When Are Critical Controls Required by Mining Legislation?
A Practical Refresher
Definitions
Material Unwanted Event (MUE), at a mine, means an unwanted event in relation to which the potential or real consequence to safety or health exceeds a threshold defined by the operator as warranting the highest level of attention.
Critical control means a risk control measure for a mine that is critical to:
prevent a material unwanted event at the mine; or
mitigate the consequences of a material unwanted event at the mine.
(Defined in MQSHA, and almost identically in CMSHA.)
The MUE Threshold Is the Trigger
Critical controls are only required by legislation in relation to Material Unwanted Events — not every perceived hazard or incident. The operator sets that threshold themselves, but guidance is clear on what the minimum should be.
What Is the Typical Threshold?
For critical control management, the threshold is typically set, as a minimum, at a multiple-fatality event. Some operators may choose to set the threshold at a single fatality — this is permissible, but it will increase the number of MUEs, critical controls, and verification activities required. (RSHQ — Identifying and Managing Critical Controls, Mineral Mines & Quarries)
For coal mines specifically, QGN35 narrows this further: the scope is strongly adopted as limited to Principal Hazards, where the threshold for an MUE is more than one fatality. Should a coal mine operator determine the threshold to be a single fatality, the guidance can still be adopted to assist. (QGN35 — The Integration of Critical Controls into PHMPs for Coal Mines in Queensland)
Practical Implication for My Competency Expert
This threshold framing of MUEs — and by extension critical controls — highlights the importance of the competence of the people responsible for implementing and verifying those critical few controls.
Competence is not just an administrative matter. It's the difference between a control functioning and catastrophically failing.
(Photo by ThisisEngineering on Unsplash)