In determining the type of height safety system required for a particular job it can be useful to apply a hierarchy of control.
Using a risk prevention hierarchy it is possible to determine the highest level of control that can be achieved when working with a height hazard.
The levels to be considered in prevention of falls are;
- Elimination(highest level of control). Can the work be done on the ground avoiding exposure to working at height? Could the risk of falling be eliminated by use of a solid construction. A redesign should be considered to eliminate the need for working at height.
- Substitution. Can the work be accessed using permanent safety systems that don’t need to be altered or taken down after installation, such as platforms, walkways or guardrails, which eliminate the hazard of falling?
- Engineering Controls. These controls essentially providing solution from a hazard as distinct from removing the hazard altogether, an example being putting in a no access sign. As a consequence, they are lower on the hierarchy of control because they require a human interaction to institute the isolation procedure.
- Administrative Controls. These involve implementing temporary barriers / measures to prevent people from reaching the area where a fall risk can occur, an example would be temporary roof edge protection guardrail. Unlike a permanent barrier, temporary measures are lower on the hierarchy because they can be moved or tampered with and are as only as good as the barrier and implementation method employed by those using them to control the hazards.
- Personal Protective Equipment (lowest level of control). PPE is considered to be the last measure of resort and all other means of practical access have been eliminated under methods proposed by the hierarchy. The work would be carried out by use of roof anchors or static lines? The installation of these components need to be undertaken by a specialist, workers need training and the preferred work method would be Fall Restraint.
When applying the working at height hierarchy of control it is always preferable to work at the highest level of control and lower levels should only be used when these are not practicable.