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Hierarchy of controls

The hierarchy of controls ranks risk controls most-to-least effective: elimination, substitution, isolation, engineering, administrative, then PPE last.

By Chalkline. Last updated 25 May 2026. Verified 25 May 2026.

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The hierarchy of controls is the WHS ranking of risk-control measures from most effective to least effective. It is the framework behind every risk assessment and SWMS: you must work down the list and use the highest-order control that is reasonably practicable, not jump to the easy one.

The order

Under the model WHS Regulations (reg 36), the levels are:

  1. Elimination: remove the hazard entirely (do the work at ground level instead of at height; design out the confined space).
  2. Substitution: replace it with something less hazardous (a water-based product for a solvent one).
  3. Isolation: separate people from the hazard (barricade, exclusion zone, guarding).
  4. Engineering controls: a physical change that reduces risk (edge protection, a guard rail, local exhaust ventilation, mechanical lifting).
  5. Administrative controls: procedures, training, signage, permits, job rotation.
  6. PPE: personal protective equipment (helmet, gloves, respirator, harness).

The first three (elimination, substitution, isolation, engineering) are grouped in the Regulations as the higher-order ways to minimise a risk that cannot be eliminated; administrative controls and PPE come after.

The two principles that matter

  • Higher controls first. You apply the most effective control that is reasonably practicable. Skipping straight to a lower-order control when a higher one is available is non-compliant.
  • PPE is the last resort, never the first. PPE only protects the wearer, only when worn correctly, and does nothing about the hazard itself. A control plan that opens with “wear a mask” instead of removing or isolating the hazard fails the hierarchy. PPE is the backstop after the higher controls, or the top-up alongside them.

In practice you often combine levels: an exclusion zone (isolation) plus a permit (administrative) plus a harness (PPE), for example. The point is that PPE is not doing the heavy lifting on its own.

For a builder

  • Write controls top-down in the SWMS. For each hazard, ask “can I eliminate it? substitute? isolate? engineer it out?” before you reach for PPE. A SWMS that lists only PPE will not survive an inspector’s read.
  • PPE is the floor, not the plan. Hard hats and hi-vis are assumed; the real control is the elimination, isolation, or engineering above them.
  • It is the test an inspector applies. When something goes wrong, the question is whether a higher-order control was reasonably practicable and skipped.

Also known as: control hierarchy, hierarchy of risk controls.

See also

Last updated: 2026-05-25. Verified: 2026-05-25. Quarterly review for currency.

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