The hierarchy of risk control is a long-established tool in determining the most effective methods of mitigating an identified safety risk. But how does it relate to height safety?
The hierarchy of risk control is a standard tool used to assist in determining how workplace safety risks should be mitigated. Its purpose is to guide a person through the different types of risk control available, ranked from most to least effective, so they can find the most appropriate control to use.
The typical hierarchy that people will come across can have five or six different levels of control. Depending on which one you are looking at, some of the definitions can be slightly different or merged. But the fundamental underpinnings are universal.
That universality can increase the level of difficulty in understanding what each control means in practice, in each work environment. When it comes to working at height, here are some starting points for each to consider.
Elimination
Elimination is the most effective form of risk control. As the name implies, this involves removing the risk entirely.
For working at height, this means simply not doing that – not working at height in the first place. If you are not working at height, then you are not at risk of a fall from height.
Practically, this level of control can only be implemented at the design stage of a building. Actions like placing HVAC and air-conditioning equipment on the ground, as opposed to the roof eliminate the need to work at height.
Realistically, it is unlikely the need to work at height can be eliminated completely.
Elimination is the only risk control that takes the probability of the accident occurring to zero. All the other elements of the hierarchy of control carry at least some element of risk.
This is where the knowledge to perform a comprehensive risk assessment is required.
Substitution control
Substitution involves replacing the original risk with another risk that is less likely to occur or is likely to have a less severe outcome.
This control can take on a couple of different forms when it comes to working at height. For example, instead of climbing a tower to access equipment located at the top (lights, communications and the like) can the work be completed using an elevating work platform (EWP)? Both still involve the need to work at height, but the likelihood of a fall occurring from an EWP is significantly lower compared to climbing the tower itself.
In other situations, it may involve placing scaffolding around a building to enable safe access to areas at height, as opposed to using a fall protection system like roof anchors.
In both cases, the risk of a fall still exists, and the severity of the fall remains unchanged, however substituting other forms of an access with the use of an EWP or scaffolding substantially reduces the likelihood of a fall.
Isolation control
As a risk control, isolation involves making sure that people associated and not associated with the work are unable to place themselves at risk – either from a fall or from a falling object.
Implementing this control in a working at height situation can involve actions like restricting access to doorways and building areas that lead to areas of fall risk.
External ladders and stairways can have hatches and gates installed. Unlocking these requires the correct key, which can only be issued once authorisation to access the work areas is obtained.
This could also involve the use of guardrail to create a barrier between the work area and the edge of a roof.
Engineering control
In the hierarchy of controls, engineering controls is the area where Height Safety Engineers does a lot of its work. Engineering controls typically involve some sort of physical system a worker must engage with to protect against the identified risk.
Engineering controls in height safety typically take the form of a fall protection system. Fall protection systems come in a variety of different shapes and sizes. They can be as little as a simple anchor point and ladder bracket through to elaborate walkway systems, HVAC platforms, static lines, fixed ladders and more.
There are two main ways a fall protection can work. Fall restraint and fall arrest.
Although they are both types of engineering control, fall restraint is generally preferred over fall arrest. Fall restraint works to keep the worker situated in a position where they cannot fall from height. Fall arrest systems work to reduce the distance of free fall, and resultant impact forces, after a worker has fallen from height.
Administration
Second to last on the hierarchy of controls are the administrative ones. This is often also referred to as the documentation, along with training.
Documentation does not physically stop a worker putting themselves at risk out on site. However, having thorough procedures, manuals, plans and inductions will aid in identifying risks, understanding what mitigations are in place, how they are to be used, and what their limitations are.
Personal protective equipment (PPE)
At the bottom of the list is personal protective, or safety, equipment. In the realm of height safety, PPE includes items like a harness, shock absorber, lanyards, ropes, carabiners and the like. Essentially, PPE is the equipment a worker would be using to connect themselves to a fall protecting engineering control.
The need to use PPE as a control is an acceptance that there are elements of the risk to safety that will remain present while the worker goes about their task.
It is generally accepted that PPE should never be the only risk control that is implemented at a workplace. PPE should always be used in combination with other control measures, especially administrative controls (for example, training so the worker understands how the equipment is to be used).
Its place at the bottom of the hierarchy is indicative of its relative effectiveness in protecting workers compared to the other controls.
Understanding your height safety risk control needs
Height Safety Engineers are your partners in protecting people. Our team have a deep understanding of height safety across commercial, industrial, government and infrastructure environments. We bring decades of real work experience to every job.
Start your safety journey and mitigate your risks by talking to the team at HSE. Call us on 1300 884 978, email enquiries@heightsafety.net or fill out the contact form on this page to get in touch.
