The Hierarchy of Controls is the fundamental framework used in Work Health and Safety (WHS) to manage risks. It is an inverted triangle that ranks risk control measures from the most effective to the least effective.
When developing a Safe Work Method Statement (SWMS) or Risk Assessment, you are legally required to work your way down this list. You must always aim for the highest level of control that is reasonably practicable.
Level 1: Elimination (The Best Control)
Physically remove the hazard. This is the most effective control because the risk is completely gone.
- Example: Instead of working at heights to clean windows, use a window cleaning drone or a pole system from the ground. The risk of falling is eliminated.
Level 2: Substitution
Replace the hazard. Replace the dangerous item or process with something safer.
- Example: Replace a solvent-based chemical with a water-based detergent. The risk is still there, but it is lower.
Level 3: Engineering Controls
Isolate people from the hazard. Use mechanical devices or physical barriers to protect workers.
- Example: Install guard rails on a roof edge. The fall hazard exists, but the rail prevents the person from reaching it. Use machine guarding to prevent contact with moving parts.
Level 4: Administrative Controls
Change the way people work. Use procedures, training, signs, and rosters to limit exposure. These controls rely on human behaviour, which makes them less reliable.
- Example: Rotate workers to limit noise exposure time. Put up "No Entry" signs. Conduct training on safe lifting techniques.
Level 5: Personal Protective Equipment (PPE) (The Last Resort)
Protect the worker with gear. PPE is the least effective control because it does nothing to change the hazard itself. If the PPE fails or is not worn, the worker is exposed to the full risk.
- Example: Hard hats, safety glasses, high-vis vests, gloves.
Why "PPE" is Not Enough
A common mistake in amateur risk assessments is to jump straight to PPE (e.g., "Hazard: Dust. Control: Wear mask").
SafeWork Inspectors will ask: "Why couldn't you eliminate the dust? Why couldn't you use water suppression (Engineering)?"
You must demonstrate that you considered the higher-level controls first. PPE should only be used as a backup or in conjunction with other controls, never as the primary solution if a better option exists.
Applying This to Your SWMS
When writing your SWMS, look at every hazard and ask: "Can I eliminate this?" If not, "Can I substitute it?" Keep going down the list until you find the most effective solution that is reasonably practicable for your site.
Want ready-made risk language? Download a risk management plan or SWMS packs with pre-written controls.