The six levels
| Level | Control | Example |
|---|---|---|
| 1 | Eliminate the hazard | Remove the need to work at height by assembling at ground level |
| 2 | Substitute with something safer | Replace a solvent-based cleaner with a water-based one |
| 3 | Isolate people from the hazard | Guard the conveyor; fence the robot cell; remote operation |
| 4 | Engineering controls | Local exhaust ventilation; interlocks; lifting aids |
| 5 | Administrative controls | Procedures, training, signage, job rotation, permits |
| 6 | PPE | Gloves, hearing protection, harnesses, respirators |
Levels 1 and 2 remove the hazard; 3 and 4 reduce the risk through physical means; 5 and 6 rely on people doing the right thing every time, which is why they sit at the bottom.
What the law requires in Australia
The model Work Health and Safety Regulations (reg. 36) require a duty holder to eliminate risks so far as is reasonably practicable and, where that is not possible, to minimise them by working down the hierarchy in order, using a combination of controls where one is not enough. Safe Work Australia's Code of Practice "How to manage work health and safety risks" sets out the method. PPE and administrative controls on their own are acceptable only when higher controls are not reasonably practicable.
How to apply it
- Identify the hazard and who is exposed.
- Start at the top: can the hazard be removed from the task entirely?
- Work down one level at a time, asking what is reasonably practicable, not what is quickest.
- Combine controls: a guard (isolation) plus an interlock (engineering) plus training (administrative).
- Record the control chosen, the residual risk and who maintains the control.
- Review when the task, equipment or incident history changes.
Common mistakes
- Jumping to PPE because it is quick.
- Treating a procedure as a control that holds without checking it is followed.
- Choosing a control once and never auditing whether it is still in place.
The hierarchy inside daily management
The hierarchy is also the test applied to every corrective action from an incident or near miss: a countermeasure that is only "retrain the operator" sits at level 5 and will not hold. In an A3 or 5 whys, the team is asked which level the proposed action reaches; actions at levels 1–4 are preferred, and the control is then written into standard work and checked on layered audits and safety walks.