When an employee is injured in the workplace, after any medical assistance has been provided, the next step is to review the events leading up to the incident. The outcome of the review will often result in tighter controls, better training, or more personal protective equipment being offered. But a better question is to ask does the risk need to exist in the first place and can it be eliminated entirely?

This is where the hierarchy of control comes in. When considering the causes and outcomes of a workplace incident or risk identified by a risk assessment, the best course of action is to work through a series of possible risk control measures. Eliminating the risk completely is obviously a better solution than simply reducing its chance to occur.

What is the Hierarchy of Control?

The hierarchy of control is a pyramid of steps that should be considered in sequence when evaluating the ways to remove or reduce a discovered risk. Each step in the pyramid should be considered but preference should be given to control measures higher up the hierarchal structure than those at the bottom. The most effective risk control will often also come from implementing a number of levels from the hierarchy simultaneously.

What are the risk control measures, and where does each one fit into the hierarchy?


Eliminating the Risk (Level One)

Eliminating the risk is the highest level in the hierarchy. Removing a risk completely is always the preferred option when available as it means there is zero chance of a future incident occurring. While it may not be possible to remove the risk completely in most cases, it should always be the first control measure explored. An example of risk elimination could be providing extending poles operated from the ground to access a high window latch rather than requiring climbing a ladder, which presents a risk of falling.


Substituting the Risk (Level Tw0)

The next level down in the hierarchy is risk substitution. Risk substitution is the process of removing a risk by replacing it with another risk that is either less likely to occur or less severe in its potential damages. Substitution is less preferred to eliminating the risk completely as it still leaves a risk present, albeit in a reduced form. An example of risk substitution could be to replace noisy equipment with a quieter option or it could be replacing a highly toxic chemical with a less dangerous version. It’s important to conduct a new risk assessment after the substitution has been completed to identify any new risks created by the substitute process.

Isolate the Risk (Level Three)

The third level in the hierarchy is risk isolation. Risk isolation is performed by placing some form of barrier between the employee and the risk factor in order to provide protection. The key difference between this level and risk elimination (level one) is that the risk is still present, with the employee only shielded from it by the barrier. If the barrier were to fail or require bypass the risk would return to being uncontrolled. Risk isolation could be enacted by placing dangerous machinery in a separate room from the operating and installing remote control systems.

Engineering Controls (Level Four)

Engineering risk control is the process of designing and installing additional safety features to workplace equipment. Safety features could be installing more stringent ventilation systems in noxious environments or installing guardrails on a raised walk-way.

Administrative Controls (Level Five)

Level five of the hierarchy is administrative controls. These are measures the management and chain-of-command can implement to reduce the likelihood of a risk occurring. Measures could include providing dedicated training targeted at the risk or arranging work schedules to limit exposure times in hazardous environments.

Personal Protective Equipment (Level Six)

The final level in the hierarchy of risk control is the use of personal protective equipment (PPE). It’s likely that this level will be utilised regardless of what other levels are also being used to control a risk, however, it remains at the bottom of the hierarchy as it doesn’t remove or reduce the risk itself. Instead, this level is designed around assuming an incident will occur and protecting the employee from harm when it does. Personal protective equipment is items such as hard-hats, noise-reducing ear protection, or cut-resistant gloves.

How does the Hierarchy increase Workplace Safety?

The risk control measures are implemented in a hierarchy in order of their effectiveness at controlling the risk and preventing accident or injury. Risk elimination sits at the top of the hierarchy as there is no better way to prevent accident or injury than completely removing the risk.

Following down the hierarchy, isolating a risk completely, for example moving a loud and vibrating machine into a room to be controlled remotely, is better than merely installing some soundproofing (engineering) or limiting employee exposure times (administrative).

Personal protective equipment is a somewhat unique control on the hierarchy, as it is both the least effective (sitting at the bottom) and most commonly used. That is because PPE still leaves the risk uncontrolled — the employee is only personally protected from injury when the risk causes an incident.

PPE is unique, though, as it will usually be used in conjunction with whatever other risk control measures have been implemented. It acts as a final line of defence and is also easy and cheap to implement compared to engineering completely new machinery or safeguards, making it perfect to use in addition to other controls. It also offers the additional benefit of protecting the worker from injury resulting from undiscovered risks.

Following the hierarchy means that when implementing risk controls measures you will always implement the most effective, and therefore safest, option before implementing measures that may leave room for an incident to still occur.

It is good practice to self-enforce the hierarchy, however, in some jurisdictions, it is also a legal requirement to attempt to eliminate a risk before attempting any other control measures.

Conserve can help you ensure your workplace is as safe as possible. Contact us today to see how.

For more information contact us on +61 2 8883 1501, enquiries@conserve.com.au or subscribe to our newsletter for regular updates.

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