Guidance about the isolation of hazardous energies

A range of hazardous energies exists in mobile and fixed plant in mining operations, such as stored, electrical, and mechanical energies. During normal operating conditions, workers are generally protected from these energies by controls such as the plant’s design and guarding.

However, when normal operating conditions are interrupted during work such as:

• installation
• inspection
• repair
• adjustment
• maintenance
• clearing an obstruction
• commissioning
• testing
• cleaning
• decommissioning
• dismantling

the consequences can be significant if isolation controls are deficient, removed, bypassed or deactivated and people are exposed to hazardous energies. It is important to ensure potential exposures to hazardous energies during such work are identified and controlled. The consequences of unwanted events can be serious or even fatal.

In the past, isolation processes in the mining industry were not given adequate emphasis. It was common practice to use tags only to identify that a circuit or item of plant was deactivated or de-energised and that personnel may be working on or around it. In many instances, the potential sources of hazardous energies were not recognised and isolation was not understood or properly applied.

A guideline on isolation of hazardous energies associated with plant in Western Australian mining operations is available for industry use.

The guideline provides information on the development of safe systems of work associated with the isolation of hazardous energies, where protection is required from:

• the movement or operation of plant
• the movement of materials handled by plant
• contact with energy
  • used to operate plant
  • used to carry out processes associated with plant
  • produced or carried by plant
  • stored within plant.

For an introduction to the damage that can be done by stored energy, see the toolbox presentation below on improving hazard awareness.