSE Books Website

No consent is required but operators must produce and maintain a Major Accident Prevention Policy (MAPP) as outlined below.

The Safety Report should also include sufficient particulars to demonstrate that the operator has established a Safety Management System (SMS) including organisational structure, responsibilities, practices, procedures, processes and resources for determining and implementing the Safety Report.

Top-tier establishments are not required to produce a documented version of the Safety Report and SMS separately as under Regulation 7 both can be incorporated in the Safety Report.

Lower-tier establishments must produce a stand alone MAPP as they are not required to produce a Safety Report. Within this document lower-tier site operators must demonstrate that an SMS has been established.

All operators are also required under Regulation 9 to produce Emergency Plans.

Any establishment is subject to the COMAH 1999 Regulations (as Amended), if it has on site any substance specified in Schedule 1 of the COMAH regulations above the qualifying quantity.

Substances listed include liquefied extremely flammable gases (including LPG) and natural gas (whether liquefied or not). Substances classified as toxic, oxidising, explosive, flammable and dangerous for the environment are also included.

There are two threshold quantities:

• establishments with quantities equal to or greater than the upper threshold are known as top-tier establishments;
• establishments with lower quantifies, but which are equal to or greater than the lower threshold are known as lower-tier establishments.

Operators of existing installations that come under COMAH are required to notify the Competent Authority (HSE and SEPA/EA) of the details of their activities as detailed within Schedule 3 of the COMAH regulations, unless the information has already been supplied in a CIMAH or COMAH Safety Report.

Operators of new establishments should send notification within a reasonable time before the start of construction, normally 3 to 6 months. Additional notification is only required prior to the commencement of operations if any of the details in the pre-construction notification were missing or have changed.

Regulation 3 of COMAH states that all operators of establishments subject to COMAH must have a Safety Report. This document must be proportionate to the major accident hazards presented by the establishment and should include their overall aims and principals of action with respect to the control of major accident hazards.

Schedule 2 of the COMAH regulations lists principals to be taken into account when preparing a MAPP, including:

1. Organisation and Personnel

2. Identification and evaluation of major hazards

3. Operations control

4. Management of change

5. Planning for emergencies

Regulation 7 requires operators of top-tier establishments to submit a Safety Report, the purpose and contents of which are described in Schedule 3.

The Safety Report must include:

1. Information on the management system of the organisation and the establishment with a view to major accident prevention.

2. A description of the environment of the site including its geographical location, meteorological, geological and hydrographic conditions and if necessary its history. This section must also include the human environment of the plant including other establishments, local communities and their sensitivities.

3. Description of installation including main activities, processes and operation methods. This section must also include information on the chemical characteristics of substances contained on site.

4. Identification and accidental risks analysis and prevention methods, including potential triggers and consequences both internal and external and a description of the technical parameters and equipment used for the safety of installations.

5. Measures of protection and intervention to limit the consequences of an accident including equipment both on and off site, organisation of alert and intervention procedure and a summary of the elements necessary for drawing up the on-site Emergency Plan.

Regulation 9 stipulates that all establishments subject to COMAH must produce an Emergency Plan, however the procedure varies depending on the classification of the site:

• Top-tier establishments must produce two emergency plans in writing:

1. On-site emergency plan, which is prepared by the operator, to specify the response of those who work on site; and

2. Off-site emergency plan, which is prepared by the local authority, to specify the coordinated response of agencies to an emergency which has off-site effects.

• Lower-tier sites do not have to produce a specific emergency plan, however the MAPP required by Regulation 5 should include information on the management system and procedures for identifying foreseeable emergencies. The level of planning for these emergencies should be proportional to the probability of the accident occurring.

Schedule 5, Part 1 of COMAH describes the objectives of Emergency Plans which are referred to in Regulations 9(1) and 10(1) as follows:

1. To contain and control incidents so as to minimise their effects, and to limit damage to persons, the environment and property;

2. To implement the measures necessary to protect persons and the environment from the effects of major accidents;

3. To communicate the necessary information to the public and to the emergency services and authorities concerned in the area;

4. To provide for the restoration and clean-up of the environment following a major accident.

Regulation 9(3) and Schedule 5 provide for the production of an on-site emergency plan. The on-site plan must include:

• Names and positions of persons authorised to set emergency procedures in motion;
• Person in charge of and coordinating the on-site response;
• Name or position of the person with responsibility for liaising with the local authority (off-site emergency plan);
• For foreseeable scenarios, a description of the action which should be taken, including a description of the safety equipment and the resources available;
• Arrangements for limiting the risks to persons on site including, warning, and alert procedure;
• Arrangements for providing early warnings of the incident to the local authority, to set the off-site emergency plan in motion, the type of information which should be contained in the initial warning and the arrangements for the provision of more detailed information as it becomes available;
• Arrangements for training staff in the duties they will be expected to perform, and where necessary coordinating this with the emergency services;
• Arrangements for providing assistance with off-site mitigatory actions.

Local authorities for the area where a top-tier site is located must prepare in writing, an adequate emergency plan for dealing with the off-site consequences of possible major accidents. This document must include the following:

• Names of positions of persons authorised to set emergency procedures in motion and take charge of and coordinate off-site action;
• Procedure for the early warning of incidents, alert and call out procedure;
• Coordinating resources to implement the off-site emergency plan;
• Arrangements for providing assistance with on-site mitigatory action;
• Arrangements for all off-site mitigatory action;
• Arrangements for providing the public with specific information relating to the accident and the behaviour which they should adopt.

Local authorities must also consult with the public when preparing an off-site emergency plan.

Top-tier establishments:

New establishments must have a MAPP available from the day that the regulations apply (1st April 1999):

Other establishments have to prepare a MAPP as quickly as possible after coming into scope and should discuss the timescale with the Competent Authority (HSE/EA/SEPA)

Lower-tier establishments:

New establishments must submit a COMAH report "within a reasonable period of time prior to the start of operations". Start of operation is taken as the first time that dangerous substances are introduced into the plant including commissioning. This is normally taken to mean up to six months before operation.

Existing establishments must submit a COMAH report when a review or update is due, or when changes in the establishments require and update. The minimum period for review is five years.

It is not necessary to submit a MAPP document to the Competent Authority (HSE/EA/SEPA), unless requested to do so. It will usually be requested before a visit and should be kept available for inspection. Inspectors will use it along with other data and information to plan and structure inspections.

The regulations provide for the Competent Authority (HSE and SEPA/EA) to undertake regular inspections and investigations where necessary.

Operators must implement procedures for the ongoing assessment of compliance with the objectives set by both the MAPP and the SMS.

This must include mechanisms for investigation and corrective action in cases of non-compliance. Following a major accident the Competent Authority will make a full analysis of the technical, organisational and managerial aspects of the major accident and collect by inspections, investigation or other appropriate means, the information necessary for that purpose. Appropriate action will them be taken to ensure that the operator takes any necessary remedial measures.

All occurrences which qualify as major accidents must be reported. A major accident is defined under Regulations 2(1) of COMAH as,

"an occurrence (including in particular, a major emission, fire or explosion) resulting from uncontrolled developments in the course of the operation of any establishment and leading to serious danger to human health or the environment, immediate or delayed, inside or outside the establishment, and involving one or more dangerous substances".

The following information must be provided when a major accident is reported:

the circumstances of the accident;

the dangerous substances involved;

any data available for assessing the effects of the accident on persons and the environment;

the emergency measures taken;

steps proposed to prevent the recurrence of such an incident;

such other information in the operators possession as will enable the Competent Authority (HSE and SEPA/EA) to notify the European Commission.

A European Council Directive Decision, 96/82/EC, on the control of major-accident hazards involving dangerous substances, has produced a form to be used in reporting major industrial accidents.

In respect of enforcement the COMAH regulations fall under the Health and Safety at Work Act 1974. The duty placed in the Competent Authority (HSE and SEPA/EA) by these regulations shall not be an offence, and Section 33(1)(c) of the 1974 Act shall have effect accordingly.

Since the December 2005 explosions and major fire at the Buncefield, Herts, Oil Storage Depot, worldwide perception about such sites has changed. The Health and Safety Commission established an independent investigation. Finding of the investigation are accessible via the Buncefield Investigation website.

The HSE have established a Task Group to report on the incident.

Bulk storage

To improve protection of people and the environment the EA/SEPA/HSE has consulted on the future policy of the storage of bulk hazardous chemicals; specifically petrol. This review is in response to many recommendations of the Buncefield investigation. The potential change in policy would apply immediately to any new sites. It is estimated that existing storage sites may take 10-20 years to comply with best practice.

The Environmental Liability Directive was adopted in 2004 and was required to be implemented by 30 April 2007.  The Directive enforces strict liability for prevention and remediation of environmental damage to ‘biodiversity’, water and land from specified activities and remediation of environmental damage for all other activities through fault or negligence. 

The Environmental Liability Directive is now implemented in England and Wales. In Scotland The Environmental Liability (Scotland) Regulations 2009 came into force on 24th June 2009.