October 2015

Ensuring an effective Principal Hazard Management Plan

  • By A J Clough, General Manager, Metropolitan Colliery, Peabody Energy Australia; formerly Queensland Chief Inspector of Coal Mines

A systematic approach to reducing the risk of health and safety hazards and incidents

There has been an unprecedented rise in the fatality rate in the Australian mining industry over the last few years. The factors behind this rise are not clear, but it is noted that the increase in fatalities has occurred during a fall in commodity prices.

This article examines prevention methods and systems to deal with hazards that have the potential to result in either single or multiple fatalities. Managing the risks associated with mine ventilation is used to illustrate the principles behind the approach.

The article also touches on the broad science of human error and proposes a multi-faceted approach to controlling and preventing fatal risks.

A summary of the steps involved in developing an effective Principal Hazard Management Plan is provided.


The Queensland Coal Mining Safety and Health Regulation 2001 requires the development of Principal Hazard Management Plans to control those hazards with the potential to cause multiple fatalities.

The methodology to develop a Principal Hazard Management Plan proposed in this article is also applicable to controlling hazards that have the potential to result in either a single fatality or a serious injury.

The following definitions from the Coal Mining Safety and Health Act 1999 are relevant to the discussion on Principal Hazard Management Plans.

A hazard is a thing or a situation with potential to cause injury or illness to a person.

A high potential incident at a coal mine is an event, or a series of events, that causes or has the potential to cause a significant adverse effect on the safety or health of a person.

The difference between a hazard and an incident is that a hazard only has potential, whereas an incident has consequence. An effective Principal Hazard Management Plan will incorporate controls to reduce the likelihood of a hazard becoming an incident and also contain mitigation measures should an incident occur.

The Principal Hazard Management Plan framework

The Principal Hazard Management Plan framework is illustrated in Figure 1.


Prevention controls are the most important element in the framework as these are the primary controls to ensure that an incident does not occur. The old adage that ‘an ounce of prevention is worth a pound of cure’ applies as much to the management of principal hazards as it does to one’s personal health.

Monitoring controls are important as their role is to ensure that the prevention controls are in place and effective. These controls are for system maintenance and provide assurance that the prevention controls are implemented.

First response plans are directed at providing immediate assistance to any person affected by an uncontrolled incident. These plans come into effect when the prevention controls have failed and the hazard has developed into an incident. The first priority is mitigating the consequences to human life.

Emergency response is required for an escalating incident that requires further intervention to bring it under control. This may require both considerable resources and a strategic approach to contain a serious situation.

The Ventilation Principal Hazard Management Plan is used in this article to illustrate the application of the framework.

Prevention controls

Prevention controls lower the probability of an incident occurring. They should be high order controls and aim to eliminate the hazard altogether. The hierarchy of controls should be used to check if the prevention controls are effective.


Figure 2 illustrates a proposed relationship between the potential outcome of an incident and the hierarchy of controls. Figure 2 suggests that administration controls are totally inappropriate for an effective Principal Hazard Management Plan and, where possible, the prevention controls need to be eliminating the hazard.

An effective Ventilation Principal Hazard Management Plan would be seeking to reduce the probability of accumulations of flammable or noxious gasses, the occurrence of spontaneous combustion, accumulations of coal dust, unacceptable levels of both inhalable and respirable dust and high temperatures in the working environment.

The Ventilation Principal Hazard Management Plan should identify prevention controls at the planning stage before the workings are developed.

Ventilation simulation models can be used to ensure adequate quantities of air are available in the workings to dilute gasses and manage heat. Pressure differentials across waste workings can be minimised to reduce air leakage into areas that may be prone to spontaneous combustion. Standards are specified both though legislation and within the Ventilation Principal Hazard Management Plan to control the combustible content of accumulations of coal dust and to ensure ventilation devices are constructed to an acceptable standard.

Monitoring controls

Monitoring controls may include measurements, inspections and audits. Examples of monitoring controls in a Ventilation Principal Hazard Management Plan would include tube bundle systems, real-time gas monitoring, ventilation pressure and air velocity measurements, statutory inspections and ventilation surveys. All these serve to ensure that the ventilation system is adequately controlling the hazards.

Many organisations are now adopting the practice of monitoring critical controls. This approach involves identifying those prevention controls that are critical in ensuring an incident does not occur. The identified critical prevention controls are entered into a register and senior management ensure that these are monitored and reported on a regular basis.

It should be noted, however, that the critical controls approach will not enhance the effectiveness of poor prevention controls. It is important to challenge the prevention controls against the hierarchy of controls before they are entered into a critical control register.

First response plans

First response plans are aimed at mitigating the consequences of an incident. The uncontrolled event has occurred which means those prevention controls that aim at reducing the probability of the event occurring
have failed.

First response plans are generally aimed at protecting human life and often involve removing workers from the hazardous situation to a safe area.

First response plans are usually triggered by a Trigger Action Management Plan (TARP). The TARP will set threshold levels based on the monitoring of the hazard and will call for certain actions when the results indicate that an uncontrolled incident is occurring. The TARP will initially call for actions to bring the uncontrolled event under control. If these initial actions are unsuccessful the TARP will require the withdrawal of personnel.

In the case of the withdrawal of persons, first response plans should provide for both self-escape strategies and aided escape. The use of self-contained self-rescuers (SCSR), appropriate demarcated escape routes and change-over stations provide the infrastructure for self-escape. Compressed air breathing apparatus (CABA) enables escaping personnel to provide assistance or aided escape to their fellow workmates.

TARPS are the preferred methodology in deciding actions in relation to spontaneous combustion, ventilation failures, gas accumulations and heat.

Emergency response

Emergency response strategies are required when the first response plans have failed to bring the situation
under control.

Emergency response plans usually call for external assistance and invoke a response at both site and corporate level. Serious incidents gain public attention and organisations need to be able to manage the consequences of the loss of human life, environmental damage, loss of company assets and reputational damage.

The Ventilation Principal Hazard Management Plan should include provisions to call on the relevant Mines Rescue Service in the event of an emergency.

The Queensland Mines Rescue Service (QMRS) is a privately owned entity that is funded by industry and provides a level of emergency response for serious incidents. The QMRS has the capability of inertising a mine atmosphere after an explosion or a fire. The Górniczy Agregat Gaśniczy (GAG) is a Polish jet engine that QMRS can affix to a mine entrance and the exhaust used to displace oxygen from the underground atmosphere (Figure 3).


Human error and the principal hazard management framework

It would be a great result if a well designed and implemented Principal Hazard Management Plan was 100 per cent effective. The reality is humans, on occasion, will make a conscious decision to bypass even the most effective prevention controls.

An effective Principal Hazard Management Plan should address the issues around human error and violations.

A useful model to understand human error and violations is the Human Factors Analysis and Classification System (HFACS). This system was developed by Dr Scott Shappell and Dr Doug Wiegmann (2003) and was originally used by the US Air Force to investigate and analyse human factor aspects of aviation. HFACS is heavily based upon James Reason’s swiss cheese model (Reason, 1990).

HFACS  draws a distinction between errors and violations.

Errors are unintended and are classified as either decision errors, skill-based errors or perceptual errors.

Violations are intentional and can be either routine or exceptional.

The routine violation arises when there is a culture of acceptance around certain violations. Human decision-making is influenced by the environment in which they operate. Management has the ability to shape the environment and create a safety culture that discourages routine violations.

The exceptional violations are a serious matter and require a fair discipline process to address. Some organisations use the concept of ‘Cardinal Rules’ or ‘Golden Rules’
to demonstrate that serious safety breaches may result in the termination
of employment.

Figure 4 illustrates the application of the Principal Hazard Management Plan and management safety interventions to the Human Factors Analysis and Classification System.


HFACS suggests that the approach to preventing fatalities should be twofold.

The Principal Hazard Management framework provides engineered solutions to prevent an incident occurring and with the appropriate controls should prevent human error from contributing to the incident.

Management intervention strategies such as safety programs and a fair discipline process will address violations. These intervention strategies will reduce the likelihood of people deliberately bypassing the controls within the Principal Hazard Management framework.

It is important to manage the human in the system as well as implement effective controls.

Contributors to an effective Principal Hazard Management Plan

Consultation with those people who have to deal with the hazards at the workplace is central to developing any safety and health management system.

The legislation within Queensland calls for a tripartite approach to safety, with cooperation encouraged between the regulator, private industry and the worker. This approach has encouraged ownership of the safety system with the work force and provided a mechanism for the regulator to provide advice to industry.

The technical expertise required to identify appropriate controls or set appropriate TARPS within the Principal Hazard Management Plan may not exist within the tripartite arrangement.

There is a role for a content expert to be involved with the development of an effective Principal Hazard Management Plan.

Figure 5 illustrates the role of the content expert providing advice to the tripartite arrangement.



It is difficult to measure the effectiveness of controls that manage low-probability high-consequence events.

There is a tendency within industry to question whether the prevention controls are necessary when the probability of an incident occurring is low. In some cases this may result in the removal of prevention controls. It has been a common theme in inquiries into major disasters that prevention controls that were initially in place were removed or bypassed over time.

Another contemporary challenge is that difficult economic times may drive operators to adopt low-cost solutions that may not be effective. Administrative controls may be seen as an attractive low-cost prevention control but they may not be effective.

Many operations measure their safety performance in terms of Total Recordable Injury Rate. The greater proportion of injuries is minor in nature and involves muscular strains and small cuts and bruises. The mechanisms behind these minor injuries are generally not the same as the mechanisms behind a serious injury or a fatality. It is important for operations to not lose sight of the principal hazards whilst managing the minor injuries. Personal protective equipment may be an appropriate control in managing the minor injuries but may not be an appropriate control for a principal hazard.

Finally, we need to challenge the mindset of blaming the victim when human error contributes to a serious accident. An effective Principal Hazard Management Plan should error-proof
the system.

All too often the cause of a fatality is attributed to a person not following a procedure. It is important to draw the distinction between a violation and an error and address each with appropriate strategies.

Summary and conclusions

The Principal Hazard Management Plan is developed using risk management principles.

The following steps provide a guideline on how the plan should be developed:

  • perform a site-wide hazard identification
  • risk assess the hazards in consultation with the affected workforce to identify the high consequence hazards
  • select prevention controls with the assistance of a relevant content expert
  • challenge the prevention controls against the hierarchy of controls
  • include the prevention controls in a critical control register
  • determine appropriate TARPS with the assistance of a relevant content expert
  • monitor the identified critical controls and report compliance to senior management
  • test the first response plans and the emergency response through mock exercises
  • manage the ‘safety culture’ to prevent intentional breaches of critical safety controls.

The end goal is to ensure each and every employee returns home safely at the end of their shift.

An effective Principal Hazard Management Plan will assist in achieving this goal.


The author would like to acknowledge the Queensland Department of Natural Resources and Mines for providing the support to write this paper. 


Coal Mining Safety and Health Act, 1999,
Queensland Government.

Coal Mining Safety and Health Regulations, 2001, Queensland Government.

Reason J,1990. Human Error, New York, Cambridge University Press.

Wiegmann D A, and Shappell S A, 2003. A Human Error Approach to Aviation Accident Analysis: The Human Factors Analysis and Classification System, Burlington V T, Ashgate Publishing Ltd.

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