What are the options for risk control measures?
In any workplace, there are many hazards that could be addressed but it may not be practicable to address all of them. Attention should focus on unwanted events that are reasonably foreseeable. Selection of the most appropriate control involves balancing the cost of implementing each option against the benefits derived from it and the costs associated with an unwanted event.
Where large reductions in risk may be obtained with relatively low cost or effort, such options should be implemented. Rare but severe risks should be considered carefully as they may warrant controls even if they are not justifiable on strictly economic grounds. In general, workers’ exposures to hazards should be as low as reasonably practicable.
What is the hierarchy of control?
An effective approach to risk control is to apply the hierarchy of control. The higher up the hierarchy of control a measure is, the greater the protection it can provide.
From most to least effective, control measures are grouped as follows.
Elimination - remove or design out the hazard (i.e. no exposure means no risk)
Substitution - use something else (e.g. substance, process) that has a lower level of risk
Isolation or segregation - separate people from the hazard
Engineering controls - make a structural change to the working environment or work process to add a protective barrier between the hazard and workers
Administrative controls - if a risk remains after considering higher order controls, reduce exposure to hazards through administrative means such as compliance with procedures and instructions, or by providing training or changing work scheduling
Personal protective equipment (PPE) - PPE is the last line of defence should other controls prove ineffective or not practicable, or it can be used to support other control measures.
Isolation or segregation methods (e.g. guarding) are sometimes grouped with engineering controls.
The protection offered by PPE relies on the correct selection, fitting, maintenance and use.
Often more than one control measure will be necessary to address the risk factors.
Where the risk of exposure is unacceptably high, immediate action may be necessary to control the exposure before long-term control, or more permanent or more costly, measures can be introduced.
For example, workers may be required to wear respiratory protection to control exposure to a hazardous substance in the short term until more effective local exhaust ventilation can be installed.
Why is it important to monitor and review control measures?
Risk profiles rarely remain constant in the mining environment. Risks and the effectiveness of control measures need to be monitored to ensure changing circumstances do not alter risk priorities or introduce new hazards.
A risk profile considers the hazards from a consequence and likelihood perspective across the entire operation.
Ongoing review is essential to ensure that the management plan remains relevant. Factors that affect the likelihood of an unwanted event and its consequences may change, as may the factors that affect the suitability or cost of the various control options.