The Hierarchy of Control for Working at Height

Where it is reasonably practicable to do so, employers must find a way to avoid the need to work at height altogether before implementing any other controls. 

When deciding what is ‘reasonably practicable’ the financial, time or trouble costs of prevention or control must be measured against the risk itself. Employers must implement the highest level of control measures in the hierarchy unless they can prove that the risks are insignificant compared to the overall cost (financial, time or trouble) needed to implement them. 

Examples of control measures that would avoid the need to work at height include:

• Using extension equipment, such as extension poles to paint or telescopic tools for window cleaning, in order to safely carry out a task from ground level.
• Assembling equipment at ground level and then erecting it using safe mechanical lifting equipment rather than assembling at height.
• Using binoculars to inspect a roof from a safe area on an adjacent building. 

If the work at height cannot be avoided and there is still a risk of a fall leading to injury, then the second level of the hierarchy of control is to prevent a fall from occurring. 

To prevent a fall employers must firstly use an existing safe place of work to complete the work. If this is not reasonably practicable then suitable work equipment should be provided to prevent a fall. There are two types of protective work equipment that can prevent a fall; preventative collective protection and preventative personal protection. 

• Preventative collective protection – Employers must first consider using collective protection measures before personal protective measures to prevent a fall from height. Collective protective equipment is more effective as it protects everyone and does not require action from the user in order to work effectively. Examples of collective prevention include, a working platform with guard rails or other suitable edge protection, scaffolding and low-level access platforms. 
• Preventative personal protection – If a fall cannot be prevented by using collective protection then preventative personal protection, also known as fall restraint PPE, should be used. As this equipment only protects individuals and requires action from the individual to be effective, it is lower down the hierarchy. An example of personal protection includes a fall restraint harness with a lanyard secured to a suitable anchor that prevents an individual from reaching a high-risk area where they could fall. 

Examples of control measures that would prevent a fall while working at height include:

• Fitting access equipment, such as scaffolding and mobile elevating work platforms, with guard rails.
• Using a harness with a short lanyard to prevent an individual accessing an area where they could fall, such as a roof.
• Working from an existing safe place of work that does not require the use of additional work equipment to prevent a fall. 

If work at height cannot be avoided and falls cannot be prevented, then the next level of the hierarchy involves minimising the consequences of a fall. This is achieved by selecting protective equipment to minimise or mitigate the distance and severity of a fall. 

Mitigating a fall is the lowest level of the hierarchy and should only be considered when it is not reasonably practicable to avoid or prevent falls from height. 

Mitigation equipment requires a high level of training and skill for both installation and use. As with fall prevention equipment, different equipment can provide collective or personal protection. Collective mitigation equipment is more effective than personal mitigation equipment and should always be implemented in the first instance where reasonably practicable. 

A fall arrest harness is an example of personal mitigation equipment. This equipment must only be used once all other steps of the hierarchy have been exhausted, including collective mitigation. Unlike fall restraint PPE, fall arrest PPE, such as a fall arrest harness, cannot prevent a fall from happening, however it can minimise the distance and consequences of a fall by stopping the user before they hit the ground. To be effective, fall arrest PPE, such as a harness, must have a secure anchor point and clearance from the ground so that the shock-absorbing lanyard can deploy. 

It’s important to note that the risk of further harm makes fall arrest PPE less safe than fall restraint PPE. For example, falling while using fall arrest PPE can cause the user to experience suspension trauma. This occurs when an individual becomes unconscious when suspended. In this instance it is essential that they are rescued as soon as possible according to an employer’s rescue plan. This risk of additional harm means that fall arrest PPE should legally only be used when a fall cannot be prevented. 

Examples of control measures that would minimise the distance and severity of a fall while working at height include:

• Positioning nets or soft-landing systems under work at height areas.
• Providing employees with personal fall arrest equipment.
• Providing regular training so that employees know how to use equipment safely and know what to do in the event of a fall.