The aim of the fire and explosion hazard management strategy is to reduce the risks from fires and explosions to as low as reasonably practicable (ALARP). The Oil and Gas UK guidance [1] and COMAH regulations [2] identify the following aims:
• Identify, analyse and understand all fire and explosion hazards and associated effects.
• The risk corresponding to fire and explosion hazards identified above should be as low as reasonably practicable.
• A suitable order of priority, and a suitable combination, of prevention, detection, control and mitigation systems for fire and explosion hazards should be implemented and supported throughout the life cycle of the offshore platform. In other words risks should be reduced to ALARP using inherently safe design principles.
• The above prevention, detection, control and mitigation systems should have performance measures proportionate to the required risk reduction.
• The design, operation and maintenance of the above prevention, detection, control and mitigation systems should be carried out by competent staff.
• Any changes that may occur throughout the lifecycle of the installation, and that may affect the likelihood and / or consequence of any fire or explosion hazard event (and therefore may make the risk on the installation deviate from an ALARP state) should be identified and assessed. The prevention, detection, control and mitigation systems should be modified and updated as necessary to take into account any such changes.
Key concepts in FEHM
Performance standards
The HSE document Successful Health and Safety Management (HSG 65) states that setting performance standards are essential if policies are to be translated from good intentions into a series of co-ordinated activities and tasks. Performance standards should:
• Set out clearly what people need to do to contribute to an environment which is free of injuries, ill health and loss.
• Help identify the competences which individuals need to fulfil their responsibilities.
• Form the basis for measuring individual, group and organisational performance.
Performance standards should link responsibilities to specific outputs, by specifying:
• Who is responsible.
• What are they responsible for.
• When should the work be done.
• What is the expected result.
ALARP
The concepts underlying ALARP are given in the HSE Reducing Risks, Protecting People (R2P2) document and further details are provided on the HSE website. Some of the main points are summarised below:
• Risk criteria and tolerability: The HSE framework for tolerability of risk shows three regions:
High risk region - risk is unacceptable regardless of the level of benefit associated with the activity;
Intermediate risk region - risk can be tolerated if it can be proved that there is gross disproportion between risk and further risk reduction, and if there is a system in place to ensure that risks are periodically reviewed to examine whether further controls are appropriate; and
Low risk region - no additional measures are necessary except maintaining usual precautions.
• In the ALARP context the duty holder is required to take into account the individual risk and the societal risk (risk of multiple fatalities) bearing in mind that other aspects of societal concern have already been reflected in the regulatory regime in which the duty holder is operating;
• The HSE guidance indicates that it is good practice (but not enforceable) to apply the
principles of prevention as a hierarchy;
• Good design principles aim to eliminate a hazard in preference to controlling the hazard, and controlling the hazard in preference to providing personal protective equipment;
• A holistic approach is important in order to ensure that risk-reduction measures adopted to address one hazard do not disproportionately increase risk due to other hazards, nor compromise the associated risk control measures; and
• It is expected that new installation would not give rise to residual risk levels greater than those achieved by the best of existing practice.
Throughout the life cycle of the installation from the conceptual stage to the operation and decommissioning stages, risks should be assessed and risk reduction measures should be carried out if the risks are not ALARP. During the conceptual stage a wide variety of risk reduction measures are available, including prevention and elimination, while at later stages in the life cycle the majority of risk reduction measures available would fall under the control and mitigation categories.
The figure below shows the various categories of available risk reduction measures and their variation from least to most preferred, where it can be seen that inherent safety is the most preferred risk reduction measure.
Selected references
Some of the key documents that provide guidance on fire and explosion hazard management are listed below.
1) Reducing Risks, Protecting People, HSE, 2001
2) A guide to the Control of Major Accident Hazards regulations 1999, HSE, 1999
3) Reducing Risks, Protecting People, HSE, 2001
4) Interim Guidance Notes for the design and protection of topside structures against explosion and fire, SCI, 1992
5) Risk and Emergency Preparedness analysis, NORSOK Z-013, 2001
6) Recommended practice for the design of offshore facilities against fire and blast loading, API RP 2FB, 2006