Under regulations 627-629 of the Work Health and Safety (Mines) Regulations 2022 (WHS Mines Regulations), the mine operator of a mine must identify all principal mining hazards at the mine and prepare a principal mining hazard management plan (PMHMP) for each principal mining hazard identified at the mine.
A PMHMP sets out the controls and procedures a mine operator must use to manage serious risks linked to identified principal mining hazards (PMHs).
A PMH is any activity, process, procedure, plant, structure, substance, situation or other circumstance in mining operations that has a reasonable potential to result in fatalities either in a single event or through recurring incidents.
Each PMH requires its own PMHMP as one of the key component of a mine safety management system (MSMS). The MSMS provides a structured framework that integrates the mine's policies, systems and procedures to ensure safe and effective operations.
Principal mining hazards
Depending on the nature and scale of mining operations, PMHs may include:
- geotechnical instability
- uncontrolled inrush of substances
- mine shafts and winding systems
- roads or other areas where mobile plant operate
- fire or uncontrolled explosions
- gas outbursts in underground coal mines
- spontaneous combustion in underground coal mines
- any other principal mining hazard identified by the mine operator.
Identifying principal mining hazards
PMHs at a mine are site specific and can vary with the work being performed and the associated risks. Mine operators must identify and assess PMHs individually and collectively to understand how risks may interact and influence one another.
Hazards and their associated risks can also evolve over time as working conditions change, hence mine operators must regularly review and update their control measures to ensure ongoing safety.
Risk assessment
Once a PMH is identified, the mine operator must thoroughly assess the risk, analyse the hazard and clearly record the findings in the PMHMP for that hazard.
The risk assessment must be carried out by a competent person or group with an appropriate process that:
- considers the likelihood and severity of potential incidents
- examines existing control measures
- identifies any additional actions required to effectively manage the hazard.
The risk assessment process should be systematic, evidence-based and tailored to the specific characteristics of the principal mining hazard.
Risk control measures
By identifying and assessing PMHs, mine operators can determine the most effective risk control measures to manage associated risks.
Mine operators must ensure that risk controls are clearly defined so they can be measured, reviewed and fully documented in the relevant PMHMP.
Critical control measures
Critical control measures specifically target the most significant risks in a workplace including fatalities, major environmental damage or equipment loss. Critical controls must define and document:
- objectives
- performance standards
- influencing factors
- verification methods
- trigger points for urgent action (trigger action response plans).
Critical controls must be integrated into both a mine’s PHMPs and MSMS. They must be regularly monitored and reviewed with performance indicators to show how effective the controls are and how well they’re being managed.
Mine sites should use checklists and routine testing to confirm that controls are implemented and functioning properly.
Using the hierarchy of controls is the most effective method for selecting and applying safety measures.
For more information on the applying the hierarchy of control, see the How to manage work health and safety risks: Code of practice or the Emergency management for Western Australian mines: Code of practice.
Use of trigger action response plans (TARPs)
A trigger action response plan (TARP) outlines the steps for workers to follow when mine site conditions deviate from normal conditions.
A TARP should only be developed once a thorough risk assessment confirms the most effective controls for managing the identified hazard. Trigger levels are then determined based on signs of the increased hazard risk.
For example, trigger levels in a TARP might range from:
- Level 1: conditions are normal and routine monitoring applies
- Level 2: a minor deviation requires increased observation
- Level 3: an elevated risk demands restricted access or operational changes
- Level 4: critical conditions require immediate evacuation and emergency response.
The TARP must also clearly outline what workers, supervisors and mine managers should do at each trigger level once those risk indicators are reached.
For more guidance on TARPS, see the Emergency management for Western Australian mines: Code of practice.
Requirements of a PMHMP
A PMHMP must be clear, easy to understand and readily accessible for all personnel. It must:
- describe each principal mining hazard at the operation
- set out how the risks arising from each hazard have been assessed
- clearly define the control measures and implementation to manage the risks associated with each hazard.
To ensure effective implementation, a PMHMP must detail risk assessment outcomes and required actions, and provide information, training, instruction and supervision.
The plan should also define triggers for shutdowns, reviews or investigations and document the actions required when controls are missing or fail to perform.
When preparing your PMHMP, consider how it will be established, implemented and integrated with other plans. Any development or reviews of a PMHMP should be undertaken in consultation with relevant workers and representatives.
Performance standards
To measure its effectiveness, a PMHMP must include performance standards and a system for auditing and reviewing how well risk controls are planned, implemented and maintained.
Audit
PMHMPs must be audited regularly by qualified individuals through both internal and external programs to assess their adequacy, implementation and compliance.
Audits should review hazard assessments, evaluate control effectiveness, analyse incident data, assess inspection outcomes and verify exposure compliance.
The Principal mining hazard management plans: Self-assessment has been developed to assist mine operators determine whether their PMHMPs are compliant with the legislation.
Review
Regulation 629 of the WHS Mines Regulations requires mine operators to update a PMHMP following changes in risk controls caused by incidents or altered hazard conditions.
The review should check that the controls for the hazard are still appropriate, align with current best practice and effectively manage the risks linked to the PMH.
When a PMHMP is revised, the updated plan and risk assessment must be reissued and communicated to all workers. Mine operators must ensure that workers are informed of the changes and receive the necessary training. New workers should also be inducted and trained in the risks and controls outlined in the revised plan.
For further guidance on performance measures, reviews and audits, read the Mine safety management system: Code of practice.